International Review of Research in Mental Retardation: v. 8

Internationd Review of RESEARCH IN MENTAL RETARDATION VOLUME 8

Consulting Editors for This Volume Alfred A. Baumeister GEORGE PEABODY COLLEGE NASHVILLE, TENNESSEE

John G. Borkowski UNIVERSITY OF NOTRE DAME NOTRE DAME, INDIANA

Lyle L. Lloyd NATIONAL INSTITUTE OF CHILD HEALTH AND HUMAN DEVELOPMENT BETHESDA, MARYLAND

Paul S. Siege1 UNIVERSITY OF ALABAMA UNIVERSITY, ALABAMA

International Review of RESEARCH IN MENTAL RETARDATION

EDITED BY

NORMAN R. ELLIS DEPARTMENT OF PSYCHOLOGY UNIVERSITY OF ALABAMA UNIVERSITY, ALABAMA

VOLUME 8

1976

@

ACADEMIC PRESS New York San Francisco London A Subsidiary of Hurcourt Brace Jovanovich, Publishers

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7

PRINTED IN THE UNITED STATES OF AMERICA

Contents

ListofConMbutors

ix

Prefuce

.................................................. ............................................................

xi

..........................................

xiii

Contents of Previous Volumes

Self-Injurious Behavior

Alfred A. Baumeister and John Paul Rollings

.................................................. ....................... .............................. Summary and Conclusions ........................................ References ....................................................

I. Introduction

11. Theoretical Accounts of Self-InjuriousBehavior 111. Modification of Self-InjuriousBehavior

IV.

1 5 16 29 30

Toward a Relative Psychology of Mental Retardation, with Special Emphasis on Evolution

Herman H. Spitz

......................................... .................... ...........

I. Evolutionary Psychology 11. Mental Retardation Viewed as a Thinking Disability 111. A Framework for a Relative Psychology of Mental Retardation IV. SummingUp .................................................. References ....................................................

35 42 43 53 53

The Role of the Social Agent in Language Acquisition: Implications for Language Intervention

Gerald J. Mahoney and Pamela B. Seely I. Introduction

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11. Interacuunal Strategies Associated with Language Development V

...........

57 62

Contents

vi

.

..... ....................................................

111 Implications of the Role of the Social Agent for Language Intervention References

91 98

Cognitive Theory and Mental Development

Earl C . Butterfield and Donald J . Dickerson

. . . . .

I I1 I11 IV . V VI

Introduction .................................................. Recent Developments in Experimental Psychology ..................... Explanation by Complete Specification of Unobservables ................ Individual Difference Tests ....................................... Cognitive Instruction ............................................ Postscript ..................................................... References ....................................................

106 107 109 113 127 133 134

A Decade of Experimental Research in Mental Retardation in India

Arun K . Sen I. I1. 111. IV.

Introduction .................................................. Research ..................................................... Anoverview Conclusion .................................................... References ....................................................

..................................................

139 141 164 166 168

The Conditioning of Skeletal and Autonomic Responses: Normal-Retardate Stimulus Trace Differences

.

Susan M . Ross and Leonard E Ross

. . . . . .

I Introduction .................................................. I1 Retardation and the Stimulus Trace Concept I11 Stimulus Trace Decay in Classical Conditioning: Background IV Methodological Considerations .................................... V Trace-Delay Conditioning Studies .................................. VI Summary and Conclusions ........................................ References ....................................................

.......................... .............

173 174 176 177 181 189 191

Malnutrition and Cognitive Functioning

J .P .Das and Emma Pivato

. .

I Introduction .................................................. 195 I1 Protein-calorie Malnutrition (EM)and Mental Development ............ 196

vii

CONTENTS

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I11 TheOrissaStudy ............................................... IV. Summary ..................................................... References ....................................................

204 220 221

Remarch on Efficacy of Special Education for the Mentally Retarded

Melvin E .Kaufman and Paul A .Albert0

. . . .

I I1 I11 IV

.................................................. ...............................................

Introduction ResearchReview An Analysis of the Experimental Control of Variabies in Efficacy Research . The Future of Efficacy Research in Special Education .................. References .................................................... SubjectIndex

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225

226 243 251 253 257

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List of Contributors Numbers in parentheses indicate the pages on which the authors' contributionsbegin.

Paul A. Alberto, Georgia State University,Atlanta, Georgia (225) Alfred A. Baumeister, George Peabody allege, Nashville, Tennessee (1) Earl C. Butterfield, Ralph L. Smith Center for Research in Mental Retardation, Universityof Kansas Medical Center, Kansas City,Kansas (105)

J . P. Das, Centre for the Study of Mental Retardation and Department of Educational Psychology, Universityof Alberta, Edmonton, Canada (195)

Donald J . Dickerson (105), University of Connecticut, Storrs, Connecticut (105) Melvin E. Kaufman, Georgia State University,Atlanta, Georgia (225) Gerald J . Mahoney,. Department of Psychology, University of Rochester, Rochester, New York (57) Emma Pivato, Centre for the Study of Mental Retardation and Department of Educational Psychology, University of Alberta, Edmonton, Clanada (195)

John Paul Rollings,Partlow State School and Hospital, Tuscaloosa, Alabama (1) Leonard E. Ross, Universityof Wisconsin,Madison, Wisconsin (1 73)

Susan M. Ross,University of Wisconsin,Madison, Wisconsin (173) Pamela B. Seely, Departmernt of Psychology, University of Rochester, Rochester, New York (57) Arun K. Sen, Department of Psychology, University of Delhi, Delhi, India (139)

Herman H. Spitz, Edward R. Johnstone 7hining and Research Center, Bordentown, New Jersey (35)

*Present address: Special Education Research Program, University of California at Los Angeles, Los Angeles, California 90002.

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Research in mental retardation has never enjoyed great popularity in the scientific community. But over the years it has attracted a few serious investigators who developed and pursued systematic research programs. In the main, these efforts have adopted a basic science orientation and the focus has been on problem areas such as learning, memory, discrimination, attention, and higher cognitive processes. Such research is sometimes misunderstood and, therefore, unappreciated. Most researchers pursuing this line of investigation are persuaded that in order for remediation and alleviation of retarded behavior to occur, the understanding of basic processes is necessary. Moreover, they recognize that this can come about only through tedious labor in the behavioral research laboratory. The questions of why a child makes a low score on an intelligence test or grossly underachieves academically cannot be answered simply. While a modicum of behavioral change can sometimes be achieved with superficial “trial and error” efforts with individual children, too often the problem is unresolved due to a lack of understanding of basic processes. Our knowledge of behavioral deficiencies in retarded children and in those with variously labeled learning problems is still in a primitive state. This is understandable in view of the fact that only a handful of behavioral scientists have pursued these problems over a relatively short period of time. Indeed, this type of research emerged as late as the early 1960s. It has gleaned only a small share of research funding, with the lion’s share going to medically oriented studies. More recently other serious obstacles to behavioral research are beginning to take their toll. The climate for research in the United States is poor. Laymen, and even some professionals, expected “breakthroughs” which have not come nor ever will in the form expected. The emphasis is on action programs of various sorts such as deinstitutionalization, insuring legal rights, mainstreaming, and a host of massive efforts, well intended, but based on armchair speculation about the retarded and their competencies. Certainly action programs are being launched on a number of fronts without the benefit of factual information (of the applied or basic type). These efforts have turned attention and resources away from behavioral research. Also, legal and administrative actions to guard individual privacy have made research with the retarded very difficult indeed. xi

xii

Preface

Despite the many obstacles, a trickle of meaningful research of high quality continues and this series attempts to represent the best of it. The present volume, like the previous ones, reflects a wide range of research interests and a high degree of research sophistication. The research represented here encompasses both applied and basic issues.

NORMAN R.ELLIS Universify of Ahbama

Contents of Previous Volumes

Volume 1

A Functional Analysis of Retarded Development SIDNEY W.BIJOU Classical Conditioning and Discrimination Learning Research with the Mentally Retarded LEONARD E. ROSS The Structure of Intellect in the Mental Retardate HARVEY F. DINGMAN AND C. EDWARD MEYERS Research on Personality Structure in the Retardate EDWARD ZIGLER Experience and the Development of Adaptive Behavior H. CARL HAYWOOD AND JACK T. TAPP A Research Program on the Psychological Effects of Brain Lesions in Human Beings RALPH M. REITAN

Long-Term Memory in Mental Retardation JOHN M. BELMONT The Behavior of Moderately and Severely Retarded Persons JOSEPH E. SPRADLIN AND FREDERIC L. GIRARDEAU Author Index-Subject Index

Volume 2

A Theoretical Analysis and Its Application to Training the Mentally Retarded M. RAY DENNY xiii

XiV

Contents of Previous Volumes

The Role of Input Organization in the Learning and Memory of Mental Retardates HERMAN H.SPITZ Autonomic Nervous System Functions and Behavior: A Review of Experimental Studies with Mental Defectives RATHEKARRER Learning and Transfer of Mediating Responses in Discriminative Learning BRYAN E. SHEPP AND FRANK D. TURRISI A Review of Research on Learning Sets and Transfer of Training in Mental Defectives MELVIN E. KAUFMAN AND HERBERT J. PREHM Programming Perception and Learning for Retarded Children MURRAY SIDMAN AND LAWRENCE T. STODDARD Programmed Instruction Techniques for the Mentally Retarded FRANCES M. GREENE Some Aspects of the Research on Mental Retardation in Norway WAR ARNLJOT BJORGEN Research on Mental Deficiency During the Last Decade in France R. LAFON AND J. CHABANIER Psychotherapeutic Procedures with the Retarded MANNY STERNLICHT Author Index-Subject Index

Volume 3

Incentive Motivation in the Mental Retardate PAUL S. SIEGEL Development of Lateral and Choice-SequencePreferences IRMA R. GEIUUOY AND JOHN J. WINTERS, JR. Studies in the Experimental Development of Left-Right Concepts in Retarded Children Using Fading Techniques SIDNEY W.BIJOU Verbal Learning and Memory Research with Retardates: An Attempt to Assess Developmental Trends L. R. GOULET

CONTENTS OF PREVIOUS VOLUMES

xv

Research and Theory in Short-Term Memory KEITH G. SCOTT AND MARCIA STRONG SCOTT Reaction Time and Mental Retardation ALFRED A. BAUMEISTER AND GEORGE KELLAS Mental Retardation in India: A Review of Care, Training, Research, and Rehabilitation Programs J. P. DAS Educational Research in Mental Retardation SAMUEL L.GUSKIN AND HOWARD H. SPICKER Author Index-Subject Index

Volume 4

Memory Processes in Retardates and Normals NORMAN R. ELLIS A Theory of Primary and Secondary Familial Mental Retardation ARTHUR R. JENSEN Inhibition Deficits in Retardate Learning and Attention LAIRD W.HEAL AND JOHN T. JOHNSON, JR. Growth and Decline of Retardate Intelligence MARY ANN FISHER AND DAVID ZEAMAN The Measurement of Intelligence A. B. SILVERSTEIN Social Psychology and Mental Retardation WARNER WILSON Mental Retardation in Animals GILBERT W. MEIER Audiologic Aspects of Mental Retardation LYLE L. LLOYD Author Index-Subject Index Volume 5

Medical-Behavioral Research in Retardation JOHN M. BELMONT

XVi

antents of Previous Volumes

Recognition Memory: A Research Strategy and a Summary of Initial Findings KEITH G. SCOTT Operant Procedures with the Retardate: An Overview of Laboratory Research PAUL WEISBERG Methodology of Psychopharmacological Studies with the Retarded ROBERT L. SPRAGUE AND JOHN S. WERRY Process Variables in the Paired-Associate Learning of Retardates ALFRED A. BAUMEISTER AND GEORGE K E U A S Sequential Dot Presentation Measures of Stimulus Trace in Retardates and Normals EDWARD A. HOLDEN, JR. Cultural-Familial Retardation FREDERIC L. GIRARDEAU German Theory and Research on Mental Retardation: Emphasis on Structure LOTHAR R. SCHMIDT AND PAUL B. BALTES Author Index-Subject Index

Volume 6

Cultural Deprivation and Cognitive Competence J. P. DAS Stereotyped Acts ALFRED A. BAUMEISTER AND REX FOREHAND Research on the Vocational Habilitation of the Retarded: The Present, The Future MARC W. GOLD Consolidating Facts into the Schematized Learning and Memory System of Educable Retardates HERMAN H. SPITZ An Attention-Retention Theory of Retardate Discrimination Learning MARY ANN FISHER AND DAVID ZEAMAN

Studying the Relationship of Task Performance to the Variables of Chronological Age, Mental Age, and IQ WILLIAM E. KAPPAUF Author Index-Subject Index

CONTENTS OF PREVIOUS VOLUMES Volume 7

Mediational Processes in the Retarded JOHN G. BORKOWSKI AND PATRICIA B. WANSCHURA The Role of Strategic Behavior in Retardate Memory ANN L. BROWN Conservation Research with the Mentally Retarded KERI M. WILTON AND FREDERIC J. BOERSMA Placement of the Retarded in the Community: Prognosis and Outcome RONALD B. McCARVER AND ELLIS M. CRAIG Physical and Motor Development of Retarded Persons ROBERT H. BRUININKS Subject Index

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Self-Injurious Behavior'

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ALFRED A BAUMEISTER GEORGE PEABODY COLLEGE. NASHVILLE. TENNESSEE

AND JOHN PAUL ROLLINGS

.

PARTLOW STATE SCHOOL AND HOSPITAL. TUSCALOOSA ALABAMA

. Introduction .................................................. Prevalence of Self-InjuriousBehavior ................................ I1. Theoretical Accounts of Self-Injurious Behavior ....................... A . Homeostatic Function ........................................ I

................................... ............................................. D. Developmental Interpretations .................................. E. Self-Injurious Behavior as Learned Behavior ........................ I11. Modification of Self-InjuriousBehavior .............................. A . Differential Reinforcement of Alternative Behavior .................. B. Removal of Positive Reinforcement .............................. C. Physical Punishment .......................................... D. Collateral Behaviors and Symptom Substitution ..................... IV. SummaryandConclusions ........................................ References .................................................... B. Psychodynamic Formulations

C. Organic Account

1 2 5 6 7 9 10 10 16 17 19 22 26 29 30

.

1 INTRODUCTION

Perhaps the most distressing and bizarre of all the behavioral aberrations that people exhibit are those repetitive or stereotyped acts that produce self-inflicted

' Supported. in part. by U.S. Public Health Service Grant €ID00973 (George Peabody College)

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1

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Alfied A. Baumeister and John Paul Rollings

injuries. There are probably few among us, even those whose clinical experiences have inured us to most of the frailities of humankind, who do not experience a quickened sense of anguish upon witnessing a child beat and brutalize himself. These behaviors immediately pose two fundamental questions: Why do some people repetitively inflict injury upon themselves, and what can be done to modify such behavior? A related theoretical question is: Why does behavior persist in the face of severe consequences, where common sense tells us that such behavior is a contradiction of the natural law of effect? In turn, these questions become a myriad of definitional, scientific, and practical issues. The term self-injurious behavior (SIB) is used here to refer to acts which are usually highly repetitive or stereotyped in character and which result in direct physical damage to the person. The clinical use of the term emphasizes events which are excessive, unusual, bizarre, and without any immediately apparent desirable consequences. Among the most common forms of SIB are head banging, eye gouging, biting of extremities and oral structures, scratching, and rectal “digging.” In addition, certain types of SIB often are accompanied by other rhythmic stereotypes such as body rocking (Baumeister & Forehand, 1973; DeLissovoy, 1961; Levinson, 1970). The temporal pattern or the topography of these behaviors may be stereotyped and rhythmic (Lester, 1972), or they may be under control of very specific stimuli and exhibited only in certain contexts (Bachman, 1972; Forehand & Baumeister, 1976). Actually, marked individual differences can be observed with respect to these behaviors in their severity, topography, duration, and tenacity. In some instances the response produces only mild damage and the behavior may be voluntarily interrupted until the lesion heals. In the most extreme cases, an individual may beat or gouge himself to unconsciousness or blindness or possibly even death unless restrained. A variety of descriptive labels have been applied to these behaviors including such terms as masochistic, self-punitive, autoagressive, suicidal, destructive, and self-mutilative. In some instances the choice of a particular term may reflect either a theoretical inclination as to the origin of these behaviors or a preference for a particular diagnostic classification system. The term that has the greatest currency, however, is self-injurious behavior. In view of how little is known about the initiating and maintaining conditions of these behaviors, it is probably appropriate to adopt a “neutral” term that describes the physical consequences without implying intent. Prevalence of Self-Injurious Behavior

Most of the SIB literature, largely of the case report variety, applies to individuals diagnosed as mentally retarded, brain injured, psychotic, or autistic. In regard to understanding or managing the problem of SIB, these diagnostic terms are probably not very helpful. There are few studies in which the prevalence of SIB has been reported in “normal” populations, typically young

SELF-INJURIOUS BEHAVIOR

3

children. Information concerning the occurrence of these behaviors among "normal" individuals is important because it allows us to establish a frame of reference for determining when, where, and under what conditions these behaviors should be regarded as excessive. The prevalence of self-injurious behaviors among normal children is surprisingly high, although the figures reported are somewhat variable. Shentoub and Soulairac (1967) followed a group of 300 infants enrolled in a child-care center for periods ranging from 9 months to 6 years. Depending upon age level, between 11 and 17% of these children displayed some form of SIB with the greatest frequency occurring between the ages of 9 to 18 months. Significantly, by the time these subjects were 5 years old, SIB had virtually disappeared. The most frequent form of SIB among infants seems to be head banging. Head banging was observed by DeLissovoy (1961) among 15.2% of his sample of infants who ranged in age between 19 and 32 months. The average age of onset of the behavior was about 8 months, disappearing at approximately 36 months. An observation of considerable interest made by DeLissovoy was that in all instances head banging was preceded by the appearance of other stereotyped movements. There is also some evidence that head banging is most likely to occur during teething episodes (Kravitz & Boehm, 1971). A considerably lower figure was reported by Kravitz, Rosenthal, Teplitz, Murphy, and Lesser (1960) who examined a relatively large sample of 1168 normal infants. They found evidence of head banging in only 3.6% of their subjects. The developmental course of this behavior was very similar to that =ported by other investigators. The average age of onset was 8 months, with an average duration of about 17 months. Again, body rocking was associated with head banging. Kravitz et aL also observed SIB in about 20% of the siblings of the head bangers in their sample, suggesting a familial pattern. Comparative statistics for developmentally disabled children, obtained under fairly comparable conditions of observations, are not abundant. A study recently reported by Kravitz and Boehm (1971) is of particular interest because they followed the development of a variety of rhythmic behaviors in normal, low birth weight, and mongoloid babies. In all, their samples included 340 normal infants, 79 infants with low Apgar scores and neonatal disease, 12 babies with cerebral palsy, and 22 cases of mongolism. Data were obtained for an assortment of stereotyped behavior patterns, including head banging. Head banging was observed in 7% of the normal babies. Boys exhibited these behaviors 3.5 times as frequently as girls, a finding generally confirmed by other investigators. Although the samples of deviant children were small in the Kravitz and Boehm study, it appears that head banging occurs with significantly greater frequency and severity among neurologically impaired children. It is not surprising that the prevalence of stereotyped movements is particularly high among psychiatric groups since the diagnoses may be based in part upon the presence of excessive repetitive movements. Green (1967) observed

4

Alfred A. Baumeister and John Paul Rollings

SIB among 40% of a group of schizophrenic children in a residential center. He also noted that 92% of these individuals had exhibited the behavior from infancy. These findings indicate that SIB represents a response class of long standing duration, a finding that has both practical and theoretical implications. Shodell and Reiter (1968), also working with schizophrenic children, confirmed Green's figure of 40%. A survey reported by Smeets (1971) in which 400 mentally retarded and emotionally disturbed children and adults of a private residential facility were evaluated for SIB revealed a prevalence of about 9%. The most frequently observed forms of SIB were head banging, pinching, scratching, and face slapping. Prevalence of these behaviors was about 3 times as great among males, although severity of SIB was unrelated to sex. In about half the cases, the self-injurious acts were known to have begun before the age of 4 years. Although SIB was observed at various levels of intellectual functioning, the more severe instances were found in the lower IQ range. Other stereotyped behaviors were also observed in most cases, and the majority of these individuals were regarded as hyperactive. Whitney (1966, cited in Smeets, 1971), after surveying 950 residents in a state institution, reported results that are consistent with the figures given by Smeets. Again, about 9% of the residents exhibited SIB. Of the 12 types of SIB observed, biting and head banging were the most frequent. An unpublished survey of Soule and O'Brien (1974) of the SIB in a residential institution for the mentallv retarded revealed that 7.7% of their population of 966 residents displayed some form of these behaviors. The most frequently occurring self-injurious acts, among those exhibiting such behaviors, were selfbiting (54%) and head banging (42%). Prevalence of SIB was greater among females than among males (10.5%versus 5.7%). A somewhat more detailed analysis of SIB among the residents of a large public institution for the retarded was conducted by Schroeder (1974) who reported a figure of about 9%. Head banging was found to be the most frequently observed SIB, occurring in 70% of the cases. It is of some interest to note that within the group identified as self-injurious these behaviors were not related to chronological age, length of institutionalization, stereotypy, sensory disorders, history of physical abuse, or organic neuropathology. This is not to say, of course, that these factors do not differentiate individuals who exhibit SIB from those who do not. In fact, Schroeder found that SIB was related to level of intellectual functioning, ability to communicate expressively, and amount of agression toward others. An unpublished study bearing on these and other issues has been completed recently by Maisto and Baumeister (1975) who, like Schroeder and Soule and O'Brien, surveyed the entire population of a large state institution. Of a total institutional population of 1300 residents, 182 or 14% engaged in SIB. Except for blind residents, the most common forms of SIB were head banging among

SELF-INJURIOUS BEHAVIOR

5

males and biting among females. Eye gouging was the most frequently observed SIB among blind residents. These behaviors occurred with greater frequency among females than among males (1 8% versus 1l%), but were more severe among males. Moreover, females were more likely to engage in multiple forms of SIB. These sex differences are inconsistent with previous findings (e.g., Smeets, 1971). SIB residents were younger and more severely retarded than non-SIB residents, and they had resided in the institution for a longer period of time. Additionally those displaying SIB were more likely to have a diagnosis that included reference to brain injury. Finally, in about 40 to 50% of the cases, other undesirable behaviors such as stereotyped hand waving and aggression to others were observed, a finding generally confirming impressions reported by Schroeder and others. Another, more general, survey has been published that yields some information concerning the prevalence of SIB among institutionalized retarded persons (Ross, 1972). A state-wide census was undertaken to obtain demographic and behavioral information concerning all retarded persons in residence in California institutions. Data were obtained for over 11,000 residents. Of these 12% were found to engage in some form of SIB on a daily basis. Frequency of SIB was particularly high for those individuals in the profound and severe categories of mental retardation. We may expect that as a result of the current Zeitgeist for deinstitutionalization, the prevalence of SIB may actually increase in residential institutions, for these are the individuals least likely to be placed in community programs. Although data concerning the prevalence of SIB and its relationship to various individual characteristics are somewhat sketchy, a few general tentative conclusions are possible: (1) prevalence among normal babies is probably around 7%; (2)in normal children, the behavior, when it is observed, is mild and typically does not persist beyond the age of 3 years; (3) SIB occurs somewhat more frequently among psychiatrically diagnosed individuals, particularly schizophrenic children; (4) estimates of SIB among retarded institutionalized individuals range from about 8 to 14%; (5)it is the intensity and durability of such behaviors that most characterize these individuals; (6) the lower the IQ, the more frequent and severe these behaviors are apt to be; (7) SIB often is fairly repetitious and stereotyped in character, although in many instances it is situation-specific and appears to be under tight stimulus control; and (8) frequently other abnormal behaviors, including motor and verbal stereotypes such as body rocking and screaming, are observed among self-mutilators.

II. THEORETICAL ACCOUNTS OF SELF-INJURIOUS BEHAVIOR

There has been no lack of theoretical speculation concerning the initiating and maintaining conditions for SIB. By and large, most “explanations” of SIB

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Alfred A. Baumeister and John Paul Rollings

are impressionistic and clinical in nature and have not been very rigorously formulated or tested. In fact, it would be difficult to devise meaningful tests of many of these theories because their basic assumptions are stated in such vague and imprecise terms. For purposes of discussion we have classified the various theoretical accounts of repetitious SIB into five categories: Homeostatic, Psychodynamic, Organic, Developmental, and Learning. Actually, these are not mutually exclusive interpretations in that one often includes elements of others. Nevertheless, these various theories can be differentiated primarily in terms of the stress they place upon the contribution of the environment. A Homeostatic Function

Perhaps the most widely accepted explanation is that SIB, especially that of a highly rhythmical and repetitious nature, represents an accommodation by the organism to an environment that consistently fails to provide an optimal or homeostatic level of stimulation. The SIB occurs as an adjustment to increase the organism’s ambient autonomic arousal through self-stimulation. According to this view, when stimulation is low the organism will develop mechanisms for increasing Stimulation, while at the other extreme, given excessive stimulation, the organism will act to decrease stimulation (Baumeister 8c Forehand, 1973). The best support for this interpretation comes from the highly reliable observation that SIB tends to occur in environments, such as institutional wards, that are markedly devoid of meaningful stimulation. Furthermore, deliberate enrichment of the environment may be accompanied by a decrease in SIB. Within this conception, then, SIB serves a stimulatory function. Few direct tests of this theory have been made, at least in regard to SIB. One study has been reported in which an effort was made to measure skin conductance changes during periods of SIB (Kohlenberg, Levin, & Belcher, 1973). Increases in skin conductance levels are considered to reflect heightened arousal. The results of this particular study, although not entirely consistent with the arousal theory, at least in this respect, support the arousal hypothesis of SIB. That is, a positive relationship was observed between rate of SIB and skin conductance. The most commonly accepted view of the arousal hypothesis is that the response mechanism seems to function automatically in that rate of behavior changes in relation to the overall quality and quantity of stimulation. These behavioral changes might reflect a heightened state of arousal mediated through the reticular activating system. Mediation of these behaviors may also occur at the level of the autonomic nervous system. If this is the case, SIB and other stereotyped behaviors are organized without reference to the external world. Still another way of thinking about self-stimulation is that these behaviors may also involve a learned component. For instance, Green (1967) has suggested that SIB is instrumental behavior transferred from other self-stimulatory activi-

SELF-INJURIOUS BEHAVIOR

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ties and further maintained by social consequences. Similarily, Lourie (1949) speculated that head banging is maintained first by sensory feedback resulting from the hitting and then by the social consequences of the behavior. The arousal or self-stimulation interpretation of SIB is further supported by research involving primates showing that animals reared in isolation often display various types of repetitive SIB (e.g., Berkson, 1968). There are a number of conceptual and empirical problems with this position. One concerns the mechanism by which SIB is inserted into the behavioral repertoire. A homeostatic conception of SIB, in order to be theoretically meaningful, should enable one to specify the conditions under which a particular behavior pattern emerges. In this connection, constructs such as self-stimulation, arousal, and the like are often used in a conceptually circular sense. That is, the environment is assumed to be nonstimulating because SIB occurs. But, the SIB occurs because the environment is nonstimulating. One set of facts, not two, is in evidence. Only infrequently is transsituational evidence provided that permits escape from this circularity. In summary, the homeostatic explanation of SIB has common sense appeal and is supported by some research data concerning the effects of gross stimulus variations in the environment. On the other hand, the self-stimulation interpretation of SIB seems to be too general and vague, lacking the precision necessary to engineer research procedures capable of defining and differentiating the critical variables that initiate -and control the frequency and rate of repetitious selfinjury. Indeed, one may argue on logical grounds that SIB actually induces stimulus deprivation, because when engaged in these behaviors the child is generally oblivious to the normal cuing functions of the environment. B. Psychodynamic Formulations

It is not at all surprising to find that a number of efforts have been made to conceptualize SIB in terms of psychodynamic or psychoanalytic concepts. The baffling and bizarre nature of t h i s behavior together with its apparent maladaptive personal consequences makes it a good candidate for “in-depth” personality interpretations couched in such language as “guilt,” “regression,” “poor ego identity,” “displacement,” “hysteria,” and the like. Although there is an almost infinite variety of possible interpretations of SIB, in all these views the behavior is regarded as symbolic. One frequently expressed theme is that SIB stems from lack of or search for a welldeveloped sense of the “self.” For example, Bychowski (1954) proposed that the functional purpose of SIB is not to inflict harm, but rather to determine ego boundaries and to separate the self from external realities. A similar hypothesis was advanced by Creenacre (1954) who attributed these behaviors to the child’s search for body reality.

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The aggressive aspect of SIB has not escaped the attention of those with a psychoanalytic bent. Some have postulated the need for an outlet for normal aggression. When this outlet is blocked or thwarted, self-addressed aggression appears. Menninger (1938) conceptualized SIB as suicidal behavior functioning as displacement for anger directed toward others. In addition, SIB serves to atone for real or imagined guilt, according to Menninger. Others have suggested that the inability to distinguish the self from the external world produces inward expression of aggression. Zuk (1960) speculated that SIB results from a regression of the ego identity. Thus, the body becomes nothing more than an object in the individual‘s environment, the nearest and most convenient object to which to direct expressions of anger and frustration. Others have emphasized the autoerotic function of SIB (e.g., Lester, 1972; Levy &Patrick, 1928). And so it goes. A number of analysts, noting the relatively high incidence of SIB among children who have been placed and reared under relatively nonstimulating circumstances, have suggested that SIB results from disruptions of normal mother-child interactions (e.g., Bender & Harnell, 1941; Ribble, 1943; Spitz, 1946). The mother supposedly provides the child with opportunities to express anger and to have motor outlets. Some have viewed SIB as a symbolic attack upon the mother. Others have suggested that SIB is an expression of depression, anxiety, or frustration due to the mother’s absence or negligence. In this sense, SIB may be a result of a lack of the maternal milk of human kindness. In terms of mother-child interactions, one of the more interesting accounts of the head-banging variant of SIB has been proposed by Fitzherbert (1950) who suggested that head banging results from a desire on the part of the child to match the tempo of the mother’s heartbeat which he experienced while being fed. As a corollary of this theory Fitzherbert predicted that breast-fed children should exhibit less head banging than non-breast-fed children. If this is true, then SIB may be attributable to a lack of a maternal kind of human milkness. There is some general experimental support for the notion that SIB occurs in instances where normal parent-child interactions are disrupted, Along these lines, a fairly well-established finding is that early isolation rearing of chimps and monkeys often produces SIB and other stereotyped movements (e.g., Davenport, Menzel, & Rogers, 1966; Levinson, 1970). There seems to be a critical period during which the absence of the mother produces head banging and other stereotyped movements in the infant. Separation beyond this period does not produce such critical consequences. But, in the main, the psychodynamic interpretations of SIB amount to little more than unsubstantiated speculation. Indeed, it is difficult to take some of these accounts seriously. Where treatment has been initiated in an effort to correct the presumed underlying character disorder, the results have been notably unsuccessful (Bachman, 1972). In fact, in some cases, “supportive

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techniques,” such as reassuring the individual, have been observed to increase the frequency of SIB (Lovaas, Freitag, Gold, & Kassorla, 1965; Lovaas & Simmons, 1969). C. Organic Account

No formal theory, as such, purports to account for SIB in organic terms, although it is clear from some medical practices that such a view is often implicitly adopted. Given the highly stereotyped and rhythmical nature of some forms of SIB together with its compulsive and often seemingly involuntary character, it may be tempting to regard SIB as some sort of seizurelike episode, deriving from either structural or chemical defects in the brain. This view is not entirely without empirical support. For example, the injection of chemical agents (pemoline, caffeine) has been associated with the appearance of SIB in rodents (Cenovese, Napoli, & Bolego-Zonta, 1969; Peters, 1967). SIB has been observed in decerebrate cats and in monkeys with temporal lobe lesions (Lester, 1972).

In addition, there is clearly a negative correlation between IQ and frequency and/or severity of SIB. It is at the lower IQ levels, where the probability of organic involvement is particularly high, that self-injurious and other types of stereotyped movements occur most frequently and in their most severe forms. It has also been suggested that patients who have severe neuropathology are less sensitive to pain and are, therefore, less aware that they are inflicting damage upon themselves. There is very little evidence to support this view, however. Our own experience suggests that, in fact, it is not true. At least two medical syndromes have been described which characteristically involve SIB. The Lesch-Nyhan syndrome is a sex-linked metabolic disorder in which patients typically are observed to bite their tongues, lips, and fingers. In these cases, SIB appears to be compulsive and uncontrollable. Another syndrome, Cornelia-DeLange, also has been described as involving SIB (Bryson, Sakati, Nyhan, & Fish, 1971). The form and intensity of the SIB varies considerably between patients and tends to lack the compulsivity apparent in the Lesch-Nyhan syndrome. We cannot, in short, rule out the possibility that lesions in the central nervous system are related to the occurrence of SIB. Indeed, there is some sparce evidence that supports the view. On the other hand, given the wide diversity of individual and situational conditions under which these behaviors appear, together with the obvious variability in the behavior itself, the organic explanation, in order to be considered a major explanatory position, would have to be very broad and general-perhaps too general to be very meaningful. One would have to invoke the broad concept of organicity without respect to the site or timing of the lesion or the type or extensiveness of the damage. Moreover, there

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are clearly environmental factors that must be taken into account, no matter what the CNS involvement. Certainly, there is little in the organic view that, at the present, suggests means for effective intervention. D. Developmental Interpretations

The frequency with which various kinds of stereotyped movements, including SIB, are observed among infants suggests that these behaviors may reflect the operation of normal developmental stages and maturational processes and, in fact, may serve adaptative functions. Earlier we presented evidence showing that the behavioral manifestations are not uncommon among normal infants, at least up to about 36 months. Lourie (1949), in reporting that about 20% of his pediatric cases exhibited some form of SIB, concluded that these may be normal activities that accelerate motor and personality development. Because the severely retarded are inferior in both motility and ability to adjust adaptively, stereotyped movements are not replaced by more adaptive response mechanisms. Thus, retarded individuals fail to outgrow behaviors that at one point in development serve adaptive functions. Piaget’s concepts of prima?y and secondaty circular reactions may be applied to the development of stereotyped movements. In Piagetian terms, Stage 11 of the sensorimotor phase (1-4 months) is characterized by the appearance of repetitive actions which are primarily centered around the infant’s own body (e.g., staring at hands). A subsequent secondary reaction normally develops from about 4 to 9 months during which the child repetitively manipulates external objects. Piaget has described some of these behaviors as “superstitious.” But these seem to represent normally occurring stages of growth that are important for the development of high-order motor and cognitive activities. Through some disruption of the normal sequencing, whether due to inappropriate learning experiences, the absence of critical stimuli, the lack of adequate models, or physical disability, some children become “fmted” at the level of these primary and secondary circular reactions. A generally similar view, but couched in very different terminology, was expressed some years ago by Gesell and Amatruda (1947). E. Setf-Injurious Behavior as Learned Behavior

Of the various efforts to explain SIB the most recent and, perhaps, currently most popular center on principles of instrumental conditioning. Within this view the initiating and maintaining conditions for SIB are determined by contingent relationships between the environment, the behavior, and the consequences of the behavior. Learning theory, by far, offers the most explicit (and testable) hypotheses concerning the origin and maintenance of SIB.Furthermore, it is the

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application of learning principles that has proven to be the only consistently useful procedure for the modification of these behaviors. Actually, there are two fairly distinct approaches to the explanation of SIB on the basis of learning variables: (1) the avoidance hypothesis and (2) the discriminativestimulus hypothesis (Bachman, 1972). Both were originally suggested by Skinner (1953). 1. AVOIDANCE LEARNING

Skinner proposed that self-injury may function as a response mechanism by which the organism might avoid more aversive events including conditioned fear responses. According to this view, stimuli that are associated with the presentation of an aversive stimulus develop conditioned aversive properties. Extended exposure to these conditioned events may be more aversive to the individual than the nominal aversive stimulus. The anxiety or fear responses associated with continued exposure to the conditioned aversive stimulus is thus reduced by self-punishment if such behavior results in avoidance or escape. Along similar lines, Bucher and Lovaas (1968) suggested that cues associated with punishing stimuli develop conditioned aversive properties capable of eliciting “emotional” responses, as well as escape and avoidance reactions. Tangential support of a correlational nature for the avoidance interpretation of SIB was reported by Green (1968), who found a significant relationship between physical abuse in the first 2 years of life and later head-banging behavior in schizophrenic children. One may hypothesize that some of these children may have avoided parental abuse by hitting themselves. Fear and avoidance of fear-producing situations may be a powerful variable controlling SIB. Self-injuring individuals often exhibit high rates of SIB upon release from restraints or when exposed to social contact (Bucher 8c Lovaas, 1968; Corte, Wolf, t Locke, 1971; Peterson & Peterson, 1968; Tate, 1972; Tate & Baroff, 1966). Tate (1972) reported that upon release from restraints a young female subject would appear “frightened” and perform “emotional” behaviors including SIB until the restraints were replaced. This is not at all an uncommon phenomenon. In fact, the authors have observed cases in which the patient will attempt to retie restraints from which he has been released. It is possible to imagine situations in which a retarded or autistic individual could avoid or escape from unpleasant situations by performing SIB. On initial reflection it may seem strange that an individual would resort to such extreme measures to escape or avoid other unpleasant conditions. Yet, the extreme character of this behavior may make it particularly adaptive as an avoidance behavior, because adults find it difficult to ignore. In addition, the behavioral repertoire of many of these individuals is very limited. Moreover, cues associated with the unpleasant situation would become conditioned aversive stimuli capable of eliciting escape or avoidance behavior, including SIB. SIB would thus be reinforced by the escape from or avoidance of “aversive” situations. An expla-

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nation of this nature could account for a phenomenon reported by Rollings, Baumeister, and Baumeister (in press). They observed that the application of mild punishment procedures (overcorrection) to suppress stereotypic body rocking exhibited by a male retardate was associated with markedly increased self-hitting early in training. However, the rate of SIB decreased with extended training suggesting extinction of self-hitting in the training environment. Self-hitting may have occurred during treatment because SIB had been successful in avoiding or escaping from unpleasant situations in the past. The self-hitting then extinguished in the training environment because it was ineffective in preventing escape from the aversive situation. These interpretations, of course, are merely suggestive. There is more direct experimental evidence that punishment can facilitate and maintain behavior. One of the most compelling studies for an avoidance interpretation was reported by Bandura (1969) who described unpublished research by Sandler and Quagliano which directly demonstrated such avoidance behavior with monkeys. In effect, they were able to simulate “masochistic” behavior through an avoidance conditioning paradigm. Subsequent to avoidance training, in which shock was averted by lever pressing, a shock of lesser magnitude was made contingent upon the avoidance response. The animal was caught between two “evils.” He could only avoid the more painful shock by administering a less painful shock to himself. The magnitude of the contingent shocks was gradually increased to the level of the avoided shock but with no concomitant deceleration of avoidance responding. Furthermore, punished responding continued after the avoidance contingency was terminated and no shock was delivered for failure to avoid. The nature of the avoidance conditioning paradigm is that it does not usually lead to rapid extinction of the avoidance behavior, because the subject is not apt to “take the chance.” This study clearly shows that the conditions under which a stimulus is presented are important in predicting its subsequent effects on behavior. Several other investigators have systematically demonstrated that punishment of avoidance and escape responding is capable of maintaining such behavior in animals (Bender, 1969; Brown, Martin, & Morrow, 1964; Rollings & Melvin, 1970; Sandler & Davidson, 1971). This seemingly maladaptive behavior is sometimes referred to as the “vicious circle effect .” Sandler and Davidson (197 1) observed that subjects with long avoidance-training histories would continue the avoidance response learned initially, even though that response was later punished with strong shock and even though an alternate nonpunished response was available. Similar effects have been experimentally produced with retarded subjects. Corte et al. (1971) reported that the use of mild shock contingent upon the SIB exhibited by a retarded female subject was associated with “markedly” increased rates of SIB, again suggesting that children may engage in the SIB to avert other stimuli.

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The facilitation of SIB under conditions of mild punishment poses some theoretical questions. Is the facilitation of SIB with mild shock related to the same processes which maintain avoidance responding under conditions of punishment (e.g., Sandler & Davidson, 1971)? Can SIB be shaped and maintained by escape under controlled experimental conditions? Can SIB be brought under the control of highly discriminated stimuli? 2. DISCRIMINATIVE FUNCTION

One of the most perplexing aspects of SIB is the failure of the apparently painful self-injurious responses (e.g., pulling the fingernails out by their roots, head banging) to suppress further self-injury. Skinner (1953) suggested that an aversive stimulus could function as a conditioned positive reinforcer if contingencies were such that the aversive stimulus was selectively associated with or predicted positive reinforcement. Thus, the aversive stimulus (possibly the pain) may be discriminative for subsequent positive reinforcement. This “cue” theory essentially describes a situation in which the retarded individual can learn to identify stimuli that reliably signal either reward or punishment. In the process the aversive event itself may become positively reinforcing. In fact, we offer the generalization that given the appropriate conditions, any stimulus can become a positive conditioned reinforcer. Moreover, if the “training” were accomplished through intermittent schedules of reinforcement, then we should expect the behavior to be maintained over long periods of time without additional reinforcement. Expressly dealing with the problem of SIB in children, Lovaas and Simmons (1969) speculated that the pain associated with self-injurious responding could become discriminative for the social reinforcers that presumably follow SIB. Lovaas et a2. (1965) had previously demonstrated that contingent social reinforcers in the form of adult attention effectively increased the rate of SIB in a psychotic girl. Furthermore, Lovaas and Simmons (1969) reported that adult attention contingent upon SIB was associated with increased self-injurious responding compared to a previous condition in which no attention was given. Ample experimental evidence exists for the view that nominally punishing stimuli can also function as discriminative cues. The discriminative properties of punishment have been reliably demonstrated in pigeons (Holz & Azrin, 1961), monkeys (Sandler, 1962), and in humans (Ayllon & Azrin, 1966). Ayllon and Azrin established discriminative and conditioned properties of an aversive noise with chronic schizophrenic females. The aversive properties of the noise were first demonstrated in a conventional two-response operant situation. Subsequently, when the noise was associated with positive reinforcement (tokens), the subjects responded to produce the noise. Finally, a new response (button pushing) was shaped utilizing noise alone as the reinforcer.

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Obviously, it is necessary to examine the reinforcement history of the subject, including his experience with both positive and negative stimuli, in the analysis of the etiology of SIB (Sandler & Davidson, 1971). The discriminative stimulus hypothesis of SIB takes into account the stimulus properties of the behavior (SIB) and its relation to the system of rewards and punishers that function in the environment of the individual. Many instances of SIB occur within the context of specific environmental events (Bachman, 1972). For example, release from restraints has been shown to be discriminative for the occurrence of SIB (Bucher & Lovaas, 1968; Corte et aL , 1971; Lovaas & Simmons, 1969; Tate, 1972; Tate & Baroff, 1966; Thomas & Howard, 1971;Yeakel, Salisbury, Greer, & Marcus, 1970). Thomas and Howard (1971) reported that upon release from restraints a retarded male subject would immediately engage in SIB (head banging and face hitting). Similarly, Yeakel et aL (1970) observed that a female autistic child would immediately begin hitting her head subsequent to the removal of shock electrodes from her arm. Peterson and Peterson (1968) reported that the withdrawal of the favorite blanket of a young retarded male subject was associated with increased SIB (head banging, self-hitting) relative to periods when the blanket was in the cbild’s possession. Possibly the blanket functioned as a powerful reinforcer for the subject and that removal of the blanket became discriminative for SIB. Likewise, Lovaas et aL (1965) demonstrated that the withdrawal of social reinforcers (praise) from a previously reinforced response (appropriate music behaviors) was discriminative for SIB (e.g., head banging, self-hitting) in a young schizophrenic girl. Additionally, the extinction of another socially reinforced response (bar pressing) was associated with increased SIB relative to the acquisition of the bar-pressing response. Lovaas and his associates suggested that the SIB as well as the appropriate music and bar-pressing behaviors were maintained by social reward. Extinction of the previously reinforced behavior (bar pressing, music behaviors) became the discriminative stimulus for other behaviors (SIB) which were also under the control of social reinforcers. The subject exhausted her repertoire of socially reinforced behaviors according to a hierarchy. The most recently learned behaviors (e.g., bar pressing) extinguished first followed by behaviors which were well established in the response hierarchy. Thus, when bar pressing and appropriate music behaviors were extinguished, the subject performed behaviors (SIB) successful in obtaining social reward in the past. Procedures designed to suppress stereotyped behaviors have been observed, on occasion, to cause an increase in occurrence of SIB. For example, J. C. White and Taylor (1967) noted the occurrence of SIB (arm biting) when shock procedures were utilized to suppress rumination and vomiting behaviors exhibited by young retarded females. Rollings et al. (in press) found that the application of overcorrection procedures to suppress stereotypic head weaving exhibited by a severely retarded male subject was associated with the Occurrence of

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SIB (self-pinching, self-scratching, head banging). Furthermore, the use of overcorrection procedures to eliminate high-rate rocking behavior of another subject was associated with increased self-hitting behavior. The suppression of certain high-rate stereotyped behaviors may become discriminative for other forms of stereotypic responding including SIB. Moreover, these can be very fine discriminations. In a more tightly conducted study Rollings (1975) demonstrated that self-hitting could be brought under control of visual stimuli. Following baseline procedures, a multiple schedule of punishment was utilized to train retarded subjects to discriminate lights arranged linearly on a stimulus panel directly ip front of the subject. Two of the lights, located on either end of the stimulus panel, served as training stimuli and the remainder functioned as test stimuli. During presentation of the “punishment stimulus” (one or the other end lights) target stereotypies were punished by overcorrection procedures. No contingencies were in effect during presentation of the “safe” stimuli (the remaining lights). Subsequent to discrimination training all of the test and training stimuli were presented in extinction. “‘he essential question concerned the extent to which the subject could form discriminations between the end lights (signaling punishment for the stereotypy) and the middle lights (signaling that it was “safe” to engage in the stereotypy). Steep gradients of inhibition were obtained for the target stereotypies with minimum stereotyped responding at test values in close spatial proximity to the “punishment” stimulus. The further the test stimulus from the punishment stimulus, the greater the rate of stereotyped responding. Furthermore, nontarget stereotypies, including SIB, also appeared to be under stimulus control. Orderly gradients were obtained for these behaviors under test conditions. The gradients for the collateral behaviors were the inverse of gradients observed for the target stereotypies, with greater SIB exhibited during presentations of “punishment” stimuli relative to “safe” correlated stimuli. In addition, the same trend was recorded during the discrimination training phase of the experiment. The situational nature of SIB has also been demonstrated in primates. Levinson (1970) noted that head banging of a young rhesus monkey appeared with “aversive” events such as termination of handling by the trainer. The finding that self-injurious responding often occurs under tight environmental control offers strong support for the avoidance and discriminative stimulus accounts of SIB. Whether SIB is an avoidance behavior or a socially reinforced behavior or still another class of behavior is an issue that requires further study utilizing rigid experimental procedures. It is conceivable that SIB may actually serve both avoidance and discriminative functions. For example, selfinjurious responding may function as an attention-getting device under certain conditions of social deprivation. Additionally, SIB may serve to avoid certain events (e.g., participation in training situations) which may be aversive to the individual.

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In attempting to differentiate among the various theoretical perspectives regarding SIB, we have not made a fine or precise distinction between conditions from which the behaviors originate and those conditions that maintain the behavior. Indeed, the genesis of the behavior may be quite a different matter from the maintenance of the behavior. We believe this to be the case, particularly with respect to the role of learning. To put it simply, we are not at all sure what caused the behavior in the first place, but we are willing to state that in most cases the behavior is maintained by instrumental conditioning. Furthermore, the very fact that one can decelerate these behaviors by arranging contingencies certainly does not prove that either the avoidance conditioning or the discriminative stimulus theories is correct.

111. MODIFICATION OF SELF-INJURIOUS BEHAVIOR

The most common method of controlling SIB, particularly in institutional settings, is to restrain the subject totally or partially. Instances are not uncommon in which an individual is physically restrained virtually all day and night. In some cases that involve biting, teeth have been extracted. Tranquilizing drugs are often administered, sometimes in amounts that might appropriately be called “chemical restraints.” In regard to drug therapy with SIB, Butteworth and Bower (1959) have reported that sedation with tranquilizing drugs “is useful.” This is not the typical conclusion regarding drug therapy, however. A more representative conclusion was that of Berkson (1965) who found that neither amphetamines nor barbiturates, except in sufficient amounts to induce sleep, had any effect upon head or torso banging. Furthermore, Maisto and Baumeister (1975) reported that tranquilizing drugs were found to be generally ineffective in the treatment of SIB exhibited by residents of a state institution. While these restraint methods are effective for temporarily inhibiting SIB, they obviously are not very satisfactory in the long run. Furthermore, they tend to impede the development of more functional adaptations. In fact, there is some evidence to suggest that rates of SIB are often significantly higher during postrestraint as compared with prerestraint measures. A number of workers have noted that the application of restraints may in itself possess reinforcing properties (e.g., Tate, 1972). Moreover, restraints clearly take the subject out of the learning situation. In those few instances where “supportive” intervention techniques (i.e., expressing feeling, attending to the behavior by interpreting it, and generally exhibiting concern) have been attempted, the results have not proven to be very encouraging. Some have suggested that “tenderness” may decrease SIB (Spock, 1945). But these observations are mainly anecdotal in nature and not supported by experimental research. Indeed, given the reasonable possibility that at least some SIB is frequently controlled by social consequences, we might expect to

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observe an increase, rather than a decrease, in rates and/or intensity of SIB if social reinforcement of any nature is made contingent upon the behavior. The only intervention procedures that seem to produce positive results fairly consistently are those based on instrumental learning principles. A considerable literature, much of it the case report variety, is now beginning to accumulate showing that the techniques of behavior modification are useful in controlling the rates and intensity of SIB. A variety of different procedures have been reported, each more or less tailored to the specific instances, rates, and frequencies of SIBS exhibited by a particular individual. However, it is possible to categorize these methods in terms of their major contingencies: (1) differential reinforcement of other behavior, (2) removal of positive reinforcement, and (3) punishment. A Differential Reinforcement of Alternative Behavior

In this procedure, the trainer ignores instances of the SIB and reinforces the subject for engaging in incompatible, alternative, or socially more acceptable behavior. In operant conditioning terms this is sometimes referred to as differential reinforcement of other behavior (DRO). In some cases, the “other” behavior may be the absence of the SIB. With this sort of a contingency, it is not possible to separate the effects attributable to the DRO contingency from those arising from time out from reinforcement. Another possibility is to arrange the consequences such that the child receives reinforcement only when the rate of the behavior decreases by some specified amount. This differential reinforcement of low rates (DRL) has not received much attention as a treatment for SIB. One of the fint studies in which a systematic attempt was made to manipulate the reinforcement contingencies associated with SIB was reported by Lovaas et al. (1965). They worked with a 9-year old schizophrenic child who exhibited high rates of head banging and other self-destructive behaviors. An alternate behavior, hand clapping to music, was reinforced with smiles and praises. SIB decreased to a near zero level when the alternative behavior was rewarded, but again increased dramatically when social approval for the alternative behavior was withheld. In a follow-up study with the same child another behavior, bar pressing, was reinforced with approval and attention. The results were much the same as in the first study: a decrease in SIB when the alternative was reinforced, an increase when the alternative was placed on extinction, This study may seem to accomplish the obvious-if the subject is using his hands to engage in one activity (e.g., bar pressing) he cannot use them for another (e.g., head banging) and, furthermore, we cannot reasonably expect an individual to bar press or clap all the time. Certainly the DRO contingency, applied for short periods, involving only a very restricted range of alternative

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behaviors, and carried out in highly specific and contrived situations, cannot be regarded as a meaningful educational “program” for the elimination of SIB. Other investigators have generally reported encouraging if not dramatic results with procedures in which the essential feature is the reinforcement of behaviors as alternatives to the SIB. Allen and Harris (1966) described a case in which a child who severely scratched herself was taught to engage in more socially appropriate behaviors. Suppression effects were maintained over a Qmonth period. An interesting and not irrelevant aspect of the procedure was that the therapists were the child’s parents, who conducted the program at home. Substantial control of self-biting in an 8-year-old boy was achieved by Peterson and Peterson (1968) who reinforced the child with food and verbal praise after intervals in which the SIB did not occur. Reversing the contingencies returned the SIB to high rates. Peterson and Peterson likewise note the need t o expand the behavioral repertoire in order for the DRO contingency to produce adequate generalization. Most studies in this area are not experimentally “clean” in the sense that one would like to state with reasonable certainty which effects were produced by which variables. An example of these confoundings can be found in a recent study by Repp and Deitz (1974), who combined verbal punishment, restraint, and DRO procedures in an effort to reduce self-scratching in a severely retarded girl. The child was given candy following short intervals in which the SIB did not occur. If the child scratched, the trainer said “no” and pulled the girl’s hands to her side. A timer was set and the DRO contingency was reinstated. The interval was initially 1 second but over many sessions was gradually increased to 120 minutes. This assortment of procedures was effective in eliminating the behavior. However, because of confoundings in the study it is not possible to attribute the suppression to the DRO procedure alone. Nevertheless, these and other studies involving the DRO contingency as the essential treatment feature have reasonably established that under some circumstances the SIB can be brought under temporary control (Forehand & Baumister, 1976). Generalization of SIB suppression, from one situation to another ’ and from one trainer to another, however, has not been adequately demonstrated. Whether long-term control of SIB can be maintained with this technique is also an unresolved issue. Nevertheless, with respect to the questions of both generalization and durability, we may reasonably conclude that any program that permits the reintroduction of the contingencies that either initiated or maintained the SIB will certainly produce a recovery in the rate of these behaviors. The assumption, too, that contingent reinforcement of an alternative behavior is the crucial factor accounting for deceleration of SIB is open to question. In many cases, particularly those found in institutional settings, the type and form

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of stimulation and the opportunity to engage in alternative behavior are limited. The question arises, then, simply as to what might happen if more meaningful patterns of stimulation were introduced into the environment and the range of possible alternative behaviors were increased. The specific contingencies may be less important than the opportunities for other behavior. We know from studies of other types of stereotyped movements that enrichment of the environment together with an increase in the variety of possible behaviors that the subject might emit are associated with rather marked decreases in the rates of the aberrant behavior (Baumeister & Forehand, 1973). SIB and other forms of maladaptive behavior may develop and be maintained because the child has no other behavioral opportunities available. B. Removal of Positive Reinforcement

This category of techniques involves a variety of different procedures, though all are founded on the same fundamental principle and all have essentially the same goal: (1) SIB is controlled by its consequences and (2) removal of those consequences will decrease the occurrence of SIB. Ignoring the behavior (extinction), isolation of the individual contingent on the response (time out), and response cost contingencies have all been applied more or less successfully. In some cases, withdrawal of specific positive reinforcement has been made directly contingent upon the occurrence of the SIB. However, in other studies, positive reinforcement has been withdrawn by removing the subject to a situation in which all reinforcing stimuli are supposedly absent. This latter procedure is usually governed more by “hope” than by certain knowledge of controlling events. One of the earliest, most cited, and perhaps the most thorough studies of extinction procedures was undertaken by Lovaas and Simmons (1969) who isolated two self-destructive children for 1% hours daily over a period of 17 days. They assumed that social stimuli were maintaining the SIB and that isolation, therefore, would interrupt this contingency. Over the treatment period a gradual drop in frequency of SIB was noted for both subjects, although for one child several thousand responses were recorded, indicating that extinction may take a very long time. A similar procedure was employed by Miron and Rooney (1973) working with two children who exhibited high rates of SIB. In this instance, the children were removed from isolation when the behavior did not occur for a 1-minute period. Again, both subjects showed a gradual decrease in their SIB over treatment sessions. However, the effect was transitory, a finding that others have also reported. Although it is often assumed that aversive physical punishment produces quicker, more specific, and more durable response suppression than simple noncontingent social isolation, this is not always the case. After failing to

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eliminate self-hitting by a 9-year-old girl using response-contingent shock, Jones, Simmons, and Frankel (1974) isolated the girl for 1 hour in the morning and 1 hour in the afternoon, periods in which she was free of restraints. During the first week of isolation she hit herself approximately 34,000 times. By week 17 the behavior dropped out completely. There was, however, subsequent recovery in response rate requiring reintroduction of the isolation procedure. A number of additional observations were made by Jones, Simmons, and Frankel that are notable. They reported that the girl exhibited two topographically different forms of self-abuse and these were functionally interchangeable in that as one increased the other decreased. Alternate behaviors of this nature may either be under the control of the same discriminative stimuli or they may produce equivalent consequences. These are points to which we shall return subsequently. Treatment methods that specifically target one form of behavior may produce an increase in another. In the study by Jones et al. noncontingent isolation presumably disrupted the controlling stimuli for both forms of SIB. In addition, a variety of positive side effects, mostly involving improved social interaction and self-feeding, were observed. Another point raised by Jones et al. is that restraints previously worn by the child may have acquired stimulus control. Initially, the child seemed to behave as if the restraints were reinforcing, even asking for them when they were removed. Other investigators have observed this phenomenon with sufficient regularity to require us to account for it both theoretically and therapeutically. On the theoretical side, it is possible that the restraints acquire reinforcing properties that arise out of the social relationships that occur when the restraints are put on. On the other hand, the restraints may be associated with nonpunishment, assuming that either the self-abuse does carry with it some aversive properties for the child or that other methods for treating SIB (e.g., shock) are aversive. Restraints, thus, may become discriminative for “safe” periods. From the therapeutic standpoint, isolation may produce its effects because of extinction of the stimulus control exerted by the restraints. In contrasting the extinction procedures used by those who have reported positive results (e.g., Ferster, 1961; Lovaas & Simmons, 1969) with those who have reported failure (e.g., Bucher & Lovaas, 1968; Corte et al., 1971), the outstanding difference lies in the length and number of isolation sessions. Virtually all the studies we have reviewed indicate that, in most cases, extinction produces response suppression only gradually over a long period of time. The trainer must be prepared to accept high rates of SIB in his clients at least during the initial stages of the treatment. One may conclude, on the basis of these studies, that noncontingent removal of reinforcement procedures is very slow in its effects and does not inevitably produce stable decrements in rates of SIB. The most obvious disadvantage of such a procedure is that the individual is allowed to continue to abuse himself

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during the isolation periods-consequences that may be unacceptable in particularly severe cases. Isolation, applied contingently as time out from social reinforcement, may produce more satisfactory results. The main distinguishing feature of this procedure is that it represents a period of time in which positive reinforcement is not possible, the time-out period being made contingent upon the target behavior. Time out probably functions as a mild aversive stimulus (Willoughby, 1969). Most studies utilizing time-out procedures to suppress SIB involve a combination of time-out and DRO escape contingencies, i.e., the individual must refrain from SIB for a certain duration in order to “escape” time out. The first systematic application of this procedure to SIB was made by Wolf, Risely, and Mees (1964) who were able to eliminate head banging and face slapping by an autistic child. A follow-up study with the same child some time later in a different setting showed that the isolation contingency was transferable. Using similar procedures, Hamilton, Stephens, and Allen (1967) eliminated high-rate head banging of a severely retarded female by restraining her in a padded chair in an isolation area. Time-out periods ranged from 30 minutes to 2 hours. Suppression of the SIB endured over a 5-month interval. The question arises as to how long the optimal period for time out may be. There are a number of considerations involved in answering this question, not the least of which are the nature, intensity, frequency, and topography of the target behavior itself. But, as we have already noted, extremely long periods of time out may be contraindicated because they limit opportunities for the child to emit adaptive behavior. Also, there is an ethical problem here in that it is unconscionable to expose a child to time-out periods that exceed their effective durations. In general, investigators have used time-out periods ranging from 5 to 30 minutes, although there are some marked exceptions in either direction. Occasionally procedures are applied in which the subject is placed in time out until the inappropriate behavior ceases. One study of the duration variable has been reported in which acts of self-destruction were involved. White, Nielsen, and Johnson (1972) compared the effectiveness of time-out periods of 1, 15, and 30 minutes. Results with the 1-minute period were generally not as satisfactory as those of 15- or 30-minute durations, which were about equally effective. Although the 1-minute period did produce some deceleration of the target behaviors, it was also clear that very brief periods of time out were not stable in their aversive properties. We should, however, also stress that a critical variable governing the effectiveness of time out is the schedule with which it is applied. As a general principle it is probably better to punish every deviant response with a relatively short time-out period than to consequate long periods which, in effect, produce greater intermittency of reinforcement.

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One study has been reported in which a specific response cost contingency has been applied to SIB. Tate and Baroff (1966), having observed that physical contact was reinforcing to a child who engaged in SIB, withdrew hand holding for a 3.second period each time the child engaged in head banging and face slapping. These behaviors were virtually eliminated by this time-out procedure. A number of investigators have noted the appearance of some beneficial side effects from procedures that involve withdrawal of positive reinforcement for SIB. Among the concomitant behaviors that have been reported are increased eye contact, increased social interactions, and the deceleration of other undesirable behaviors. On the other hand, some practical limitations associated with these procedures should be mentioned. For one, the SIB is free to occur, the consequences of which may be serious. Second, control over the behaviors is slowly achieved and, in some instances, in fact, an increase in rate or intensity may be observed. Perhaps the most serious disadvantage from an educative point of view is that any kind of time out removes the subject from a learning situation. Of course, the longer the time-out interval, the more serious this problem becomes. Finally, the suppression effects seem to be highly situationspecific, particularly with respect to noncontingent isolation. Generalization typically does not occur spontaneously and must be deliberately and systematically programmed. C. Physical Punishment

Perhaps the most popular method for suppressing SIB is application of a strong aversive stimulus immediately contingent upon the response. Electric shock has been used more frequently than other types of noxious stimuli. The chief advantages of electric shock are that it can be applied quickly, for precise periods of time, and over a wide range of intensities. Moreover, inasmuch as human subjects do not readily habituate to shock, it retains its reinforcing properties. Although contingent electric shock probably has wide application in regard to SIB, most of the published literature concerning its effects are of the singlesubject case study variety. The primary motivation for these studies, quite understandably, is to control SIB rather than to study the effects of shock in a systematic and experimental manner. Because of this emphasis, however, it is difficult to arrive at many fum conclusions concerning the conditions under which shock might be effective. These case reports represent something less than elegant research. In this regard, too, the literature may be especially biased in the positive direction. That is, investigators who have applied electric shock to SIB may be less inclined to publish their cases when the therapeutic results are unfavorable. In one of the first published reports utilizing response-contingent electric shock, Tate and Baroff (1966) were able to eliminate head banging and face

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slappingin an autistic child. During the initial baseline period SIB occurred at the rate of 5 responses per minute. After just one treatment session the behavior dropped off almost entirely. Although rarely employed, these procedures were followed for 167 days, the last 20 of which there was no occurrence of SIB. A number of other investigators have reported similar results with contingent shock. The inhibiting effects of shock on SIB seem to be highly durable. On the other hand, the evidence also suggests that subjects are capable of making sharp discriminations with respect to the shock contingency. Lovaas and Simmons (1969) were able to eliminate high-frequency SIB in three children by contingently shocking them. However, suppression of the behavior was limited to the physical setting in which the shock was administered and to the trainer. Little or no generalization occurred across situations or persons, a finding which has been confirmed by others (Forehand & Baumeister, 1976; Miron & Roonery, 1973; Smolev, 1971). A variety of positive side effects, such as increased attention, also have been reported concerning the use of shock. Collateral behavior changes of this nature may result from a conditioning history in which the child has learned to avoid aversive consequences by attending to adults. Another possibility is that once the deviant behavior is eliminated the child is exposed to another set of contingencies that reinforce desirable behaviors. One particular advantage to the use of shock is that it readily lends itself to the development of conditioned aversive stimuli. For example, Lovaas and Simmons paired the word “no” with the shock and found that the word itself came to elicit avoidance behavior. Others have also used this conditioning paradigm. Another advantage is that the principles are easy to communicate. If the procedure is going to work at all, the results are usually immediate and apparent. Parents and others not versed in the methods of behavior modification can readily be taught how to apply the shock contingency. Several efforts along these lines, with teachers and parents as trainers, have been reported (Merbaum, 1973; Risley, 1968; Wright, 1973). Taken as a whole, the case report literature in which electric shock is used as a contingent aversive stimulus indicates that it is an effective, probably the most effective, method for controlling SIB. Suppression effects are immediate and durable. The emergence of positive collateral behaviors has often been observed. The procedure lends itself well to the avoidance conditioning paradigm. The main limitation (aside from ethical issues concerning social acceptability) seems to be that suppression effects are highly specific to the training situation. This appears to be primarily a procedural problem in that generalization of suppression can be accomplished by systematically fading stimuli and altering trainers as Lovaas and his associates have done. There is another consideration that should be raised in regard to any conclusions about the effectiveness of aversive control of SIB. Most of the reported studies are not sufficiently analytical to permit conclusions concerning the

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actual contingencies in effect. That is, an electric shock may have suppressive properties if administered at any point, before, during, or after the response sequence. The obvious control condition, one in which shock is administered in a random or noncontingent manner, has not, with one exception, been included as a part of the experimental design in these various studies. In a recently reported study, Bachman and Wincze (1975) found that the noncontingent shocks did quickly suppress SIB in two subjects, although at low rates of presentation these effects were not maintained. Punishment may suppress behavior, not necessarily through avoidance learning, but rather because aversive stimulation contributes to general arousal level. Such an interpretation is, of course, consistent with the homeostatic theory of SIB discussed earlier. In many cases, it has been reported that there is a general increased attentiveness following punishment. This observation is also consistent with the arousalself-stimulation hypothesis. However, a study explicitly designed to test this hypothesis (Kohlenberg et al., 1973) failed to show any significant changes in arousal (as measured by skin conductance) following contingent electric shock, although SIB was decelerated by this procedure. On the other hand, the arousal hypothesis could be wrong. Electric shock, obviously, is not the only aversive physical consequence that can be applied subsequent to the behavior. A variety of stimuli, including loud noise (Sajwaj & Hedges, 1971), noxious odors (Tanner & Zeiler, 1975), hair pulling (Banks & Locke, 1966), restraint (Saposnek & Watson, 1974), slapping (Bucher & Lovaas, 1968), overcorrection (Foxx & Azrin, 1973), and even tickling (Greene & Hoats, 1971) have been reported to produce response suppression of SIB. None of these alternatives, with the possible exception of noxious odors and the overcorrection procedure, discussed in some detail below, appears to be as effective as shock. Responsivity varies with intensity of the aversive event and with the individual subject. The use of aromatic ammonia as an aversive stimulus contingent upon face slapping in a 20-year-old woman has been reported by Tanner and Zeiler (1975). They held a crushed capsule of ammonia under the subject’s nose until she ceased to slap herself. Suppression of face slapping was immediate and virtually complete. Generalization of these effects, however, was not particularly impressive possibly due to lack of adequate follow-through on the part of ward personnel. Clearly, when using ammonia capsules, care should be exercised to prevent contact with skin and irritation of the nasal mucosa. On the other hand, this procedure has some of the same advantages as electric shock. Moreover, no special instrument is required, thus preventing the subject from malung a discrimination on the basis of the presence or absence of a shock prod. Recently another more complicated procedure termed “rage reduction” has been described by Saposnek and Watson (1974). Although this procedure consists of a variety of distinct operations, one of its essential features seems to

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be that it incorporates a mild aversive component. The trainer holds the child in his lap and by blocking the child’s arms actively prevents him from striking or gouging himself. At the same time the child is urged or forced to hit the trainer’s hand. Saposnek and Watson report one case in which head slapping was reduced from a rate as high as 85 responses per ’A minute, to a rate of only 1 or 2 responses per week. As good as this technique may sound there are practical limitations in its application. Aside from the fact that there are some data which suggest that physical restraint may actually aggravate stereotyped behavior (e.g., Forehand & Baumeister, 1970), the rage reduction technique is not very practical in that it requires a considerable amount of staff time and is very slow to bring the behavior under control. The rage reduction treatment is similar in some ways to another new procedure that has recently been receiving a great deal of attention. This is the “overcorrection” principle originally introduced by Foxx and Azrin (1973) and extensively applied by Azrin and his co-workers. Actually, there are two main forms of overcorrection: restitution and positive practice. The former is not relevant to this discussion because it is applied in those instances where the individual engages in behaviors that have a destructive or disruptive effect on the environment. It is in those instances involving abuse to the self where positive practice is applied. This procedure requires to the subject to practice correct forms of some alternative and more adaptive behavior. This variation of overcorrection supposedly suppresses SIB by a combination of practice of incompatible behavior while at the same time extinguishing the undesirable behavior. A variant of the overcorrection procedure is that which Azrin and his group call “required relaxation,” in which the overcorrective procedure requires the subject to practice being calm and relaxed. Although, again, these rather complicated procedures incorporate a variety of chained contingencies, they do appear to involve, as Foxx and Azrin have suggested, a “mild-punishment.” Azrin and his associates have published a number of papers describing the overcorrection procedure in detail and, generally, the results of their studies in which they have treated various kinds of stereotyped behaviors are rather remarkable. For example, Webster and Azrin (1973) described a number of cases, one involving rather severe SIB, in which almost complete suppression of the behavior was achieved by the fifth day of training. A survey made of ward staff revealed that they favored this procedure over other methods as more humane and effective. In another paper Azrin, Gotlieb, Hugart, Wesolowski, and Rain (1975) reported their attempts to treat 11 cases of SIB, with results that were quite astonishing. The average reduction in the rate of SIB by the first day was 90%. By the seventh day a reduction of 96% had been achieved. Moreover, with the exception of one subject, a general improvement was observed in other areas of functioning, primarily involving increased social responsiveness. Some positive response generalization of this nature following overcorrection of stereo-

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typed movements was also reported by Epstein, Doke, Sajwaj, Sorrell, and Rimmer (1974). They also observed at least one instance of undesirable collateral responding. Reports concerning the impressive results of the overcorrection principle notwithstanding, there are a number of questions concerning the procedure that remain to be answered. Forehand and Baumeister (1976) have discussed some of these problems in detail, and we shall only highlight them here. For one, overcorrection procedures do not always produce marked reductions in rates of the target behavior (eg., Rollings et al., in press). Second, overcorrection involves so many components, including extinction, time out from positive reinforcement, restraint, prompting, reinforcement of competing responses, alterations in the social environment, and others, that it is difficult to ascertain which factors or combinations of factors produce behavioral changes. Third, there is evidence that undesirable collateral responding may occur (e.g., Rollings, 1975). Fourth, durability and stimulus generalization effects have not been adequately demonstrated. Indeed, in regard to the latter point, our own research suggests that response suppression is limited to the context in which the training occurs. Finally, one may question the feasibility of overcorrection for SIB in view of the rather marked and substantial effects produced by electric shock.

D. Collateral Behaviors and Symptom Substitution Most of the literature which makes reference to the side effects of procedures designed to suppress SIB suggests that these effects are generally of a positive nature. Typically observed are increased sociability, eye contact, and cooperativeness. A number of explanations have been offered to account for these beneficial side effects including inadvertant punishment of nontargeted behaviors, punishment of the target which is part of a chain of responses, and punishment of a functionally determined class of behaviors. Parenthetically, one may question just how generally adaptive such behaviors as increased attention and eye contact are in this context. Certainly a person who has been on the business end of a shock wand may be highly attentive to anyone who is carrying one around. Of course, most of these reports are of an anecdotal nature in that =liable pre- and postmeasures of these “new” behaviors have not typically been systematically carried out. Moreover, there may be a tendency on the part of the trainer to look for the good outcomes and to ignore the bad. Finally, editors are usually far more favorably disposed to positive results than to negative ones, especially when procedures are involved that are not universally acceptable in a social sense. Nevertheless, a sufficient number of trustworthy reports have appeared indicating that punishment procedures, in particular, may generate a variety of undesirable side effects. For example, Napolitan and Peterson (1975) found

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that, in treating selected SIB, increases were observed in other nontreated self-abusive behavior. Furthermore, they reported a general increase in preexisting stereotypies and, more alarmingly, the development of new stereotypies. A highly similar situation was described by Rollings et ul. (in press). Lovaas and Simmons (1969) successfully suppressed SIB in a single session,only to find an increase in aggressive acts by their subject. A child treated by Tate (1972) began to exhibit hand waving and, for a time, refused to eat. The development of collateral behaviors of an undesirable nature is clearly a problem of sufficient seriousness and magnitude to warrant consideration from a therapeutic point of view. Moreover, the appearance or increase in rate or intensity of collateral behaviors, both good and bad, presents some interesting and important theoretical issues. Following the lead suggested by Cahoon (1968), we shall refer to the undesirable behavioral side effects as symptom substitution. This is a term that, of course, has wide currency in the traditional psychotherapeutic approaches, particularly those of an analytical persuasion. No excess meaning is attributed to the term here. Symptom substitution, as used here, refers to the appearance of behavior that either causes problems for the individual and/or those around him. No inference is made to internal states of the individual or to “underlying causes” except insofar as these refer to objectively specifiable classes of independent variables that are part of a common set of contingencies or involve discriminative situations that apply to multiple responses. For example , a child may have learned a number of behaviors to gain adult attention. If one of these fails in a particular instance, he may then resort to another. Assuming that both behaviors are socially inappropriate, then given successful suppression of the first, the second is defined as symptom substitution. It is our view that symptom substitution, defmed in this sense, is a highly probability occurrence when one form of SIB is suppressed. Symptom substitution is something to be avoided and its potential should be considered in any treatment program. Although the specific symptoms which may appear are often unpredictable, we believe that the lack of attention on the part of the therapist to rate changes in nontargeted behavior frequently leads to the addition to or acceleration of other undesirable behavior in the repertoire. We assume that a behavior in any given stimulus context and with any given consequence is a probabilistic event. That is, the subject’s behaviors are stochastically stacked or arranged hierarchically such that with the cues available in Situation A reinforcement is predicted following Behavior B. If Behavior B fails to produce reinforcement, or when the response is in some way inhibited, then the subject emits Behavior C and so on until reinforcement is forthcoming. Behaviors are arranged in this hierarchy according to their probability of reward and punishment. Thus, if Behavior B is now predictive of punishment, then some other behavior is, in effect, rewarded through avoidance of punishment and its

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probability of occurrence thereby increased. Contingencies that serve to maintain one maladaptive behavior may come to support other undesirable responses. The order of responses in this probabilistic stack can be altered through learning. Of course, behaviors may also be “mutually inhibitory” in that performance of one may physically or functionally preclude the other (Dunham, 1972). The notion that stereotypic behaviors may be hierarchical in the response repertoire in retarded individuals has been suggested previously. For example, hvaas et al. (1965) argued that retarded individuals exhibit a hierarchy of behaviors in each environmental context and that the subject will sample his behaviors accordingly to determine which behavior will be reinforced. Taking this point further, if some of these are maladaptive behaviors, and they are all controlled by the same contingencies, then deceleration or inhibition of one will inevitably lead to an increase in rate of another, i.e., symptom substitution. This hypothesis is supported by the results of an unpublished study by Ullman and Krasner, cited by Cahoon (1968), who reported the successive elimination of a variety of maladaptive behaviors (including SIB) exhibited by a young child. As each behavior was eliminated, another maladaptive behavior occurred until the entire hierarchy of maladaptations had been exhausted. The problem is that there are many more potential abnormal than normal behaviors. When maladaptive behavior is maintained by reinforcing only events that behavior has produced, suppression of that behavior in a subject whose repertoire is limited almost certainly will yield other symptoms. This analysis implies that a set of maladaptive behaviors may be controlled by the same or similar reinforcement contingencies. Thus, suppression of a behavior high in the hierarchy would produce an increase lower in the organism’s hierarchy. Cahoon (1968) has suggested an alternative possibility, however. A response hierarchy might be composed of behaviors controlled by different reinforcement mechanisms but under the control of the same discriminative stimulus. For example, the same set of discriminative cues might initiate both aggressive behaviors and SIBS although these are maintained by different reinforcement contingencies. Under these conditions, suppression of one behavior would have little effect on other responses in the individual’s hierarchy, while an alteration of the discriminative stimulus complex would affect all responses contained within that hierarchy. This would account for collateral deceleration sometimes observed in one behavior when another topographically quite different behavior is punished. Lovaas and Simmons (1969) reported that the punishment of SIB was associated with decreased collateral “whining” behavior. Perhaps these behaviors were under control of the same discriminative stimuli so that suppression of one behavior altered the stimulus complex, thus reducing the frequency of nontarget collateral behaviors. There is still, of course, a third possibility. Behaviors can be uncorrelated, both in terms of their initiating conditions and their consequences. Under these

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conditions one would not expect treatment of one symptom to either accelerate or decelerate other behaviors.

IV. SUMMARY AND CONCLUSIONS

Self-injurious behavior (SIB) represents a serious problem among retarded individuals, particularly those residing in institutions. Clinical impressions of this situation are supported by several recent surveys which place the prevalence of SIB among the institutional retarded somewhere between 8 and 14%, depending upon definitions used and type of institution examined. Of the various forms of SIB, head banging and self-biting are the most common, although the variations seem to be endless. Many cases are extremely severe, resulting in permanent harm or even death. A negative relationship exists between frequency and severity of SIB, on the one hand, and functional level of the individual on the other. Males exhibit more severe forms of SIB than females, although actual prevalence may be greater among females. Even though it is common practice to regard SIB as pathological, mild forms of these behaviors are often observed among “normal” individuals, particularly infants. Theoretically, it is probably inappropriate to conceptualize SIB as a discontinuous variable, with a clean and clear distinction between those who are deviant and those who are not. Moreover, some self-injurious behaviors are highly rhythmical and stereotyped in form, while others are exhibited only infrequently and under highly stimulus-specific situations. It may well be that these are not functionally the same behaviors. A variety of theories have been proposed to explain or, in some cases, interpret SIB. For purposes of convenience we have classified these as follows: Homeostatic, Psychodynamic, Organic, Developmental, and Learning. These are not mutually exclusive positions. The major distinguishing characteristic among these theories has to do with the role of environmental variables. Probably all these theories possess some validity. However, learning has provided the major conceptual basis for intervention. While it is not possible to state with assurance that SIB has its origins in learned behavior, the evidence at hand clearly supports the conclusion that this behavior is often maintained by instrumental conditioning. Drug therapy and physical restraint have historically represented the most common methods for dealing with SIB. The few systematic studies pertaining to these methods are not particularly reassuring. Much the same can be said for “supportive” therapy. On the other hand, deliberate and systematic enrichment of the environment either by providing patterned visual and/or auditory stimulation seems to decelerate SIB. Various operant conditioning procedures, including differential reinforcement of other behaviors, extinction, time out, and punishment, probably are useful in

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suppressing SIB to some extent. Of these, the punishment procedures are generally the most effective. Three practical problems must be considered in the modification of SIB: (1) generalization, (2) durability, and (3) symptom substitution. Surprisingly little systematic research has been reported with respect to these issues. However, it is clear from the literature as well as from our own experience that the problem of generalization is an acute one. Behaviors that are shaped are often trainer- and situation-specific and subjects, even severely retarded ones, are capable of making fine discriminations between conditions when i t is “safe” to engage in these behaviors and those conditions when such behaviors will be punished. It is doubtful whether any behavior modification effort to reduce SIB will be successful unless deliberate fading of social and environmental stimuli is included as an integral part of the training program. Behavior modification is essentially generative in nature and cannot sustain behavior without constant control of the discriminative and reinforcing conditions. If we return a subject to the discriminative and reinforcing conditions that initiated and maintained the SIB previously, we should not be astonished to observe a recovery in response rate. The question of durability of suppression effects shares some of the same considerations just mentioned in regard to generalization. Research is sparse on this point but, as a general rule, aversive conditioning methods probably produce greater durability of suppression than other methods. This should be particularly true if the subject is also taught an alternative behavior. Obviously, the contingencies themselves (e.g., type of reinforcement schedule) will have considerable influence on durability of suppression. Again, it seems reasonable to assert that complete elimination of the behavior will come about to the extent that the behavioral repertoire is enlarged or reordered t o produce consequences which are adaptive for the subject. A third therapeutic consideration involves the development of collateral behaviors or symptom substitution. It is only recently that this problem has received any direct research attention, but clearly it is a problem of considerable magnitude. Unless a trainer makes careful observations, preferably taking multiple response measures, the situation may be made worse rather than better. Given the evidence at hand, we must conclude that even partial suppression of any behavior is inevitably accompanied by acceleration of some other behavior. Frequently, these collateral behaviors may be as harmful to the subject or as undesirable as the targeted behavior. REFERENCES Allen, K. E., & Harris, F. R. Elimination of a child’s excessive scratching by training the mother in reinforcement procedures. Behavwur Research and Therapy, 1966,4,79-84.

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Ayllon, T., & Awin, N. H. h i s h m e n t as a discriminative conditioned reinforcer with humans. Journal of the Experimental Analysis of Behavior, 1966,9,411419. Azrin, N. H., Gotlieb, L., Hugart, L., Wesolowski, M. D., & Rain, T. Eliminating selfinjurious behavior by educative procedures. Behaviour Research and Therapy, 1975.13, 101-11 1.

Bachman, J. A. Self-injurious behavior: A behavioral analysis. Journal of Abnormal Psychology, 1972,80,211-224. Bachman, J. A., & Wincze, J. P. The effects of contingent and noncontingent electric shock punishment on self-injurious and crying behavior. Paper presented at the ninth annual convention of the Association for the Advancement of Behavior Therapy, San Francisco, December, 1975. Bandura, A. Principles of behavior modification. New York: Holt, 1969. Banks, M., & Locke, B. J. Self-iqiurious stereotypies and mild punishment with retarded subjects. Working Paper No. 123, Parsons Research Center, Parsons, Kansas, 1966. Baumeister, A. A., & Forehand, R. Stereotyped acts. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 6 . New York: Academic Press, 1973. Pp. 55-92.

Bender, L. Secondary punishment and self-punitive avoidance behavior in the rat. Journal of Comparative and Physiological Psychology, 1969,69,261-266. Bender, L., & Harnell, H. An observation nursery: a study of 250 children in the psychiatric division of Bellevue Hospital. American Journal of Psychiatry, 1941,97,1158-1174. Berkson, C . Stereotyped movements of mental defectives: VI. No effect of amphetamine or a barbiturate: Perceptual and Motor Skills, 1965,21,698. Berkson, G. Development of abnormal stereotyped behaviors. Developmental Psychologv, 1968,1,118-132.

Brown, J. S., Martiin, R. C., & Morrow, M. W. Self-punitive behavior in the rat: facilitative effects of punishment on resistance to extinction. Journal of Comparative and Physie logical Psychology, 1964,57,127-133. Bryson, Y., Sakati, N., Nyhan, W., & Fish, C. Self-mutilative behavior in the Cornelia de Lange syndrome. American Journal of Mental Deficiency, 1971,76,319-324. Bucher, B., & Lovaas, 0.I. Use of aversive stimulation in behavior modification. In M. R. Jones (Ed.), Miam’ symposium on the prediction of behavior, 1967: Aversive stimulation. Coral Gables, FIa.: University of Miami Press, 1968. Pp. 77-145. Bychowski, C. Problems of infantile neurosis: A discussion. Psychoanalytic Study of the Child, 1954,9,66-68. Cahoon, D. D. Symptom substitution and behavior therapies: A reappraisal. PsychologictaI Bulletin, 1968,69,149-158. Corte, H. E., Wolf, M. M., & Locke, B. J. A comparison of procedures for eliminating self-injurious behavior of retarded adolescents. Journal of Applied Behavior Analynk, 1971,4,201-213.

Wvenport, R., Menzel, E., & Rogers, C. Effects of severe isolation on “normal” juvenile chimpanzees.Archives of General Psychiatry, 1966, 14,134-138. DeLissovoy, V. Headbanging in early childhood: A study of incidence. Journal of PediaMcs, 1961,58,803805. Dunham, P. J. Some effects of punishment upon unpunished responding. Journal of the Experimental Analysis of Behvior, 1972,17,443-450. Epstein, L. H., Doke, L. A., Sajwaj, T. E., Sorrell, S., & Rimmer, B. Generality and side effects of overcorrection. Journal of Applied Behavior Analysh, 1974.7,385-390.

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Fitzherbert, J. The origin of headbanging: A suggested explanation with an illustrative case history. Journal of Mental Science, 1950, %, 793-695. Forehand, R.. & Baumeister, A. A. Body rocking and activity level as a function of prior movement restraint. American Journal of Mental Deficiency, 1970, 74,608610. Forehand, R., & Baumeister, A. A. Deceleration of aberrant behavior among retarded individuals. In M. Herson, R. M. Eisler, & P. M. Miller (Eds.), Progress in behavior modification. New York: Academic Press. 1976. Pp. 223-278. Foxx, R. M., & Auin, N. H. The elimination of self-stimulatory behavior by overcorrection. Journal of Applied Behavioral Analysis, 1973,6,1-14. Cenovese, E., Napoli, P. A., & Bolego-Zonta, N. Self-agressiveness. Life Sciences, 1969, 8, 513515. Gesell, A., & Amatruda, C . S. Developmental diagnosis. New York: Harper, 1947. Green, A. Self-mutilation in schizophrenic children. Archives of General Psychiatry, 1967, 17,234-244. Green, A. Self-destructive behavior in physically abused schizophrenic children, Archives o f GeneralPsychiatry, 1968, 19, 171-179. Greenacre, P. Problems of infantile neurosis: A discussion. Psychoanalytic Study of rhe Child, 1954,9, 37-38. Greene, R. J., & Hoats, D. L Aversive tickling: A simple conditioning technique. Behavior Therapy, 1971,2, 389-393. Hamilton, J., Stephens, L., & Allen, P. Controlling agressive and destructive behavior in severely retarded institutionalized residents. American Journal of Mental Deficiency, 1967,71,852-856. Holz, W . C., & AzM, N. H. Discriminative properties of punishment. Journal of the Experimental Analysis of Behavior, 1961,4,225-232. Jones, F. H., Simmons, J. Q., & Frankel, F. An extinction procedure for eliminating self-destructive behavior in a 9-yearald autistic girl. Journal of Autism and Childhood Schizophrenio, 1974,4,241-250. Kohlenberg, R. J., Levin, M., & Belcher, S. Skin conductance changes and the punishment of self-destructive behavior: A case study. Mental Retardation, 1973, 10, 11-13. Kravitz, H., & Boehm, S. Rhythmic habit patterns in infancy: Their sequence, age of onset, and frequency. Child Development, 1971.42, 399-413. Kravitz, H., Rosenthal, V., Teplitz, Z., Murphy, J., & Lesser, R. A study of headbanging in infants and children. Diseases of the Nervous System, 1960,21,203-208. Lester, D. Self-mutilating behavior. Psychological Bulletin, 1972,78, 119-128. Levinson, C. The development of head banging in a young rhesus monkey. American Journal of Mental Deficiency, 1970,75,323328. Levy, D. M., & Patrick, H. T. Relation of infantile convulsions, head banging and breathholding to fainting and headaches in the parents. Archives o f Neurology and Psychiatry, 1928,19,865-887. Lourie, R. S. The role of rhythmic patterns in childhood. American Journal of Psychiany, 1949,105,653660. Lovaas, 0 . I., Frietag, G., Gold, V. J., & Kassorla, I. C. Experimental studies in childhood schizophrenia: Analysis of selfdestructive behavior. Journal of Experimental Child PSyChOlOgy, 1965,2,67-84. Lovaas, 0. I., & Simmons, J. Q. Manipulation of self-destruction in three retarded children. Journal of Applied Behavior Analysis, 1969,2,143-157. Maisto, C. R., & Baumeister, A. A. A multivariate analysis of self-injurious behavior among institutionalized retarded persons. Unpublished manuscript, University of Alabama, 1975. Menninger, K. Man against himself: New York: Harcourt, 1938.

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Merbaum, M. The modification of self-destructive behavior by a mother-therapist using aversive stimulation. Behavior Therapy, 1973,4,442-447. Miron, N . B., & Rooney, J. R. The accidental acquisition of stimulus control during the extinction of self-injurious behavior in severely retarded children. Unpublished manuscript, Sonoma State Hospital (California), 1973. Napolitan, J. T., & Peterson, R. Treatment effects and response generalization with stereotyped behavior. Paper presented at the Midwest Association of Behavior Analysis, First Annual Convention, Chicago, May, 1975. Peters, J. M. Caffeine induced hemorragic automutiliation. Archives Internotionales de Pharmacodynomie et de Therapy, 1967, 169, 139-146. (Cited in Lester, 1972). Peterson, R. F., & Peterson, L. R. The use of positive reinforcement in the control of self-destructive behavior in a retarded body. Journal of Experimental Child Psychology, 1968,6,351-360. Repp, A. C., & Deitz, S. M. Reducing aggressive and self-injurious behavior of institutionalized retarded children through reinforcement of other behaviors. Journal o f Applied Behavior Analysis, 1974,7,313-315. Ribble, M. A. The rights of infants: Early psychological needs and their satisfaction. New York: Columbia University Press, 1943. Risley, T. The effects and side effects of punishing the autistic behaviors of a deviant child. Journal of Applied Behavioral Analysis, 1968,1,21-34. Rollings, J. P. The establishment of extroceptive stimulus control of stereotypic responding exhibited by two profoundly retarded males. Unpublished doctoral dissertation, University of Alabama, 1975. Rollings, J. P., Baumeister, A. A., & Baumeister, A. A. The use of overcorrection procedures to eliminate the stereotyped behaviors of retarded individuals: An analysis of collateral behaviors and generalization of suppression effects. Behavior Modification, in press. Rollings, J. P., & Melvin, K. B. Effects of a punitive noise on self-punitive running established with shock. Psychonomic Science, 1970,21,313-314. Ross, R. T. Behavioral correlates of levels of intelligence. American Journal of Mental Deficiency, 1972,76,515-519. Sajwaj, T., & Hedges, D. “Side-effects” of a punishment procedure in an oppositional, retarded child, Paper presented at the meeting of the Western Psychological Association, San Francisco, April 1971. Sandler, J. Reinforcement combinations and masochistic behavior: A preliminary report. Psychological Reports, 1962, 11, 110. Sandler, J., & Davidson, R. S. Psychopathology: An analysis of response consequences. In H. D. Kimmel (Ed.), Experimental psychopathology: recent research and theory. New York: Academic Press, 1971. Pp. 71-93. Saposnek, D. T.. & Watson, L. S., Jr. The elimination of the self-destructive behavior of a Psychotic child: a case study. Behavior Therapy, 1974,5,79-89. Schroeder, S. R. The analysis of self-injurious behavior: Pathogenesis and treatment. Unpublished study, University of North Carolina and Murdock Center, 1974. Shentoub, S., & Soulairac, A. L’enfant auto matilateur. Cited in A. A. Green, Archives of General Psychiatry, 1967,17,234-244. Shodell, M., & Reiter, H. Self-mutilative behavior in verbal and non-verbal schizophrenic children. Archives of General Psychiatry, 1968.19,453-455. Skinner, B. F. Science and human behavior. New York: Macmillan, 1953. Smeets, P. M. Some characteristics of mental defectives displaying self-mutilative behaviors. Training School Bulletin, 1971,68,131-135. Smolev, S. R. Use of operant techniques for the modification of self-injurious behavior. American Journal o f Mental Deficiency, 1971,76,295-305.

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SoUte, D., & O’Brien, D. Self injurious behavior in a state center for the retarded: Incidence. Research and the Retarded. 1974, Spring, 1-8. Spitz, R. A. Hospitalism: A follow-up report. The Psychoanalytical Study of the Child, 1946,2,113-117. Spock, B. The common sense book of baby and child care. New York: Duell, Sloan & Pearce, 1945. Tanner, B. A,, & Zeiler, M. Punishment of self-injurious behavior using aromatic ammonia as the aversive stimulus. Journal of Applied Behavior Analysis, 1975,8,53-57. Tate, B. G. Case Study: Control of chronic self-injurious behavior by conditioning proce dures. Behavior Therapy, 1972, 3,72-83. Tate, B. G., & Baroff, G. S. Aversive control of self-injurious behavior in a psychotic boy. Behaviour Research and Therapy, 1966,4,281-287. Thomas, R. L., & Howard, G, A. A treatment program for a seXdestructive child. Mental Retadation, 1971,9, 16-18. Webster, D. R., & Azrin, N. H. Required relaxation: A method of inhibiting agitativedisruptive behavior of retardates. Behavior Research and Therapy, 1973, 11,67-78. White, G. D.,Nielsen, G., & Johnson, S. M. Timeout duration and the suppression of deviant behavior in children. Journal of Applied Behavior Analysis, 1972,5,111-120. White, J. C., Jr., & Taylor, D.J. Noxious conditioning as a treatment for rumination. Mental Retadation, 1967,5,30-33.

Willoughby, R. H. The effects of t i m e a t from positive reinforcement on the operant behavior of preschool children. Journal of Experimental Child Psychology, 1969, 7, 299-313. Wolf, M., Rkley, T., & Mees, H. Application of operant conditioning procedures to the behavior problems of an autistic child. Behavwur Research and Therapy, 1964, 1, 305-312. Wright, L. Aversive conditioning of self-induced seizures. Behavior Therapy, 1973, 4, 7 12-7 13. Yeakel, M. H., Salisbury, L. L., Greer, S. L., & Marcus, L. F. An appliance for autoinduced adverse control of self-injurious behavior. Journal of Experimental Child Psychology, 1970,10,159-169. Zuk, G . H. Psychodynamic implications of self-injury in defective children and adults. Journal of Clinical Psychology, 1960,16,58-60.

Toward a Relative Psychology of Mental Retardation. with Special Emphasis on Evolution

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HERMAN H SPIT2

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EDWARD R JOHNSTONE TRAINING AND RESEARCH CENTER. BORDENTOWN. NEW JERSEY

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I Evolutionary Psychology A. Two Kinds of Evolution B Uniquely Human Traits C The Human Power of Reasoning D TheHumanBrain II Mental Retardation Viewed as a Thinking Disability III A Framework for a Relative Psychology of Mental Retardation A The Stereotyped Response B PerformanceCongruence C Rote Memory D Digit Span: Rote Learning or Strategic Behavior? E Strategic Behavior in Learning. and Complex Learning F . Abstractions and Logical Problem Solving lv summingup References

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1 EVOLUTIONARY PSYCHOLOGY

In order to move toward greater theoretical understanding and the establishment of general laws. scientists must periodically bring order to empirical findings Unless they find some cohesive element in the array of data. the data are useless. Data do not automatically order themselves into a pattern of

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Herman H. S p i n

elegance and beauty; the human mind alone has the inherent capacity for the productive and economical mganization of vast amounts of apparently unrelated material. In the natural sciences, nontrivial phenomena have been unified in ways that give us predictive understanding of many important natural events. The most productive theoretical ordering of data in the biological sciences is the theory of evolution (Darwin, 1872, 1873, 1874). It is surprising, therefore, that psychologists have made so little use of this theory. There have been some encouraging attempts to place psychology within an evolutionary framework (e.g., Ekman, 1973; Freedman, 1974; Ghiselin, 1973; Goodson, 1973; Munn, 1971; Razran, 1971; Roe & Simpson, 1958; Stenhouse, 1974), but most psychological theories ignore evolutionary principles. Contrast this general ignorance of evolution with the closely related work of ethologists, who consistently point out the ways in which animal and human behavior evolved adaptively (e.g., Lorenz, 1965; Tinbergen, 1973). Viewed from the perspective of natural selection, human brain processes must have evolved because they possessed certain biological advantages. It is generally agreed that our species survived not because of any outstanding physical capacity, but primarily because of its great brain, capable of complex learning, foresight, strategic and adaptable behavior and, finally, capable of the development of tools and language. Human beings are, above all, thinking animals. Our brains have become so large that much of our early maturation takes place after birth, since further enlargeme?? of the infant’s head would require even further widening of the female pehic birth canal. Consequently, human infants remain helpless for a relatively longer period after birth than do the infants of other animals. A. Two Kinds of Evolution

Unlike nonhuman animals, mankind has undergone two kinds of evolution (Huxley, 1964). The first, biological evolution, is common to all animals. In biological evolution, innate propensities are transmitted genetically. In the human animal-because of certain fortunate genetic circumstances-there were born, periodically, exceptionally brilliant and creative individuals. The important point for mankind is that the discoveries made by these gifted people could be given to others and-by spoken and written record, and imitation-passed from generation to generation. This passing of increased and diverse information down the generations constitutes the second kind of evolution: cultural evolution. Although cultural evolution is seen occasionally in other animals, it is largely confined to humans, where it has been dramatically influential. Recently discovered nonliterate tribes give us some idea of the extent of cultural evolution; and the rapid adjustment of one such a tribe after sustained contact with an advanced culture attests to

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the dual evolution of mankind, for without the basic brain processes provided by biological evolution they would be incapable of adjusting in such a remarkable manner (Mead, 1954). Since cultural evolution, superimposed upon biological evolution, results in relatively little biological change, it is likely that our brains are structurally not very different from the brains of our ancestors when cultural evolution began (Munn, 1971, pp. 221-223). The results of this state of affairs are devastating. We have advanced technologically on the basis of our capacity to transmit information derived from a relatively few exceptionally bright and talented individuals. Technological and medical advances have allowed humans to overpopulate and dominate the planet. But the thin veneer of civilization readily breaks down. There are untold instances in which “civilized” people behave in barbaric fashion, as during the holocaust of Nazi Germany. Similar kinds of unspeakable behavior can be observed in nonliterate people, particularly under stress (Turnbull, 1972). The term “civilization” does not imply advanced morality; enlightened as well as barbaric behavior occur in both literate and nonliterate societies. We can learn much about living together in peace, for example, from the Tasaday tribe recently discovered in the jungles of the Phillipines (Nance, 1975). For our purpose, however, it is necessary to determine the intellectual traits which differentiate human (both literate and nonliterate) from nonhuman animals. It is assumed that these traits had developed during biological evolution and, among other things, led to cultural evolution. It is further assumed that all humans possess these traits to varying degrees, and that intellectual genius is a reflection of the highest endowment and development of these particular capacities, while mental retardation is a condition in which these capacities are deficient and/or defective (but not usually absent). We must begin to think of mental retardation in terms of evolution. On the one hand, we who are engaged in the scientific study of mental retardation can contribute to the study of evolution. I have attempted to do this by pointing out that even extremely retarded individuals possess sophisticated language skills and yet are deficient in certain high-level cognitive skills. Consequently, it is possible that language developed quite early in man’s evolution, at least prior to the capacity for high-level conceptualization (Spitz, 1973~).On the other hand, we can draw on evolutionary theory by trying to understand precisely which traits developed late in biological evolution, and examining the retarded on these particular traits. B. Uniquely Human Traits

Are there any uniquely human intellectual traits? Darwin (1874) came to the conclusion that there were none, that the differences between human and

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nonhuman animals are quantitative, not qualitative. He agreed with many other writers of his time that the most important distinction between humans and the lower animals is in the development of a moral sense. This moral sense, derived from social instincts present in many animals, was said to be more highly developed in humans because of their concern for the approval of their fellows and because of the self-punitive effects of their vivid memory of past wrongdoing.’ The generation of highly complex language is another obvious distinction which Darwin ascribed to the advanced level of intelligence of our species. In The Descent of Man, he stated that an imperfect language, aided by gestures, might have been used very early in man’s history, and that: “Without the use of some language, however imperfect, it appears doubtful whether man’s intellect could have risen to the standard implied by his dominant position at an early period” (p. 205). He believed that “man has an instinctive tendency to speak, as we see in the babble of young children” (p. 97), and that language evolved “slowly and unconsciously . . by many short steps” (p. 97). A number of traits were discussed by Darwin (1874) in the context of hwnan-nonhuman differences. He found the following traits to exist in varying degrees in many nonhuman animals: imitation, excitement, wonder, curiosity and imagination, attention, memory and, finally, that trait which Darwin called the summit, the most fundamental part of man’s nature: reasoning. According to Darwin, all the traits exhibited by human animals can be found in some nonhuman animals, the difference being the degree to which many of the traits, particularly the power of reasoning, were developed in man. Of course these conclusions strengthened Darwin’s thesis that man developed from some less highly organized form. He stated, for example (Darwin, 1874, p. 697), that u.. .the mental powers of the higher animals.. are the same in kind with those of man, though so different in degree.. . .” On the same page, he stated that the “half-art and half-instinct” of language produced a great stride in the development of intellect, and noted that the exercise and interplay of many lower level mental faculties produced, eventually, such higher intellectual faculties as ratiocination, abstraction, and self-consciousness. There have been, before and after Darwin, innumerable attempts to ferret out the fundamental differences between human and nonhuman animals. Hobhouse (1915, p. 319) for example, ascribes the differences to the fact that humans, with the help of language, have “. . . a distinct method of organizing or correlating. experiences,” of relating facts to their unique stock of general ideas. Suffice it to say that despite the application to this problem of our finest minds, the definitive answer still eludes us. It does appear, however, that our power of reasoning, assisted by the use of symbols and language, is so far beyond

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’For one view of the biological evolution of ethical and altruistic behavior, see Wilson (1975).

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that of nonhuman animals that it becomes, in a sense, qualitatively different. Dobzhansky’s (1962, 1972) discussion of these issues is especially illuminating. C. The Human Power of Reasoning

Reasoning, of course, is a very general term. We think of it now as, among other things, the power of abstraction, but it had a different form in its rudimentary development. Nonhuman animals can reason, but some unique type of reasoning allowed our remote ancestors not only to survive but to proliferate and eventually to dominate. Bartholomew and Birdsell (1953) point out that the essential element of survival is food getting. Populations are limited by the food supply available 12 months of the year. If, for a nonhibemating species, there is ample food available most of the time, but a limited food supply at certain periods during the year, then the population of that species is limited by the food supply during those barren periods. The probability is very good that such a situation existed for our ancestors, yet we know that they increased not only their population, but also their territory. It is assumed, therefore, that they must have acquired the capacity for the storage of food; not the blind, instinctual storage of certain mammals, but a planned, useful strategy. This is just one example of the capacity to plan ahead, to exhibit foresight, and to understand relations, which typifies the essential reasoning power of our ancestors. They also exhibited foresight when they hunted and carried tools and instruments. That is, unlike other animals, they kept tools for future use. They recognized redundancies in the seasonal and tidal cycles and hunted and planned accordingly. Without planning and foresight they could not have survived, for they had neither the physical attributes nor many of the instinctual drives of other animals. Reasoning, primarily in the form of foresight and a primitive form of abstraction (perceiving universals), decisively separated them from other animals. It was a trait of such adaptive significance that it must certainly have been a favored trait in the course of human evolution. D. The Human Brain

We must examine more closely the particular aspects of the human brain which allowed for this development. There is the important fact of man’s large brain weight to body weight ratio (Jerison, 1973), but the description I intend to make is not in terms of physical attributes but in terms of the manner of functioning. I would like to suggest that one way to describe the human brain is to call it a self-organizing, negentropic system. The self-organizing aspect acts primarily outside of conscious awareness, while the negentropic aspect occurs primarily in consciousness.

Herman H. Spitz

40 1. THE SELF-ORGANIZING BRAIN

Although stimuli impinge on the brain as a mosaic, they are perceived as organized structures. The self-organizing mind imposes structure. This is no more mysterious, of course, than the fact that certain embryonic cells will form legs, others arms, and so forth. I would like to propose that this self-organizingtrait has evolved in human beings to an advanced state, a small example of which can be seen in a frequently noted phenomenon: A problem solution will emerge when the thinker is occupied with other thoughts. This has been documented time and again as a process that frequently occurs in scientific discovery (e.g., Koestler, 1964). Many scientists, while performing other activities and thinking of other things, will find that a solution to a problem or an idea for a crucial experiment will suddenly come to mind. Of course the scientist must be steeped in the subject matter, but somehow there is a sudden interlocking of previously unrelated ideas. Creative artists more frequently depend on this sort of insight. A related phenomenon occurs in memory and is so common an occurrence as to be instantly recognizable: diligently and unsuccessfully searching for a name only to have it pop into consciousness when intentional search has ceased. This remarkable faculty of the brain indicates that the focus of the brain is never wholly centered on a single activity. It is engaged at many levels in many activities, only one of which is conscious, as Freud knew so well. But Freud stressed the emotional and interpersonal aspects of this capacity; there is a huge intellectual component which deserves greater study. 2. THE NEGENTROPIC BRAIN

Humans can be described as negentropic (exhibiting negative entropy) because of their persistent striving to bring order out of disorder and to abstract information out of noise. In my opinion this is the one capacity which, in its fullest development, is the most uniquely expressive of higher intelligence. It is the essence of reasoning and is described nicely by Einstein who wrote that ordering element . . . connects series which in thinking occurs when an themselves are unconnected. Such an element becomes an instrument, a concept. . Thinking is characterized by the more or less dominating role which the ‘concept’ plays in it” (Einstein, 1970, p. 7). It is this ability which, in its primitive form, was manifest in the planning and foresight of our ancestors, and in their finding of redundancies and universals. In its highest form, the theory of evolution itself is an excellent example of how the discovery of a common element can unify an apparently diverse mass of observable facts. This capacity to build order out of chaos is reflected also in the pleasure we gain in finding solutions. The essential drive to find a lawful solution to an enigma is reflected in daily solutions to daily problems as well as in the general theory of relativity, although at vastly different levels.

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If the essential capacity for abstracting is innate, rudiments of this trait are likely to be found early in life. Hull (1920) gave the example of a 16-month-old child who was fond of playing with a lighted 8-candle-power lamp. One day, Hull held a lighted candle in front of the child, who touched the flame. When the candle was lighted again, she shrank from it. The next day she was offered the lighted lamp she had played with previously and she shrank from that also. But when the current of the lamp was turned off, she took it in her hands as readily as ever. Similar results were obtained several times the following day. This is one example of what Hull called a “generalizing abstraction.” The adaptive significance of this type of behavior is obvious. By the same reasoning, the tendency of young children to overgeneralize can serve as a protective mechanism. With maturation, classes of categories become more selective (Gibson & Gibson, 1955), and overgeneralization decreases. Empirical studies support anecdotal evidence. Children as young as 2 years remember pairs of items better when the items belong to the same conceptual category than when they do not (Goldberg, Perlmutter, & Myers, 1974). Rosch (1973) found that the Dani of Indonesian New Guinea, described as a Stone Age people who possess only two color terms, roughly “dark” and “light,” learned natural prototypes of color categories faster than sets which violated natural prototypes. Her results lent support to the contention of Berlin and Kay (1969) that there are innate color focal points. Rosch also found that, as with color, salient prototypical forms (circle, square, triangle) influenced form categories, although the Dani live in an uncarpentered world. Rosch concluded that when category names are learned, natural prototypes become the focus of organization for the categories. There are philosophical and logical arguments for the proposition that all human beings are born with abstractive ability. Hayek (1970) argues that the richness of the sensory world is the product, not the source, of the range of abstraction which the mind possesses, and that the mind must be capable of abstracting operations prior to conscious awareness of particulars. Adult humans have a larger number of abstract classes than do children and consequently they confer additional, richer attributes upon elements, rather than the other way around. That is, experience with many elements does not by itself enrich abstractions, but rather maturation provides the advanced abstractive capacity t o enrich sensations. Weimer (1973) argues that we must return to Plato’s conception that the “essences” (realities) of things lay hidden behind their appearance, and that the underlying reality is preexistent. Indeed, science has revealed that the reality of objects is quite different from their appearance. In linguistics the evidence is also very good that there is an underlying structure that allows for the productivity of surface language (Chomsky, 1965), since a speakerhearer’s knowledge of language is infinitely greater than prior learning history would allow. Certainly perception is susceptible to this type of analysis, and very likely cognition also.

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From this viewpoint, concept formation is seen, as with language, to stem from a preexistent conceptual framework. We are born to perceive objects not as particular and isolated, but as instances of universals. It is just as logical to believe that the idea of universals precedes the idea of the particular as it is to believe the reverse, and such a viewpoint allows one to deal more adequately with the problem of productivity outstripping experience. Without a prior Conceptual framework, we cannot impose order. According to Plato, learning is actually remembering, since reality is passed down by the soul. In place of Plato’s soul, Weimer substitutes evolution: the evolved central nervous system provides us with certain competences which determine the form of behavioral capacity.

II. MENTAL RETARDATION VIEWED AS A THINKING DISABILITY

With this brief background, let us turn now to the syndrome of mental retardation. With rare exceptions, mental retardation is viewed not as a disorder of thinking but as a disorder of learning. However, recent research indicates that the mentally retarded are slow learners largely to the extent that thinking contributes to learning, and the evidence is increasing that in many learning tasks, particularly laboratory learning tasks, strategic behavior is critical (Brown, 1974). The structure of most retarded persons’ learning and memory systems appears to be intact, for the mildly and moderately mentally retarded forget no more than the nonretarded, relative to what they initially acquire. But the retarded acquire less, largely (although not entirely) because they use inadequate organizational and other strategic devices (Spitz, 1966). When the human brain is viewed as a self-organizing, negentropic system, what can be said about mental retardation? There is, to my knowledge, no direct way to measure how productively self-organizingan individual CNS may be. But there are some very indirect measures of the spontaneous reorganization of which the brain is capable. One such indirect measure is the spontaneous fluctuations observed when viewing ambiguous and reversible figures. This is a perceptual phenomenon and it is hazardous to generalize from perceptual to intellectual processes. Nevertheless, it has been noted that the mentally retarded report fewer reversals than nonretarded people of equal chronological age (CA) (Spitz, 1963). Additional inferential evidence can be found in electroencephalographic (EEC) studies. In reviewing this area, Hughes (1968, p. 125) reported that poor organization and development of the alpha background activity was a frequent finding with mentally retarded people. Visualevoked potentials also appear to be different in retarded and nonretarded individuals (e.g., Calbraith, Clidden, & Busk, 1970).

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The evidence for reduced negentropic processing in the mentally retarded is more direct. Whereas in simple rote memory experiments and in many other simple performance tasks the retarded perform at a level commensurate with their MA, when performing tasks requiring capacities which presumably developed late in mankind’s biological evolution the retarded do not perform up to their MA level (Spitz, 1973~).The retarded have relatively more difficulty than equal MA normals in recognizing and utilizing information-reducingredundancies (Borys & Spitz, 1974; Spitz, Goettler, & Webreck, 1972) and have relatively greater difficulty developing a lawful principle and displaying foresight in problem-solving and logic games, both nonverbal (Spitz & Nadler, 1974; Spitz & Winters, in press) and verbal (Denny, 1974). Although the negentropic capacity to categorize and abstract remains operative even in mentally retarded people with rather low IQs (see, for example, Hermelin & O’Connor, 1958), performance deteriorates when verbal material is substituted for perceptual material (Spitz, 1966, p. 41); and the categories used by the retarded are maturationally behind those of equal MA normal children (Denney, 1975; Winters & Brzoska, 1976). Additionally, the retarded, after learning to organize one set of categories, are less likely to generalize to different sets of categories (e.g., Bilsky, Evans, & Gilbert, 1972; Gejuoy & Alvarez, 1969). The relatively poor performance of retardates in studies of concept utilization and categorical clustering may be viewed as examples of a general deficiency in the strategic use of certain limited-capacity traits. In Piagetian terms, they never reach the level of formal operations (Kolstoe, 1971), and on logical problemsolving tasks most mildly retarded people do not even reach the concrete operational level obtained by 8-year-old normal chil,&en (Spitz & Nadler, 1974).

111. A FRAMEWORK FOR A RELATIVE PSYCHOLOGY OF MENTAL RETARDATION

We must now attempt to arrange this material into some sort of meaningful pattern; negentropy demands that we do so. The attempt is made in Fig. 1 where the relative performance of groups of people at various intellectual and maturational levels is displayed. There is no pretense that Fig. 1 is definitive. Rather, it is a theoretical organization of the material to provide a frame of reference within which experimenters may operate. Empirical evidence has been extrapolated and compressed into a form which, it is hoped, has useful conciseness as well as predictive power. Along the abscissa, going from left to right, we move from what I consider primitive “old world” tasks to tasks reflecting the latest evolutionary development of Homo supiens. Six different, arbitrarily defmed intellectual and maturational groups are compared on the various tasks. Straight lines of different

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is

ician Educable Adolescent and Adults Average 8-9 yr Old Y ln

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0 2

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Averagc (2 yr O l d

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l3 n W

$ d

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Averagc Adult Superioi Adult

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FIG. 1. Outline of proposed group relationship on various types of tasks.

intercepts and different slopes trace the relative performance of different groups from primitive tasks to the more complex conceptual tasks. Suffice to say there are no accurate numbers to describe group differences or functions, for we cannot pretend to be at that stage of knowledge. Rather, the group differences are relative: the larger the spatial separation of the graph, the larger the difference in performance. It should be emphasized that this is an idealized graph, dependent on certain idealized conditions. Variations in tasks, among many other variables, could easily alter the relationships. The schema is given merely as a framework in which to order data, and should not be taken more seriously than that. Note that on the right-hand ordinate, which specifies performance on tasks requiring abstractions and logical problem solving, simple problems can be solved by educable retardates, but the summit of these traits is the attainment of scientifically productive theories. There is a continuum here, and a relationship between simple problem solving and theory construction which has intimate connections with the negentropic capacities previously discussed. A random series of binary numbers (e.g., 01 1010000101) or a random series of observations cannot be encompassed by any principle. In order to convey complete information about such a series, each number must be given. This requires as

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many bits of information as there are in the series. On the other hand, a lawful series (e.g., 001100110011) can be described by a principle which not only conveys the numbers in fewer bits of information but also contains perfect predictive power. By the same logic, the smaller the number of bits contained in a theory, the greater its comprehensiveness and understanding (Chaitin, 1975). The capacity of theoreticians to find redundancies and derive principles which unify apparently diverse material differs only in level from the manifestation of the same trait in normal adults. And we see that the attempt to understand mental retardation is carried out using the very processes which retardates possess in such small measure. Those familiar with this field will recognize that elements of Fig. 1 are not new. Many workers have suggested that a deficiency in reasoning and perceiving relations is primary in mental deficiency; Burt (1961, p. 528) placed reasoning at the head of his hierarchy of normal-retardate differences. Aspects of Jensen’s (1970) two-level theory are here, and even the crossover in performance curves-in which the retarded perform better than the nonretarded on certain types of problems, as on the left of Fig. 1, while the reverse is true on more difficult problems-has been diagrammed by Zeaman and House (1967, p. 199). In the field of normal developmental psychology many proposals, including Piaget’s, could be used along the abscissa. Brown’s (1975) recent memory model is also relevant. What is novel in Fig. 1 is the attempt to show the relative performance from a number of different maturational and intellectual levels over a number of different task requirements. The schema depicted in Fig. 1 was based on extrapolations from a limited number of empirical studies, and it has generated additional studies. I will not attempt to be comprehensive; relevent reviews can be found elsewhere (e.g., Brown, 1974, 1975; Zeaman & House, 1967). Rather, based primarily on studies from our laboratory with educable retarded adolescents, a few examples will be given to illustrate some of the relationships displayed. A The Stereotyped Response

In studies of learning, stereotyped responses are here defined as those which display sequentially repetitive choices which appear to be unrelated to the stimuli. Examples would be perseveration (choosing one side repetitively) or single-response alternation (alternating sides at each successive choice). In discrimination learning experiments, for example, stereotyped responding appears to reflect an inability (or unwillingness) to abstract and respond to stimulus dimensions. Gerjuoy and Winters (1968) provide evidence that retarded people regress to response alternation when a binary-choice discrimination learning task is too difficult for them. Presumably, stereotyped responses are a primitive type of response, with perseveration being more primitive than alternation. These

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types of responses are relatively higher in the response hierarchy of the maturationally young and retarded (Gerjuoy & Winters, 1968). However, the relationships concerning stereotyped responding given in Fig. 1 do not refer simply to whether or not subjects respond in a stereotyped manner. What is required to confirm the predictions is evidence that when a stereotyped response sequence is the wmct response retarded subjects will learn faster than nonretarded subjects of at least 8 or 9 years of age. When I first drafted Fig. 1 there were no such studies available. Consequently, we devised one (Spitz, Carroll, &Johnson, 1975a). Our study was carried out within the theoretical framework of Levine’s (1969) hypothesis theory. According to this theory there are two classes of hypotheses which subjects make in a discrimination learning experiment: (1) prediction hypotheses-reflected in reasonable responses based on some stimulus attribute, and (2) response-set hypotheses-reflected in arbitrary stimulus preferences or position sequence responses chosen by the subject for want of anything better to do. We reasoned that if the stimuli were complex, college subjects would make prediction hypotheses based on attributes of the stimuli, while retarded subjects would regress quickly to a response-set hypothesis. Put another way, the college subjects should have a large set of prediction hypotheses to draw from, with the response-set hypothesis of single alternation very low in their hierarchy; the retarded subjects should have a small set of prediction hypotheses, with single alternation higher in their hierarchy. All we had to do, therefore, was to make the stimuli very complex and make single alternation the correct solution. The stimuli we used were 20 pairs of stylized Japanese symbols. Twenty college subjects and 20 educable retarded subjects of equal chronological age (mean IQ of 58) were told that one symbol of each pair was the correct one to choose, that they should point to it, and that they would be told if they were correct or not. The first response, no matter to which side, was positively reinforced, as was each subsequent response made to the opposite side of the previously chosen stimulus. Results were very clear. At the first opportunity to alternate (the second response) 25% of the subjects in each group alternated. Thereafter the retarded group alternated an average of 75% on each trial, which was reliably above chance, while the college group alternated at chance level. The retarded group performed reliably better than the college group, thereby confirming the prediction in Fig. 1 that educable retardates will have relatively greater success on a task requiring a stereotyped response than will superior adults. Although our study was carried out within the framework of Levine’s (1969) hypothesis theory, the results support the attention theory of Zeaman and House (1967), who also made the specific prediction (pp. 205-206) that since subjects of low developmental level tend to respond to position in a two-choice

RELATIVE PSYCHOLOGY OF MENTAL RETARDATION

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task, they should perform better than normals on position discrimination leaming. However, they never carried out the experiment. B. Performance Congruence

It should be noted that in Fig. 1 there is a point, just before Rote Memory, where most of the groups converge. At the time this schema was devised I had no inkling as to what task would fit on the abscissa here, but a number of possibilities have since arisen. Basic syntax of language is one possibility, but of course this is not usually measured by experimental tasks. Brown (1975) has suggested that there are no developmental differences in recognition memory, although results are contaminated by ceiling effects. She also reports that certain tasks requiring discrimination of relative recency require no deliberate mnemonic and are developmentally insensitive over the age range of 7 years to college age. In any case, the convergent points for the various groups represent an interesting challenge. C. RoteMemory

It is difficult to measure pure rote memory which is uncontaminated by cognitive processes. Humans naturally use various mnemonic devices to. reduce the memory load, devices which range from looking at and touching the to-be-remembered item, at 3 years of age (Wellman, Ritter, & Flavell, 1975), to simple covert naming of pictures, beginning at about 5 to 6 years of age (Conrad, 1971), to increasingly sophisticated strategies (Brown, 1975; Neimark, Slotnick, & Ulrich, 1971). Perhaps a purer measure of rote memory, therefore, would be incidental learning, where input mnemonics presumably cannot influence the results. However, it is important in such experiments that the subjects at least attend to the incidental material (by naming it, for example), or else group differences can be ascribed to attention rather than retention processes. Two studies meet this criterion. As part of a study (Spitz, Winters, Johnson, & Carroll, 1975b) we had subjects name each of 49 chromatic pictures, presented sequentially, in order t o insure that the pictures could be identified. As far as the subjects were concerned, their task was merely to identify each picture. However, recall was requested after the last picture. The educable retarded adolescents recalled an average of 11.64 pictures, while the equal MA (about 9.5 years) nonretarded children recalled an average of 1 1.75 pictures, a difference which is not statistically significant. I could find only one other study using retarded subjects where the objects to be incidefitally remembered were named, but this time it was the experimenter

48

Herman H. Spitz

who named the objects. Hetherington and Banta (1962) compared braindamaged, familial, and educable retarded children with nonretarded children of equal MA (about 6 years, with mean IQ 40 points higher than the retarded) and found that, although the brain-damaged group recalled less incidental material than the other two groups, there were no differences between any of the groups on a 48-hour recall test of the incidental material. None of the groups differed on intentional learning either, but at this age it is not likely that mnemonic strategies were utilized by the normal children. Another method of eliminating mnemonic devices is to present material in a single, brief exposure, as in the measurement of sensory (iconic) storage. In one such experiment, Pennington and Luszcz (1975) found that the performance of educable retarded subjects paralleled that of equal CA subjects (college students) and was at only a slightly lower level. In other words, there was only a small, though reliable, difference between college students and educable retardates. In general, no differences in iconic memory are found when retarded and equal MA nonretarded subjects are compared (Spitz, 1973b).

D. Digit Span: Rote Learning or Strategic Behavior?

Perhaps the simplest memory experiment is the recall of digits. Reviews of digit span performance of retarded and nonretarded people have been given elsewhere (Spitz, 1973a, 1973b), but a few representative studies will be noted here. When comparing educable retarded adolescents with 9- to 10-year-old third graders of approximately equal MA, the third graders recall 6 digits reliably better, but not 4 or 8 digits, where floor and ceiling effects appear to be operating (Spitz, Goettler, & Webreck, 1972). The average maximum digit recall (when digits are presented at the typical 1-second rate) for educable retarded subjects of about 7.25 MA is about 1 digit less than for equal MA and equal CA nonretarded subjects (Frankel & Tymchuk, 1974). Even at MAS as low as 3-5 years, retarded people recall fewer digits than nonretarded people (Thompson & Magaret, 1947). When using as a criterion digit length successfully recalled by at least 90% of the subjects, a review of a large number of studies indicates that the digit span of educable retarded adolescents is 3-4 digits, while for high school and college students it is 5-7 digits (Spitz, 1973b). No firm conclusion can be drawn from these data since even in this simple task subjective strategies can play a role: The digits will be grouped and/or rehearsed by some subjects but not by others (Spitz, 1973a). However, the fact that there are performance differences at matched MAS as low as 3-5 years, with no evidence that retardates use different grouping strategies than matched MAS of 9-10 years (Spitz et a l , 1972), suggests that there is a small but consistent retardate deficit on this simple memory task.

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E. Strategic Behavior in Learning, and Complex Learning

Differences in favor of nonretarded people of equal MA begin to emerge with greater consistency when the material and experimental procedure are such that strategic behavior can play a role. In fact, the more that the nature of the task permits strategic behavior in learning, or requires complex learning, the greater the likelihood that brighter and older (up to college age) nonretarded groups will outperform retarded groups by a wide margin. Zeaman and House (1967) have suggested that, in verbal learning experiments, when retarded and nonretarded groups of equal MA differ by 40 or more IQ points performance differences will be found, but when differences are only 20 to 30 IQ points, they are minimal or absent. Ceiling and floor effects will also obscure group difference. However, there are exceptions to this general rule. For example, in a task in which material was presented sequentially in a horizontal array, retarded adolescents recalled as many pictures as equal MA (9.5 years) nonretarded children who had an average IQ approximately 50 points higher. It was only when the retarded subjects, under changed conditions, used a less efficient order of recall strategy that the nonretarded subjects’ recall was superior (Spitz et aL, 1975b). This follows the general finding that when retarded individuals spontaneously use the same strategies as the nonretarded, or are supplied with or induced to use such strategies (without the same help being given to normals), recall is usually comparable (Brown, 1974; Jensen, 1965; Spitz, 1966). The problem is that children with MAS of at least 8-9 years frequently use more efficient strategies than do retarded people. In complex learning situations, differences are even more likely to arise. For example, retarded children and adolescents have difficulty when arithmetic is presented in verbal form (Cruickshank, 1948), and it has been reported that they read at least one grade below their MA level (Dunn, 1954). Differences are frequently found on tasks which require verbalization of abstractions and, in my opinion, are most clearly found on tasks requiring logical problem solving.

F. Abstractions and Logical Problem Solving There have been studies which show that institutionalized retarded people are at least 2 years behind their MA in certain types of concept tasks, both when verbal (Griffith, Spitz, & Lipman, 1959) and pictorial (Denney, 1975) material are used. The retarded are capable of using concepts, of course, but they tend more often to use functional and thematic relatedness as the basis of their concepts, while equal MA nonretarded children of at least 7- to 8-year MA more frequently use common elements and superordinates. In the work by Griffith et aL (1959), the retarded were about 2 years behind their MA in the ability to generalize an abstraction based on the definition of

Herman H. Spitz

50

only one of the words. That is, 9-year-old nonretarded subjects were likely to attain the abstraction “all dark” to the question: How are night, cave, and closet alike? if they defined at least one of the words as “dark” in a separate vocabulary test. For most of the retarded adolescents of M A 9, and for nonretarded 7-year-olds, it was necessary to define at least two of the words in terms of the abstraction before they attained the concept. A subsequent study by McIvor (1972) in a classroom setting indicated that training on hypothesis testing improved performance on this abstraction task far more than did pairedassociate training of the definitions. Evidently, retarded people are deficient in the capacity to spontaneously generate this type of hypothesis, although they can be taught to do so. Blount (1971) demonstrated that retarded children can form abstractions when concepts are familiar to them, although even in such instances they continue to be deficient in verbalizing the relationships. But the area of logical problem solving, so infrequently studied, has turned up some of the most dramatic differences between retarded and equal M A nonretarded people. These differences occur not only in verbal problem-solving tasks (eg., Kolstoe & Hirsch, 1974; Litton, 1973; Tucker, 1970), but also in gameplaying situations (Spitz & Nadler, 1974; Spitz & Winters, in press). In many of these tasks retarded people seem to have difficulty separating redundant from

CORRECT RESPONSE

FIG. 2. An example of a two-pattern problem-solving task presented in a complex board. Lower section shows correct response and was not on test board. From Spitz & Nadler, 1974, Copyright 1974 by the American Psychological Association. Reprinted by pdS8iOn.

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nonredundant information (e.g., Goodstein, Cawley, Gordon, & Helfgott, 1971; Spitz & Nadler, 1974). I was able to find only one study in which retarded and equal M A nonretarded subjects (of 9-year MA) did not differ on a reasoning task (Johnson & Blake, 1960). In the Spitz and Nadler (1974) study we used a logical problem-solving task (shown in Fig. 2) in which the subject needed to open only the single correct lever to obtain all the information needed to answer the question: Which pattern is hidden? Opening either of the other two levers was redundant, since they provided no information. Even after extehsive training, the retarded subjects were unable to perform above chance on this task, and they performed at a level equivalent to that of nonretarded children 2 years below their MA. When the experimenter opened the correct lever for the subjects, or if they opened the correct lever by chance, their responses were invariably correct; but they could not generate the correct response by systematically choosing the correct lever to open. When the task was simplified by the use of the problem board shown in Fig. 3 (Nadler, 1974), they performed slightly above chance, but no better than nonretarded children of much lower MA. In general, retarded subjects could not establish a reliable principle to guide their behavior. In a related experiment, we used an adaptation of the popular tic-tac-toe game to further explore this pronounced effect (Spitz & Winters, in press). The subject,

FIG. 3. An example of a two-pattern task on a simple board. (Nadler, 1974.)

Herman H. Spitz

52

playing the X’s, was required to make one response which would assure a win (see Fig. 4). Ample pretraining and the presence of “lie items” embedded in the task assured us that the subjects knew how to play the game. This task apparently requires much the same capacity for foresight as did the task used by Spitz and Nadler. The subjects must make an “if-then” analysis in which they must visualize how their response will change the circumstances. It is, in fact, the same type of analysis that must be made in checkers or chess, but at a much simpler level. Our results indicated that retarded subjects performed approximately 1% years below expectations based on the performance of nonretarded children of equal MA. It appears that differences between retarded and nonretarded groups in complex learning, abstraction, and problem solving increase with increasing MA. One might predict that on these tasks, when comparisons are made at MA 8 to 10 years, differences will be greater than when they are made at M A 6 years, because at 6 years the normal children have not yet reached the point where they are capable of more complex strategies. Put another way, on these traits retarded people asymptote at a relatively low MA. The type of intellectual games children play, such as tic-tac-toe, has evolutionary significance. The play of young mammals of many species provides practice for similar types of adult behavior. For example, the kitten’s stalking 1

4

10 1 1 1

3

5 ILI

4

11

12

FIG. 4. Examples of tietac-toe task. Asterisk indicates correct reponse. (L)=lie item. (Spitz &Winters,in press.)

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and pouncing on a rolling ball is a prelude to the hunting of mice. In the course of evolution it is likely that those young animals whose play trained them on important adult behaviors were more likely to survive, so that preparatory play became a favored trait. That young humans play intellectual as well as physical games suggests that in mankind’s development, intellectual play became a rehearsal for an important type of adult behavior. The difficulty encountered by retarded adolescents in these games is, therefore, extremely informative.

IV. SUMMING UP

It is the contention of this chapter that a marked deficiency on tasks requiring foresight and logical analysis, as well as, though to a somewhat lesser extent, on tasks requiring verbal abstractions and conceptualizations, represents a deficiency in traits which developed late in mankind’s evolutionary development. From the evolutionary viewpoint, laboratory studies such as these are small, isolated segments of general traits which developed over the course of biological evolution, traits which our ancestors used in an entirely different context in order to survive. It has been said that the brain is the most complex system in the known universe. By looking at our experiments as isolated bits of behavior we can not appreciably advance our understanding of this complex system. But the theory of evolution has increased immeasurably our understanding of behavior, and by placing our studies within an evolutionary context we can benefit from its knowledge and contribute to its progress. REFERENCES Bartholomew, G. A., Jr., & Birdsell, J. B. Ecology and the protohominids. American Anthropologist, 1953,55,481-498. Berlin, B., & Kay, P. Basic color terms: Their universality and evolution, Berkeley: University of California Press, 1969. Bilsky, L., Evans, R. A, & Gilbert, L. Generalization of associative clustering tendencies in mentally retarded adolescents: Effects of novel stimuli. American Journal of Mental Deficiency, 1972,71,71-84. Blount, W. R. Concept-usage performance: Abstraction ability, number of referents, and item familiarity. American Journal of Mental Deficiency, 1971,76,125-129. Borys, S . V., & Spitz, H. H. Effects of temporal grouping and redundancy level on the paired-associate learning of retarded adolescents and non-retarded children. American Journal of Mental Deficiency, 1974,79,443-448. Brown, A. L. The role of strategic behavior in retardate memory. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 7. New York: Academic Press, 1974. Brown. A. L. The development of memory: Knowing, knowing about knowing, and knowing how to know. In H. W . Reese (Ed.), Advances in child development and behuvior. Vol. 10. New York: Academic Press, 1975.

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Burt, C. f i e backward child. (5th ed.) London: University of London Press, 1961. Chaitin, a. J. Randomness and mathematical proof. Scientific American, 1975,232,47-52. Chomsky, k. Aspects of a theory of syntax. Cambridge, Mass.: MIT Press, 1965. Conrad, R. The chronology of the development of covert speech in children. Developmental Psychology, 1971,5,39&405. Cruickshank, W. M. Arithmetic ability of mentally retarded children, 11. Journal ofEducationa~Research, i948,42,279-288. Darwin, C. The origin o f species (6th ed.) New York: Mentor, 1958. (Originally published, 1872.) Darwin, C. The expression of the emotions in man and animals. London: Murray, 1873. Darwin, C. The descent of man, and selection in relation to sex. (2nd ed.) New York: Burt. 1874. Denney, D. R. Recognition, formulation, and integration in the development of interrogative strategies among normal and retarded children. Child Development, 1974, 45, 1068-1 076. Denney, D. R. Developmental changes in concept utilization among normal and retarded children. Developmental Psychology, 1975,11, 359-368. Dobzhansky, T. Mankind evolving. New Haven, Conn.: Yale University Press, 1962. Dobzhansky, T. Genetics and the diversity of behavior. American Psychologist, 1972, 27, 523-530. DUM, L. M. A comparison of the reading processes of mentally retarded and normal boys of the same mental age. Monographs of the Society for Research in Child Development, 1954,19(1, Whole No. 58). 1-99. Einstein, A. [Autobiographical notes.] In P. A. Schilpp (Ed. and trans.), Albert Einstein: Philosopher-scientist.(3rd ed.) La Salle, Ill.: Open Court, 1970. Ekman, P. (Ed.) Darwin and facial expression. New York: Academic Press, 1973. Frankel, F., & Tymchuk, A. J. Digit recall of mentally retarded and non-retarded children under three presentation rates. American Journal of Mental Deficiency. 1974, 79, 311-319. Freedman, D. G. Human infancy: A n evolutionaty perspective. Hillsdale, N.J.: Erlbaum, 1974. Galbraith, G. C., Glidden, J. B.. & Busk, J. Visual evoked responses in mentally retarded and nonretarded subjects. American Journal o f Mental Deficiency, 1970,75,341-348. GerjUoY, 1. R., & Alvarez, J. M. Transfer of learning in associative clustering of retardates and normals. American Journal of Mental Deficiency, 1969,73, 733-138. Gerjuoy, I. R., & Winters, J. J., Jr. Development of lateral and choice-sequence preferences. In N. R. Ellis (Ed.), Internotional review of research in mental retardation. Vol. 3. New York: Academic Press, 1968. Chiselin, M. T.Darwin and evolutionary psychology. Science, 1973,179,964-968. Gibson, J. J., & Gibson, E. J. Perceptual learning: Differentiation or enrichment? Psychological Review, 1955,62, 3 2 4 1 . Goldberg, S., Perlmutter, M., & Myers, N. Recall of related and unrelated lists by 2-yearolda Journal of Experimental Child Psychology, 1974,18, 1-8. Godson, F. E. The evolutionary foundations o f psychology. New York: Holt, 1973. Goodstein, H. A., Cawley, J. F., Gordon, S., & Helfgott, J. Verbal problem solving among educable mentally retarded children. American Journal ofMental Deficiency, 1971,76, 238-241. Criffith, B. C., Spitz, H. H., & Lipman, R. S. Verbal mediation and concept formation in retarded and normal subjects. Journal of Experimental Psychology, 1959, 3, 247-251. Hayek, F. A. The primacy of the abstract. In A. Koestler & J. R. Symthies (Eds.), Beyond reductionism New York: Macmillan, 1970.

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Hermelin, B., & O'Connor, N. The rote and concept learning of imbeciles. Journal of Mental Deficiency Research, 1958,2,21-27. Hetherington, E. M., & Banta, T. J. Incidental and intentional learning in normal and mentally retarded children. JournaI of Comparative and Physiological Psychology, 1962,

55,402-404. Hobhouse, L. T. Mind in evolution. New York: Amo, 1973. (Originally published, 1915.) Hughes, J. R. Electroencephalography and learning. In H. R. Myklebust (Ed.), Progress in learning disabilities. VoL 1. New York: Grune & Stratton, 1968. Hull, C. L. Quantitative aspects of the evolution of concepts. Psychological Monographs, 1920,28(1,Whole No. 123). Huxley, J. Psychometabolism: General and Lorenzian. Perspectives in Biology and Medicine,

1964,7,399-432. Jensen, A. R. Rote learning in retarded adults and normal children. American Journal of Mental Deficiency, 1965,69,82&834. Jensen, A. R. A theory of primary and secondary familial mental retardation. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 4. New York: Academic Press, 1970. Jerieon, H. J. Evolution of brain and intelIigence. New York: Academic Press, 1973. Johnson, G. 0,, & Blake, K. A,, Learning performance of retarded and normal children. Syracuse: Syracuse University Press, 1960. Koestler, A. The act of creation. New York: Macmillan, 1964. Kolstoe, 0. P. Defining mental retardation. In E. H. Williams,J. F. Magary, & F. A. Moore (Eds.), Ninth annual distinguished lecture series in special education and rehabilitation. Los Angeles: University of Southern California Press, 1971. Kolstoe, 0. P., & Hirsch, D. F. Convergent thinking of retarded and nonretarded boys. Exceptional Children, 1974,40,292-293. Levine, M. Neo-noncontinuity theory. In G. Bower & J. T. Spence ma),The psychology of learning and motivation Vol. 3. New York: Academic Press, 1969. Litton. F. W. A comparison of problem-solving ability in the educable mentally retarded. Unpublished doctoral dissertation, University of Northern Colorado, 1973. Lorenz, K. Evolution and modification of behavior. Chicago: University of Chicago Press,

1965. McIvor, W. B. Evaluation of a strategyaiented training program on the verbal abstraction performance of EMRs. American Journal of Mental Deficiency, 1972,76,652-657. Mead, M. Cultural discontinuities and personality transformation. Journal of Sociol Issues, 1954,Suppl. No. 8,316. Munn, N. L. The evolution o f the human mind. Boston: Houghton, 1971. Nadler, B. T. Effects of varying stimulus characteristics on the logical problem solving behavior of normal six year olds and educable retarded adolescents. (Doctoral dissertation, Rutgen University) Ann Arbor, Mich.: University Miaofilms, 1974. No. 75-17, 360.Dissertation Abstracts International, 1975,36,320A-321A. Nance, J. Thegentle Tamday. New York Harcourt, 1975. Neimark, E.. Slotnick, N. S., & Ulrich, T. Development of memorization strategies. Develop mental Psychology, 1971,5,427-432. Pennington, F. M., & Luszcz, M. A. Some functional properties of iconic storage in retarded and nonretarded subjects. Memory & Cognition, 1975,3,295-301. man,G.Mind in evolution Boston: Houghton, 1971. Roe, A., & Simpson, G. G. (Eda) Behavior and evoIuriOn New Haven, Corn.: Yale University Press, 1958. Rosch, E. H. Natural categoriea CognitivePsychology, 1973,4,32&350.

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Spitz, H. H. Field theory in mental deficiency. In N. R. Ellis (Ed.), Handbook of mental deficiency: Psychological theory and research. New York: McGraw-Hill, 1963. Spitz, H. H. The role of input organization in the learning and memory of mental retardates. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 2. New York: Academic Press, 1966. Spitz, H. H. The channel capacity of educable mental retardates. In D. K. Routh (Ed.), The experimental psychology of mental retardation, Chicago: Aldine, 1973. (a) Spitz, H. H. Consolidating facts into the schematized learning and memory system of educable retardates. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 6. New York: Academic Press, 1973. (b) Spitz, H. H. Evolutionary processes and mental deficiency. Journal of Special Education, 1973,7,343-356. ( c ) Spitz, H. H., Carroll, J. G., & Johnson. S. J. Hypothesis testing from a limited set: An example of mentally retarded subjects outperforming college subjects. American Journal of Mental Deficiency, 1975,79,736-741. (a) Spitz, H. H., Goettler, D. R., & Webreck, C. A. Effects of two types of redundancy on visual digit span performance of retardates and varying aged normals. Developmental Psychology, 1972,6,92-103. Spitz, H . H., & Nadler, B. T. Logical problem solving by educable retarded adolescents and normal children. Developmental Psychology, 1974, 10,404412. Spitz, H. H., & Winters, E. A. Tic-tac-toe performance as a function of maturational level of retarded adolescents and nonretarded children. Intelligence, in press. Spitz, H. H., Winters, J . J., Jr., Johnson, S. J., & Carroll, J. C. The effects of spatial, temporal, and control variables on the free-recall serial position curve of retardates and equal-MA normals. Memory & Cognition, 1975,3,107-112. (b) Stenhouse, D. The evolution of intelligence. New York: Barnes & Noble, 1974. Thompson. C. W., & Magaret, A. Differential test responses of normals and mental defectives. Journal o f Abnormal and Social Psychology, 1947,42,285-293. Tinbergen, N. The animal in its world. Cambridge, Mass,: Harvard University Press, 1973. Tucker, R. C. A study of the logical abilities of children as a function of mental and chronological age. (Doctoral dissertation, St. Louis University) AM Arbor, Mich.: University Microfiis, 1970. No, 7 1-21, 429. (Dissertation Abstracts International, 1971,32,1369-1370.) Turnbull, C. The mountain people. New York: Simon & Schuster, 1972. Weimer, W. B. Psycholinguistics and Plato’s paradoxes of the Meno. American Psychologist, 1973,28,15-33. Wellman, H. M., Ritter, K., & Flavell, J. H. Deliberate memory behavior in the delayed reaction of very young children. Developmental Psychology, 1975, 11,780-787. Wilson, E. 0. Sociobiology: The new synthesis. Cambridge, Mass.: Belknap Press, 1975. Winters, J. J., Jr., & Brzoska, M. A. The development of the formation of categories by normal and retarded persons. Developmental Psychology, 1976,12, 125-131. Zeaman, D., & House, B. J. The relation of IQ and learning. In R. M. Gagnk (Ed.), Learning and individual differences. Columbus, Ohio: Merrill, 1967.

The Role of the Social Agent in Language Acquisition: Implications for Language Intervention1

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GERALD J MAHONEY2 AND PAMELA B.SEELY DEPARTMENT OF PSYCHOLOGY. UNIVERSITY OF ROCHESTER. ROCHESTER. NEW YORK

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1 Introduction

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A . GeneralProblem B Is Language Learned? C Theoretical Perspectives I1 Interactional Strategies Associated with Language Development A Preverbal Communication Strategies B. The Linguistic Environment .................................... C Functional Aspects of Maternal Speech D Child Language Learning Strategies E General Summary and Discussion 111 Implications of the Role of the Social Agent for Language Intervention A Communicative Match B Communication Deficiencies and Delayed Language Development ....... C Implications for Language Intervention D Toward a Communication Model References

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1 INTRODUCTION

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A General Problem

Language intervention programs for mentally retarded children may be classified according to whether they: (1) attempt to promote the development of This paper was supported in part by postdoctoral fellowship 1 F22 HD02144-01 from The National Institute of Child Health and Human Development to the senior author ‘Present address: Special Education Research Program. University of California at Los Angeles. Los Angeles. California 90002

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Gerald J. Mahoney and Pamela B. Seek)

cognitive processes which seem essential for the acquisition of language; (2) remediate social processes which are involved in language development; or (3) both develop cognitive processes and remediate social processes (Lee, 1974). Two issues are, consequently, of central concern to those who design language intervention programs: First, what cognitive prerequisites and cognitive processes are involved in language acquisition; and second, what social processes are involved in language acquisition? Only the social processes associated with language development are analyzed in this chapter. Cognitive, linguistic, and social factors are most likely interdependent in the process of acquisition and to focus on one of these factors to the exclusion of the others distorts the actual pattern of language development. However, cognitive and linguistic factors have been treated most adequately in a recent volume on language intervention, while social factors were almost entirely ignored (Schiefelbusch & Lloyd, 1974). This was a serious omission for two reasons. First, since mental retardation is characterized by an impairment in adaptive behavior as well as by deficits in cognitive functioning (Grossman, 1973), those who are mentally retarded probably encounter difficulty in interpersonal interaction which is crucial for language development. Second, language is initially, and perhaps fundamentally, a mode of social transaction (DeLaguna, 1927; Mahoney, 1975). Language. therefore, never develops in a social vacuum. We are entirely in accord with the position that cognitive and linguistic factors are critical for language development, but we contend that delayed language development among mentally retarded persons may be attributed partly to deviance in the social process, and that the efficiency of language intervention programs may be enhanced by focusing primarily upon the social process. For the most part, the following review of literature focuses upon the development of nonretarded children. Unfortunately there has been only an extremely limited amount of research concerning the social processes of young mentally retarded children. We feel, however, that literature on normal development is particularly relevant to mental retardation for two reasons. First, one of the major issues of language intervention concerns the delineation of the nature of the social process and the extent of its influence on language development. The logical first step to investigating this problem is to analyze normal language development. Second, a review of this sort provides an organized framework for generating hypotheses and research regarding the social processes associated with mental retardation. A major research question in the field of mental retardation is: To what extent does the social interaction which is initiated or elicited by mentally retarded persons hinder their development? Furthermore, the approach of investigating normal development is consistent with many current language intervention programs in which instructional programs are based on contemporary theory and research regarding normal development (Bricker & Bricker, 1974; Miller 8c Yoder, 1974).

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B. Is Language Learned?

The crucial issue in an analysis of the social processes associated with language development concerns whether language is innate or learned. During the 1960s there were two general positions regarding this issue. Learning theorists such as Skinner (1957) posited that language development was essentially isomorphic to the learning of nonverbal behavior in subhuman organisms. Consequently, language development could be explained almost entirely in terms of a functional analysis of the environmental events associated with acquisition without postulating any specific capacity to learn language other than the ability to form associations. The innateness position was proposed primarily by transformational grammarians (Chomsky, 1957; McNeill, 1966; Menyuk, 1969) who maintained that language is composed of a highly complex structure with both deep and surface levels of organization and a set of rules for relating the two. They argued that the structure of language must be an innately determined process for two general reasons. First, children from varied environments master the structural component of language rapidly and in an almost fured sequence (Lenneberg, 1967). Second, associationist learning theory did not appear capable of explaining the development of a generative syntactic system (Chomsky, 1957, 1959; Palermo, 1970). It is our view that the arguments used to defend the position that language was innately determined have been illogical. First, to claim that associationist principles cannot account for the acquisition of a generative grammar could only indicate that language was innate if the formation of associations were the basis for all learning. While principles of association have been useful for explaining many aspects of learning, it is doubtful that these principles are the basis of all learning (Jenkins, 1974; Weimer & Palermo, 1974). Second, although the rapidity and sequence of language development suggests that it may be associated with biological factors, such evidence does not indicate that biological factors cause language development. Many aspects of behavior develop rapidly and regularly and yet most theorists maintain that learning plays a critical role in these developments (e.g., Piaget, 1951, 1952). Much of the empirical evidence which has been used to support the position that language is learned has been significant for the development of intervention programs, but of little value in terms of the general theoretical issue. Learning theorists have responded to the challenge of the innateness position by demonstrating both that generative language may be trained through conditioning (Baer & Guess, 1971, 1973; Clark & Sherman, 1975; Garcia, Guess, & Byrnes, 1973; Schumacker & Sherman, 1970) and that subhumans may learn a language which is characterized by generative syntax (Gardner & Gardner, 1969; Premack, 1971). While there is controversy regarding the validity of the generative grammars established in these studies (Brown, 1973; Fodor, Bever, & Garrett, 1974;

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McNeill, 1970), it is clear that limited verbal responses may be established by conditioning procedures. However, because these studies do not indicate how children develop language under natural conditions, it is impossible to determine the origins of grammatical structure in the natural environment on the basis of such evidence. We maintain that the only valid way to resolve the issue of whether language is an innate or learned process is to determine by empirical means whether the linguistic and communicative behavior of the social agent is functionally related to the linguistic and communicative behavior of the developing child. While investigations of this sort must be guided by general theories of language, it is unnecessary to have a priori conceptions of the nature of learning. The fundamental issue, therefore, should be that of how, or to what extent, the social agent influences language development, rather than that of how language development fits current conceptions of learning. C. Theoretical Perspectives

The role whch the social agent is perceived to play in language development depends partially upon what language is considered to be. Those who advocated that the most basic element of language is syntax investigated the role of the social agent only in terms of its effects upon syntactic development (Brown, Cazden, & Bellugi, 1969, Cazden, 1965). In general, little evidence was found that social agents influence the acquisition of syntax. While this syntactic position was widely accepted during the 1960s, recently there has been greater support for the position that language is structured primarily by semantic intention (Schlesinger, 197 1). For example, Bloom (1970) demonstrated that the syntax of primitive child utterances could not be characterized accurately without considering the semantic intention which those utterances conveyed. Brown (1973) concluded after analyzing the language protocols of 23 children during the early phases of language development that semantic categories provided the most heuristic method for characterizing grammatical development. The semantic approach is a radical departure from syntactic models of language acquisition with regard to the perceived role of nonlinguistic factors. A semantic-based grammar implies that cognitive development, or the development of meaning systems, is a prerequisite to linguistic development. Furthermore, t o the extent that social agents are crucial to cognitive development, semanticbased theories of language development provide a rationale for expecting that social agents also play a significant role in language development. Although the semantic approach enriched conceptions of the role of nonlinguistic factors in language development, the fundamental orientation of this approach is similar to the syntactic approach. That is, the semantic approach is designed to characterize children’s linguistic competence during language acquisition (Bowerman,

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1973; Brown, 1973; Schlesinger, 1971). Any competence model of language may potentially distort the role of psychological processes in language acquisition because competence models are not fundamentally concerned with performance or functional variables. Competence models are characteristically designed on the assumption that the communication function, i.e., the performance dimension of language, is secondary to the linguistic structure of language. Communication is viewed as developing from language as if it were a direct linear function of linguistic competence, and language is defined by linguistic structure rather than by the use of linguistic structure in communication. The apparent relevance of cognitive development to language acquisition has led several theorists away from this competence view of language acquisition t o considerations of how cognitive processing in the midst of verbal interaction might account for language acquisition. For example, MacNamara (1972) argued that the basis for language acquisition is in nonlinguistic cognitive activity. MacNamara’s thesis “is that infants learn language by first determining, independent of language, the meaning which a speaker intends to convey to them, and then by working out the relation between the speaker and the language” (p. 1). One implication of this position is that social agents must influence language acquisition by mediating children’s gap between language and meaning through the use of nonlinguistic cues. The concept of language acquisition strategies has evolved within the framework of the semantic approach and become a critical consideration in the description of language development. Most frequently, the term strategy refers to covert processes such as perception, interpretation, or assimilation (Bever, 1970; Bowerman, 1974; Ervin-Tripp, 1973). Nelson (1973) enriched this concept by suggesting that strategies include children’s overt verbal behavior such as imitation and asking questions, as well as the communicative behavior which adults use while interacting with the language learner. The term strategy is, therefore, currently used to classify any covert or overt behavior which either children or language models employ to enable children to decipher the linguistic code and to become productive language users. Since the focus of research has broadened to include semantics, language development is viewed by many as a system which is intricately bound to other developmental phenomena, especially cognitive and social development. Researchers are beginning to study how language is used in communication based on the rationale that “the uses of language are . . crucial to an understanding of how language is acquired, how it is initially used . . .” (Bruner, 1975, p. 1). Influential in this recent evolution in language acquisition theory is the speech acts model of language (Searle, 1969). Searle argues that the intention to communicate is central to language, and that any theory of language must account for the essential connection between language and communication. The speech acts model characterizes language as a communicative act in which formal

.

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linguistic structure is partly determined by the functions it serves. The functional meaning of a speech act consists of two components: (1) the propositional force and (2) the illocutionary force. The propositional force is the conceptual content and includes the acts of referring and predicating. The illocutionary force indicates how the utterance is to be taken or what the speaker’s attitude toward the utterance is, and includes acts such as stating, questioning, commanding, and promising. The propositional and illocutionary acts are not separate aspects of the speech act, but rather are inherent in the very nature of the speech act itself. The same propositional act may have a variety of illocutionary forces. Thus, the statement “Sam is writing a letter” could have the force of a question with appropriate intonation while retaining essentially the same referent and predicate. In the following review of the social processes the general position of the speech acts model of language is adopted. The advantage of a speech acts description of language is that it allows language to be viewed simultaneously in terms of the psychological processes of cognitive development and social interaction within the broad context of the development of communication. It also provides a theoretical framework in which social processes may play as critical a role in the development of linguistic competence as do cognitive processes. II. INTERACTIONAL STRATEGIES ASSOCIATED WITH LANGUAGE DEVELOPMENT

According to the speech acts model (Searle, 1969), the communicative function is the central defining feature of language. From this perspective, language acquisition is embedded in the communicative interaction between children and adults. The purpose of this section is to review the evidence that social interaction constrains the nature and rate of language growth. Research into the effect of social processes on language development has been hampered by the difficulty of establishing a causal relationship between patterns of social interaction and language growth. First, language development is difficult to measure. Language performance at any one time is as much a function of the social and physical constraints of the setting (Brown et al., 1969) as it is of the linguistic competence of the speaker, yet we want to measure the two independently. Second, the effect of social interaction on the child’s linguistic growth may not be immediately apparent. The behavior of a model may contribute to a child’s information processing rather than to his overt performance so that the effects of social interaction at TI are not evident until T2.Third, as in any study of behavior in natural settings, it is impossible to control other important variables, such as cognitive status, neurological status, and social history. It is, therefore, dangerous to attribute differential rates of language growth to any one of these factors.

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Researchers trying to explain language acquisition in natural settings must depend on correlational data as evidence. For example, patterns of social interaction which are repeatedly associated with the active periods of language learning are assumed to have some adaptive significance for the development of language. While correlations do not imply causality, high correlations between specific patterns of social interaction and language development provide sound evidence for causal relationships between these two factors if alternative hypotheses can be rejected. The review of social processes is organized to provide information regarding the following hypotheses. First, from infancy both language models and children use interactive strategies which lead to advances in the general communication and specific language abilities of children. Second, the strategies of language models and children are reciprocally related. Aspects of parental behavior, such as the form and content of the information transmitted, are modified by aspects of child behavior, such as the manner in which the child previously responded. Similarly, the communicative behavior of the parent provides information which leads the child to modify his language learning strategies. Third, both the language learning strategies of children and the language teaching strategies of language models change developmentally. The efficiency of a strategy at any one time should, therefore, be dependent upon the current level of cognitive development and communicative competence of the child. Behavior which qualifies as an interactive strategy relevant to language development should satisfy one or all of the following criteria: (1) it should establish a reciprocal relationship between the language model and child; (2)it should provide information to the other person; and (3) it should lead to higher forms of communication. A. Preverbal Communication Strategies

If language evolves from a more primitive communication network, then the analysis of the social processes involved in language acquisition should include the development of children’s communication processes from the time of infancy to determine their relative contribution to the acquisition of language. This endeavor should include the study of both vocal and nonvocal behavior of children within the context of dyadic interaction. 1. VOCAL BEHAVIOR

wing During the first year of life, crying brings the caretaker into contact with the child and leads to other interactive behavior intended to alleviate the child’s distress (Bowlby, 1969). In this sense, crying helps establish reciprocal relationships between infants and their caretakers. While mothers universally recognize a.

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that infants cry to signal distress of some sort, their judgments of the specific cause of crying are often related to their knowledge of the state of the infant rather than to any physiological characteristics of the cry itself (Lynipp, 195 1). Evidence is contradictory whether mothers can determine the needs of their children solely on the basis of crying patterns. Wolff (1969) played taperecorded cries of infants while their mothers were in adjoining rooms. Pain cries resulted in mothers entering to check on their infants far more often than did rhythmical basic cries. Muller, Hollien, and Murry (1974) asked mothers to identify tape-recorded infant crying as either a pain, hunger, or startle reaction. Some samples of hunger cries were identified correctly more often than chance, but none of the pain or startle cries were identified correctly. In addition, whether mothers listened to cries of their own infants or to those of other infants, they identified pain and startle cries as hunger responses more often than chance. Muller et aZ, (1974) concluded that mothers tend to identify most crying as a hunger response on the basis of crying patterns alone. The relationship between crying and higher forms of communication apparently depends on the manner in which mothers respond to their children's crying. Bell and Ainsworth (1972) observed 26 mother-infant dyads in their homes periodically throughout the first year of life. Contrary to predictions of stimulus-response learning theory, reinforcement of crying behavior during the first 3 months (e.g., responding by holding the infant) did not increase the frequency of crying at subsequent stages. By 8 to 12 months of age, infants whose mothers had been most responsive during the first 3 months cried less often and used more advanced communicative signals than those infants whose mothers responded less to crying.

b. Vocalization Vocalization between infants and their mothers appears to be reciprocally related functioning to establish and maintain dyadic contact. Bateson (1971) studied films of vocal interaction between an infant and its mother from the 49th to 105th day of life. The sequences of alternate vocalization were nonrandom with mother and child facing each other at close range and maintaining eye contact. Lewis and Freedle (1972) studied more than 80 motherinfant pairs as they interacted in natural settings when the infants were 12 weeks old. Their analysis indicated that a communication network exists between young infants and their mothers within which vocalizations are produced in nonrandom, sequential patterns. The frequencies of infant and maternal vocalization were positively related. Mothers vocalized "most frequently while their infants were vocalizing and vice versa. In addition, infants vocalized more when mothers looked or smiled at them, while mothers vocalized more when their infants were distressed or smiling. Early vocal interaction patterns may lay the groundwork for later communi-

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cative interactions. Beckwith (1971) studied vocalization patterns between 24 mothers and their adopted children at 8%months and 10 months. Mother and infant vocalizations were reciprocally related with the patterns of vocal interaction changing as the infant grew older. At 8%months, the more mothers talked to their babies, the less the babies vocalized. At 10 months, the more mothers talked to their babies, the more the babies vocalized. While the response of infants to maternal vocalization differed at the two ages, the rate of maternal vocalization remained constant. Beckwith suggests that those infants who received the most verbal stimulation tended to focus on detecting the meaning of maternal vocalizations at 8 months and then began t o use vocalizations as an instrumental behavior at 10 months. Some of the primitive semantic notions which are communicated in early child speech such as “object of’ and “location of’ may be embedded in the vocal communication network between 12-week-old infants and their mothers. Lewis and Freedle (1972) found that some infants, especially females, vocalized more when mothers vocalized to them rather than to someone else. This behavior may indicate that for these infants some precursory form of the concept “object of” exists within the interactive situation and may eventually be abstracted from it. Similarly, the frequency of infant vocalization changed when infants were unrestrained (in a playpen or on the floor) as opposed to closely confined (as on the mother’s lap). This sensitivity of infant vocalization to situational differences possibly indicates that infants possess a precursory semantic notion like “location of.” 2. NONVOCAL BEHAVIOR

a. Smiling and Facial Expression During the first few weeks of life, smiling may be elicited by unspecific moderate or intense stimulation (Ambrose, 1960, 1961) with an increasing tendency for smiles to be elicited most often by human social stimulation (Wolff, 1963). Smiling to faces increases up to 12 or 16 weeks, and after that period, smiling to strangers declines (Wahler, 1967; Wolff, 1969). Smiling may be elicited by nonsocial as well as social stimuli. Watson (1970) reported that 8-week-old infants smiled vigorously at mobiles when they began to recognize that the movement of the mobile was contingent upon their own behavior. Therefore, while initially smiling is elicited by nonspecific social stimuli, as children develop smiling tends to be elicited by social stimuli of increasing specificity as well as by nonsocial stimuli. Several functions of smiling seem to be related to the development of infants’ communication. First, infant smiling helps to establish and maintain reciprocal relationships by attracting the caretaker to the infant and by increasing the duration of proximity between the infant and caretaker (Ainsworth, 1967; Bowlby, 1969). Second, smiling and facial features in general are a source of

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affective and cognitive information. Depending upon the context in which a smile is elicited, smiles are interpreted as signals that the infant is happy, feels well, or approves of something. Since infants may smile when they recognize a person, object, or event (Kagan, 1967; Piaget, 1952; Zelazo, 1972), infant smiles may also be a cue to caretakers that the child recognizes the stimuli which elicit the smiles. Third, infant smiling may lead t o higher forms of communication by encouraging the caretakers to repeat an activity or to reproduce a variant of an activity which originally elicited a smile. The repetition of an act segments the child’s input into semantically relevant units. Since caretakers often label or describe such repeated acts, the child’s task of relating a label or utterance to an ongoing perceptual event is facilitated (Bruner, 1975). Parents may communicate to infants during the preverbal stage through smiling and facial expressions. Lewis and Freedle (1972) observed that infants vocalize more frequently when their mothers smile at them. In addition, infants seem able to detect affective information from facial expressions from about 6 months of age. Darwin (1877) observed that at 5 months his son reacted to his nurse’s feigned tears with a melancholy expression, the comers of his mouth well depressed. Buhler and Hetzer (1928) observed that by 5 months infants were capable of discriminating between angry and happy expressions and acting appropriately. All of the infants from 5 to 7 months responded appropriately to an angry face. Kreutzer and Charlesworth (1973) replicated these early studies. Ten infants at each of four age levels (4, 6, 8, and 10 months) were confronted by an experimenter who acted out angry, happy, sad, and neutral facial expressions accompanied by appropriate vocalizations. While the 4-month-old infants responded indiscriminately to the various expressions, infants who were 6 months and older discriminated between facial expressions by responding with attention or negative affect. b. Gestures Gestures are commonly assumed to play an important role in preverbal communication and in the initial phases of language usage (Bloom, 1970; Bruner, 1975; Dore, 1975). Children’s use of gestures has been studied systematically by only a few and no one has reported a systematic study of the development of communicative function of gestures. Werner and Kaplan (1 963), however, observed that gestures may be used to express affective states, to depict or represent objects or events, or to denote objects of reference. Infants begin to use their relatively stable and well-structured sensorimotor patterns depictively during the second half year. According to Werner and Kaplan (1963), gestural depiction originates with children responding to the movements of persons by changes in body posture or limb movement. For example, when parents rock in a rocking chair, children may respond by rocking on their own as if they were resonating to the parents’ rocking movement.

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Gradually, the gestural responses of children become differentiated from the model in two ways. First, the pattern of the children’s motor responses becomes similar to the depicted content. Second, children gradually begin to respond to movements of objects as well as to the nonkinetic aspects of objects. For example, children may react to a swinging brush by waving their hands or attempt to represent the round form of a fruit by inflating their cheeks. Children may also depict events without imitating by forming gestures which typify their manner of handling things or dealing with their milieu. For example, children may use shoveling movements to depict a shovel and pail, or pushing movements to depict toy trucks. Denotative pointing accompanied by vocal sounds such as “da” or “ta” (deixis) emerges approximately when children utter their first words. Pointing is preceded by more primitive forms of denotative reference such as turning and reaching and is hypothesized to have evolved from the grasping of objects (Werner & Kaplan, 1963). There is little research concerning the communicative function of caretaker gestures. Buhler and Hetzer (1928) found that infants discriminated between threatening and affectionate arm gestures at 7-8 months or slightly later than they discriminated positive versus negative facial. expressions and voices. The generality of the categories of gestures they tested, however, preclude any conclusions concerning children’s ability to detect the meaning of gestures. c. Coordinated Action

During interaction the movements of the mother and child are reciprocally related at several levels of complexity. One form of coordinated action observed in neonates is synchronous movement to adult speech. Condon and Sanders (1974) analyzed a motion picture of the body movements of 16 neonates while they listened to both spoken and tape-recorded American English and taperecorded Chinese. They found that the babies initiated or changed the direction of their movements simultaneously with shifts in the articulatory segments of the speech they heard, whether the language was English or Chinese. Furthermore, the babies synchronized their movements to speech whether or not the speaker was present, indicating that the babies were “tuning in” to the adult rather than the adult “tuning in” to the babies. Synchronous movement appeared to be the result of the infants’ unique language perceptual processes since it did not occur to nonspeech sounds such as tapping and it could not be explained as a randon co-occurrence. If caretakers can detect the synchronous movement of infants, this behavior may serve as a cue that infants are attending to linguistic behavior. Eye contact is another behavior which tends to be coordinated in infantcaretaker interaction. In adult conversation, eye contact signals the beginning of a social encounter and may communicate affective states or personal attitudes (Coss, 1970). Jaffe, Stern, and Peery (1973) observed the gaze behavior of six

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4month-old infants as they interacted with their mothers and an adult experimenter in a naturalistic play setting. They found that the patterns of gaze behavior indicated by the frequency of adult visual fmations to the infant’s face and infant fmations to the adult’s face conformed to a Markov chain model which approximated the dyadic patterns of adult vocal interaction. In gaze behavior, infants adopt the same sequential constraints which occur in the verbal conversations of adults. Although eye contact may not assume the same functions for an infant-adult pair as it does for an adult-adult pair, it clearly plays a role in establishing reciprocal relationships and may provide information to the adult regarding the infant’s attention. Other nonvocal behavior between infants and their caretakers appear to be reciprocally related. Bullowa (1973) observed mother-infant dyads in natural settings and found that infants engage in complex sequences of action with their mothers which make daily routines relatively smooth running. The following is an example of a play sequence between a Cmonth-old infant and her mother:

..

. ..

“. the mother pat(s) the infant’s open mouth rhythmically and the infant vocalize(s), producing between them an undulating sound. The infant’s vocalization starts and stops with the mother’s patting. The infant is equally cooperative in feeding, bathing, etc. She is able to go along with her mother in complicatedinteractional sequences” [p. 231. Bullowa argues that early interactional patterns gradually increase in complexity and eventually lead to patterns of linguistic communication. Neonates have a very limited repertoire of responses to fit into dyadic patterns. They will, for example,, orient to and conform posturally to an adult. In some fashion, sensitive mothers “tune in” to the capacities and rhythms of the infant and gradually draw them into performing organized interactive sequences of increasing complexity such as the one described above. Gradually, language is fitted into these interactive sequences. Bruner (1975) conducted a longitudinal study of six infants ranging from 7 to 13 months in age as they interacted with their mothers. Patterns of mother-child interaction in play situations developed in relatively specific ways such that they appeared to be analogues of primitive categories of communication and child speech. Mothers initially establish standardized forms of joint action with children and develop interactional formats in which the children can calibrate their attention with their mothers and learn to anticipate and interpret their mothers’ signals. During these action formats, mothers frequently mark segments of actions by the use of completives or completion markings. For example, when a child drops a ball in a bottle, his mother may exalaim “Good boy!” indicating to the child that “dropping” was a unified action pattern. In these situations, children often repeat the act and the mothers respond with a completive again reinforcing the unity of the action sequence. Bruner found that initially almost all motherchild interactions were activities in which the mothers were the agents

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and the children the recipients. However, as the children grew older, the patterns of interaction changed, with the mothers directing the children’s attention to the act rather than to themselves. Eventually, the children became the actors and the mothers the recipients. In general, mothers and their children communicate and develop their communication system through shared or coordinated action patterns. 3. SUMMARY

The development of language, or at least the anlagen of language development, is rooted in the patterns of interaction which occur during the preverbal period. Many patterns of interaction which superficially appear to be random were found to be nonrandom and at times sequentially related. Infant vocalization, eye contact, micro-body movements, and gross body movements were found to be reciprocally coordinated with one or several different behaviors of the social agent. The developmental progression of many of these patterns of interaction suggest that children gradually become capable of anticipating and interpreting the activities of the social agent while the social agents tune in to the children’s level of communicative competence. The literature is either contradictory or speculative concerning the informational function of interaction sequences. Evidence that mothers can detect the specific cause of crying on the basis of crying patterns alone is inconclusive. No studies have been reported in which mothers were either observed to, or asked to, respond to the informational component of infant smiling, although infant smiling serves the general communication function of maintaining proximity. The informational content of gestures was most speculative, although this mode may be used more than other nonverbal modes to communicate information. B. The Linguistic Environment

In this section language addressed to children is analyzed at four different levels: physical characteristics, syntactic structure, word order, and semantic structure. 1. PHYSICAL CHARACTERISTICS

Since adult discourse is broken, disrupted, and frequently ungrammatical, several have argued that language learners must be equipped with innate hypotheses about the structural regularities underlying adult speech (Chomsky, 1965; McNeill, 1966). The results of a recent investigation indicate, however, that when mothers speak to children 8 to 28 months old, they seldom produce broken sentences (I‘hillips, 1970). Similarly, when mothers speak to children between 18 and 26 months old, they produce fewer than one disfluency per 100 words, while when they speak to adults, they produce as many as 4.5 disfluen-

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cies per 100 words (Broen, 1972). Speech addressed to children between 18 and 24 months old is more than 50% slower than speech directed to adults (Broen, 1972), with brief pauses or breaks less than one-quarter of a second occurring between words in sentences (Phillips, 1970). The placement of pauses in child-directed speech is one potential source of syntactic information. Pauses greater than one-quarter of a second do not mark sentence boundaries reliably in speech addressed to adults, but more than 90% of the pauses in speech directed to children between 18 and 42 months, and more than 70% of the pauses in speech directed to children between 60 and 96 months, occur at sentence boundaries (Broen, 1972; Dale, 1974). Dale (1974) found no evidence that child-directed speech is segmented at other syntactically relevant units such as phrase boundaries. It is possible, therefore, that pauses between sentences accentuate units of meaning which occur most frequently at sentence boundaries in child-directed speech, and do not emphasize syntactic units. 2. SYNTAX

Syntactic dimensions of maternal speech have been compared with those of child speech as mothers and their children interact in a variety of settings. There are two central issues in these studies: (1) the relationship between the syntactic complexity of maternal and child speech, as indicated by measures such as mean length of utterance (MLU); and (2) the relationship of the emergence of specific syntactic structures in children’s speech to the frequency with which those structures occur in maternal speech.

a Syntactic Complexity When mothers address their children, they consistently reduce the syntactic complexity of their speech so that the complexity of maternal and child speech is significantly correlated (Baldwin & Baldwin, 1973; Nelson, 1973; Snow, 1972). For example, Baldwin and Baldwin (1973) reported that when mothers participated in an interview with an adult, the average length of their utterances was 13.2 words, but when they played with their 2%-year-old children, their speech averaged 4.67 words per utterance. The modification of maternal speech appears to play a role in the syntactic development of children for several reasons. First, the syntactic complexity of maternal speech increases from the time children are 13 months old until they are 120 months old and probably until language development is f d y completed. In longitudinal studies increases in maternal language complexity have been observed in naturalistic settings with children from 13 to 18 months (Lord, 1975) and 13 to 24 months (Nelson, 1973), and in laboratory settings with children 30 to 60 months (Baldwin & Baldwin, 1973). Age-related increases in

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the complexity of maternal speech have also been observed in cross-sectional studies including children between 18 to 120 months (Fraser & Roberts, 1975; Gamer & Dodd, 1975; Phillips, 1973; Seitz & Stewart, 1975; Snow, 1972). Second, the increasing complexity of maternal speech may not be attributed to a shift in maternal modes of transmitting information. While the complexity of child-directed speech varies with the mode of information exchange, e.g., descriptions have longer MLUs than labels (Baldwin & Baldwin, 1973; Lord, 1975), age-related increases in language complexity occur within each of the modes (Baldwin & Baldwin, 1973). Third, while both child and maternal speech increases in complexity developmentally, the ratio between the syntactic complexity of maternal and child speech decreases (see Fig. 1). The rate of decrease is rapid and relatively stable between 13 and 28 months and slows markedly after 28 months so that the ratio of the complexity of mother-to-child speech from 30 to 60 months is approximately 1.5: 1 (Baldwin & Baldwin, 1973). This decreasing ratio suggests that as children's language ability increases and they participate more in dialogue with their mothers, mothers tailor their speech to the children's ability to comprehend more efficiently and, in so doing, provide the children with a progressive syntactic model. Fourth, the modification of maternal speech depends partially upon the language of children, since maternal speech is more complex before children utter their first words than it is when they fmt utter 2-word utterances (Lord,

4.001

t

3.001

-

N

G

21)0:1-

S

G

B

1.m Age of Child

(Months)

FIG. 1. The ratio of the syntactic complexity of maternal speech to child p c h . B, Baldwjn & Baldwin, 1973; G, Glanzer & Dodd, 1975; N, Nelson, 1973; S, Seitz & Stewart, 1975.

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1975; Phillips, 1973). Lord (1975) identified three phases in the modification of child-directed speech. First, from the time the children were 6 months until they uttered their first words at approximately 11 months, there were progressive increases in the complexity of maternal speech. Second, from the time children uttered their first words until they uttered 5 words (1 1-14 months), the complexity of maternal speech decreased to its lowest levels. Third, from the time children produced 5 words until they were 18 months old, maternal speech gradually increased in complexity. Glanzer and Dodd (1975) presented additional evidence that maternal language regulation was related to, and perhaps even regulated by, linguistic cues from children. In a cross-sectional study of 18 mothers interacting with their 10to 30-month-old children in home play sessions, the complexity of maternal speech was inversely related to the degree to which mothers dominated the verbal interaction. Within segments of mother-child dialogue consisting of 8 utterances, the average MLU of maternal speech was 3.41 when the mother contributed 2 of the 8 utterances, 3.83 when the mother contributed 4 of the 8 utterances, and 4.15 when the mother contributed all 8 of the utterances. Apparently mothers become more efficient in judging the capacity of the children to understand as the children participate more in dialogue. Fifth, the modification of maternal speech increases the probability that children will comprehend those utterances. Glanzer and Dodd (1975) reported that children whose approximate MLU was 1.47 were most likely to respond appropriately to maternal speech which was in the range of 2 to 6 words per utterance. Children whose MLU averaged 2.21 were most likely to respond appropriately to maternal utterances which were between 4 and 9 words long, and children with an MLU of 2.95 were even more likely to respond to maternal utterances which were between 4 and 9 words than were the middle group. When the complexity of maternal language greatly exceeds the complexity of the children’s language, the likelihood that the children will respond appropriately to the utterance diminished markedly, Sixth, the modification of child-directed speech is not restricted to mothers. Snow (1972) found that women who were the same age as the mothers of the children in her study, but were not mothers, reduced the complexity of their child-directed speech as well as did the mothers. Shatz and Gelman (1 973) found that the speech of 4-year-old children to 2-year-old children was less complex than the speech they addressed to their peers or to adults. Two major questions about language modification remain unanswered. First, what effect does language modification have on the rate of language acquisition? Second, what factors other than linguistic cues mediate language modification? Since language modification occurs when almost anyone speaks to children during the active phases of language learning, the results of research concerning this phenomenon should have major implications for language intervention.

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b. Syntactic Structure If children’s syntactic development is related to speech which is addressed to them, then the order in which grammatical structures emerge in child speech should be correlated with the relative frequency with which these structures occur in the language addressed to children. In a longitudinal study Brown et aL (1969) compared the relative frequency with which mothers produced three linguistic categories (prepositions, adverbial questions, and five grammatical morphemes) in their own speech to the development of those categories in their children’s speech. In general, the frequency with which the targeted linguistic structures occurred in maternal speech correlated positively to the rank order in which children began to produce them. When the children began to produce a particular linguistic form, they produced it in all phrases requiring it at about the same time, whether or not the particular phrase had been modeled previously by the mother. This suggests that the children were learning by induction of the general rule governing the use of each structure rather than by imitation. In a cross-sectional study of 18 children at three levels of linguistic development, Glanzer and Dodd (1975) compared the frequency of verb types in child speech to the frequency of verb types in maternal speech by using semanticsyntactic, or case grammar, categories. Mothers of children in the three stages tended to use the various verb categories at the same relative frequency. In the children’s speech, however, there was a significant developmental increase in the use of several verb types and a decrease in the use of nomination. The rank order correlation between the speech of mothers and children for the frequency of 15 basic verb types was .9 1 when verb frequency was averaged within and across the three groups of mother-child dyads, Therefore, the speech of mothers and their children was similar in the frequency that various verb types were used in a play setting. The studies of both Brown et al. (1969) and Glanzer and Dodd (1975) indicate that the order in which early grammatical structures emerge in child language is related to the frequency with which mothers use those utterances in child-directed speech. The correlations reported by Brown et al. were not as high as those reported by Glanzer and Dodd, but the criterion used by Brown et al. (i.e., the order in which children first used grammatical structures appropriately) was more stringent than that used by Glanzer and Dodd (i.e., the relative frequency of verb usage in child speech). It should be noted that the positive correlations reported by Glanzer and Dodd could be attributed to any of three different factors: (1) the constraints of the observational setting; (2) the mother modifying her language according to the child’s speech; or (3) the child learning from the mother. These results lend well to the interpretation that mothers were acting as linguistic models for their children, however, because the verb types used by children differed at the three levels of linguistic development while the verb types used by mothers were relatively constant.

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3, WORDORDER

In English, word order is a reliable cue to the syntactic categorization of each word in a sentence (Brown & Bellugi-Klima, 1964). English-speaking children may, therefore, learn some aspects of syntax by attending to the position of words in sentences (Slobin, 1971). In some languages where the order of words in adult-adult speech is not correlated with syntactic categories, adults may speak to children with a relatively fured word order, making word order a potential cue for learning syntax. Buium (1974) reported that while an adult Hebrew speaker used a relatively free word order while interacting with an adult, he typically used a subject-verb-object (SVO)word order while interacting with his 2-year-old daughter. If one function of word order is to accentuate syntactic structure, children ought to respond to a fured word order by producing a fured word order. Brown (1973) notes that studies of children's emerging word order in different languages provide contradictory data on this matter. In French, word order is an important syntactic device, yet variations on normal word order are not uncommon in the speech of young French-speaking children (Sinclair-de-Zwart, 1971). Bowerman (1973) studied the emerging word order of two young children learning Finnish, a language in which the word order is not an important syntactic device, although adults often use SVO. She found that the two children behaved differently. One child reflected the dominant adult SVO word order in both 2- and 3-word utterances, but the other child used OV and SOV more often than SVO. While word order may not be an effective parental strategy in all languages, the correlation of word order to syntactic categories in English makes it an obvious source of syntactic information for children learning that language. 4. SEMANTICS

At least two characteristics of child-directed speech have been identified as functioning specifically as devices for reducing semantic complexity. These are vocabulary constrictions and repetition. Vocabulary constriction is typically measured by the type:token ratio (Tl'R)-the ratio of the number of words in a conversation that are spelled differently (Types) to the total number of words in the conversation (Tokens). A low TTR (< SOO) indicates that a segment of conversation contains a relatively limited vocabulary and a narrow semantic domain, while a high TTR (>.500) indicates that the segment of speech is composed of an extensive vocabulary and that a very few words are repeated, Both Broen (1972) and Phillips (1973) found that the TTR of maternal child-directed speech is sigtuficantly lower than the TTR of their adultdirected speech. Phillips (1973) found that in the same free play setting the TTR of

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speech directed to 28-month-old children was significantly higher than the TTR of speech directed to 18-month-old children and to 8-month-old children. Although the proportion of function words and content words was approximately the same in speech to 18- and 28-month-old children, mothers used a greater variety of verbs and modifiers when speaking to their 28-month-old children. Therefore, according to various measures, the semantic complexity of maternal speech increases as children develop. Further evidence that semantic complexity is restricted is that most adults tend to use the same words while talking with young children, such as the verbs: look, see, come, go, put, take, find, and give (Broen, 1975; Phillips, 1970). The TTR of child-directed speech is low partly because child-directed speech is extremely repetitive. Estimates of the amount of repetition in maternal speech range from 9 to 43% (Benedict, 1975; Broen, 1975; Friedlander, Jacobs, Davis, & Wetstone, 1972; Kobashigawa, 1969). Repetition is a very compelling strategy for parents, since mothers become frustrated and angry when they attempt to inhibit their repetitions (Benedict, 1975). Most repetitions addressed to children 9-16 months of age are commands and implied demands. The repetition of commands both enhances the probability that the children attend to the utterance and enables the children to respond correctly to more parts of the utterance (Benedict, 1975). Repetition may, therefore, facilitate early language comprehension. Repititions may be either exact or modified in a variety of ways. In addition to facilitating comprehension, modified repetitions may provide children with linguistic information, as in the following example of a mother’s speech: See the doll, Look at the pretty dolly. Watch the dolly’s eyes. Look at the dolly’s eyes. See her eyes. See her pretty hair. See the dolly’s hair. Where’s the dolly’s nose? Where’s her nose? That’s her mouth. Where’s her nose? That’s Jeffrey’s nose. Here’s the dolly’s nose. That’s the dolly’s nose. [From Broen, 1975, p. 121

In this example, the verbs watch, look, and see were all used with essentially the same verb phrase, thus potentially defining the verb class. Likewise, the noun phrase the do& was substituted repeatedly by the pronoun her, providing a systematic example of pronominal substitution to the child (Broen, 1975).

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76 5. SUMMARY

Child-directed speech contains fewer broken sentences, fewer disfluencies, and is slower, with longer pauses between sentences than speech directed to adults. The MLU of maternal language is correlated with the MLU of child language and increases gradually as children grow older. In languages where word order is relatively free, social agents may use a fixed word order when addressing children. Furthermore, most social agents use the same high frequency words repeatedly and reduce the range of their vocabulary when they speak to children. The specific effects that social agents have on language acquisition by making linguistic modifications in their speech are not yet clear. A number of possible effects have been considered: children apparently comprehend speech most efficiently when it is only slightly more complex than their own speech; the use of a relatively fixed word order reduced the amount of variation in childdirected speech and may therefore simplify the task of comprehension; the most frequently occurring syntactic categories in speech directed to children are learned the earliest; repetition facilitates comprehension, while modified repetion provides information about the replacement of linguistic forms. There is some support for the hypothesis that the linguistic strategies of social agents and children are reciprocally related. When social agents modify their speech they apparently respond directly to the linguistic behavior of children. Yet other behavioral indicators may play an important role in language modification, some of which may be crucial to an understanding of the differences that may exist in the interactions between social agents and mentally retarded children. C. Functional Aspects of Maternal Speech

The following section will identify and discuss some parameters of discourse which parents use to respond to their children’s language (Response Variables) and to provide their children with verbal stimulation (Stimulus Variables). The strategies considered in this section operate in conjunction with those language parameters which were discussed previously. For example, Lord (1975) found that the MLU of maternal language teaching utterances was significantly less than the MLU of their total language sample, while the MLU of maternal responses to children’s utterances was less than the MLU of their language teaching utterances. 1. RESPONSE VARIABLES

a. Expansion

Expansion is perhaps the most complex pattern of verbal interaction between a parent and a child and superficially appears to be an obvious syntactic teaching

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strategy. Children initiate the sequence of expansion by producing a grammatically incomplete utterance such as “Eve lunch”; mothers respond by expanding the utterance into a well-formed sentence which preserves the child’s word order such as “Eve is having lunch”; finally, children may terminate the sequence by imitating the expanded utterance. Brown and Bellugi-Klima (1964) reported a 30% rate of expansion in mothers’ speech to two very young children (MLU 1.O to 2.0). Other research indicates that there is considerable variability among mothers in the extent to which they use expansion, and that rates of expansion change with the developmental level of the child. For example, in a study of two young children, Friedlander et al. (1972) reported that none of the utterances directed toward a child in the babbling stage could be characterized as an expansion, while 3.7% of the mother’s utterances and 8.2% of the father’s utterances directed toward a child who was using words were classified as expansions. Nelson (1973) found that only a little more than 1% of all maternal utterances to 24-month-old children could be classified as expansions. The highest rate for any mother in her sample was 996, and 4 out of 18 mothers produced no expansions at all. Seitz and Stewart (1975) reported that of the utterances produced by mothers of 24-month-old children during 15-minute play sessions, 2.8% were expansions, while almost none of the utterances produced by mothers of 54-month-old children could be classified as expansions. Data concerning the relative effectiveness of expansion at improving syntactic development have also been inconsistent. Slobin (1968) observed that the imitations children produce after their utterances have been expanded are often more grammatically complex than their other utterances. Cazden (1965) reported a study in which experimenters systematically expanded the ungrammatical utterances of 29- to 37-month-old children, 40 minutes per day for 3 months. The expansion treatment did not result in any increases in the rate of syntactic development. More recently, K. E. Nelson, Carskaddon, and Bonvillian (1973) replicated Cazden’s procedure with 32- to 40-month-old children but also reformulated children’s grammatical utterances into different grammatical forms which retained the original semantic intention. After 22 sessions, subjects receiving this treatment showed a significant increase in the rate of syntactic development when compared with subjects who had received no experimental intervention at all. The studies by Cazden and by Nelson et al. may not accurately reflect the influence of expansion on syntactic development within natural settings where expansions are seldom employed in massed sessions, and the frequency of expansion is considerably lower. In addition, neither study used mothers to expand children’s utterances. Since the strategy of expansion requires that language models reflect the semantic intention of the child in the expanded utterance, mothers may more accurately preserve their children’s intentions in expansions.

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K. Nelson (1973) reported that the rate of maternal expansion at 24 months was significantly correlated with children’s ability to comprehend at 21 months, and with children’s vocabulary and labeling at 24 months, but was not correlated signifkantly with children’s vocabulary at 30 months. These findings indicate that maternal expansions may influence early semantic development positively. On the other hand, Seitz and Stewart (1975) found that the rate of maternal expansion at 24 months correlated positively with children’s rate of spontaneous imitation and correlated negatively both with children’s MLU and frequency of elicited utterances at 24 months, indicating that expansion may be associated with immature language development at 2 years. These conflicting fmdings can be resolved only by collecting and analyzing larger samples of speech at more closely spaced intervals and by assessing possible variations in strategies of expansion. At present, it appears that if expansion has any effects on language development, the magnitude of these effects varies among children and between developmentalperiods. b. Imitation There has been less research on parental imitation than on expansion even though the relative rates of parental imitation appear to be roughly equivalent to the rates of expansion. Friedlander et al. (1972) found that 6.2% and 9.4% of the speech of parents directed toward their 12-month-old child could be characterized as exact imitations; both Nelson (1973) and Seitz and Stewart (1975) reported that about 4% of the utterances directed toward 24-month-old children were exact imitations, and Seitz and Stewart (1975) reported that 1.1% of maternal utterances directed toward 54-month-old children were exact imitations. Nelson (1973) found that the rate of maternal imitation of 24-month-old children was correlated negatively with the ages at which children both first produced 10 words and first produced 10 multiword utterances. These findings provide marginal evidence that at certain stages of development parental imitation is associated with immature language production. These correlations shed very little light on the role of parental imitation, however, since parents apparently imitate more frequently in the earliest stages of language development than they do at slightly later stages. Data are needed to determine the relative frequency of imitation when children are between 12 and 24 months old to delineate more precisely how this strategy may be related to early indices of language development. It is also possible that different types of parental imitation may elicit different responses from children and, consequently, serve different functions in the process of language acquisition. It is possible that exact imitation serves to interpret or clarify the child’s utterance, while interrogative imitations (repeating a child’s utterance with the mode changed from declarative to interrogative) elicit more elaborate utterances or teach the child the interrogative transformation. The lack of data concerning parental imitation

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currently makes it impossible to determine their functional significance in the development of language.

c. Interpretation Not only are children’s earliest utterances ungrammatical and incomplete statements, but perhaps most characteristically they are unclear and often unintelligible. Several anecdotal accounts describe parents as being quite motivated to interpret the intentions of their children’s vocalizations (Ryan, 1974). Interpretations may be based on intonation patterns, accompanying gestures or states of the child, as well as the circumstances of the utterance such as the presence or absence of particular objects or people. Whether children use vocalizations systematically or intend to communicate information to an adult by vocalizing may be much less significant than the fact that parents are willing to attribute intention and actively interpret the vocalizations of children. Research is needed to determine what specific cues parents use for interpreting their children’s utterances and the effects that interpretation has on language development. It seems likely that when children first begin to babble, parental interpretations of these babblings teach children the communicative potential of the vocal mode. As children begin to use words, it becomes increasingly important that specific vocalizations can convey specific information. At this stage, the accuracy of parental interpretations may become a critical factor for further linguistic progress. d. Correction It is difficult to distinguish between the strategies of correction and reinforcement, for children may interpret parental correction as a rejection of their verbalization and, consequently, a source of negative reinforcement. The following considerations of parental corrections, however, will not view this strategy in terms of its effects on the child, but rather in terms of the apparent intention of the adult. Expansion, a strategy which could be characterized as a grammatical correction, has been discussed previously. There are no reports in the literature of parents correcting the syntactic structure of children’s speech in a more direct or didactic fashion. While parents apparently correct many semantic inaccuracies (Brown 8~ Hanlon, 1970; Nelson, 1973), they also tolerate a considerable amount of inaccuracy in child speech, an approach which is consistent with the strategy of interpretation. Nelson (1973) defined rejection as a verbal indication that the words or actions of children were inappropriate, e.g., “No, it’s not a doggie, it’s a kitty” (p. 68). While not all rejections as defined by Nelson can be classifted as corrections, a large proportion can be. She found marginally significant negative correlations between the rate of maternal rejection when children were 13 months and four indices of early language development. In addition, there was a

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significant negative correlation between the maternal rate of rejection at 24 months and children’s MLU at 24 months and a marginally significant positive correlation between rejection at 24 months and children’s vocabulary at 30 months. If the rate of rejection remained stable between 24 and 30 months, then Nelson’s findings indicate that the effects of correction are dependent upon the developmental level of the child. Moerk (1974) reported that the rate of maternal correction in speech to 2- to 5-year-old children decreased from 10.5% when children were producing 2 mean syllables per utterance, to less than 1% at 4.8 mean syllables per child utterance. Current understanding of the role of parental correction in language acquisition is quite limited. Research is needed to determine the relationship between the frequency of inaccurate utterances in child speech and the rate of parental correction as well as what criteria parents use for correcting their children’s language.

e. Reinforcement The strategy of reinforcement requires that parents respond selectively to children’s speech such that well-formed utterances are followed by positive responses while primitive or incorrect utterances are followed by negative responses. The problems of identifying parental reinforcement in the natural environment include defining positive and negative parental responses and determining what parents perceive to be appropriate verbal responses on the part of the child. Positive parental responses may include approval, appropriate response to children’s instrumental utterances, or other parental behavior which has yet to be identified in terms of its reinforcing value (e.g., sustained parental interaction). Negative parental responses, on the other hand, may include a failure to respond to the child’s utterance, disapproval, or any other factors which the child may interpret as being undesirable. Since there are individual differences among children in the rate and progress of language development, it seems reasonable that there might be substantial differences among parents in what they consider to be well-formed child utterances. Consequently, the problem of identifying patterns of parental reinforcement is extraordinarily complex, and it must be explored in terms of individual styles of parent-child interaction. No observational study of parental reinforcement has yet been conducted which deals adequately with the methodological problems of individual differences. Nelson (1973) reported that 7% of maternal speech could be classified as approval when children were 13 months old, while only 2% of child-directed speech expressed approval when the children were 24 months old. Expressions of approval were not contingent upon the syntactic accuracy (using standardized criteria) of the utterances but, rather, were contingent upon the truth value or semantic appropriateness.

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Brown and Hanlon (1970) reasoned that if parents exert selection pressure on children to adopt well-formed grammatical structures, they should respond appropriately to well-formed constructions and inappropriately to primitive constructions during those transitional periods when children are vascillating between the use of the well-formed and primitive utterances. The protocols of three children during two transition periods were analyzed for four different grammatical structures (Yes-No; Wh-questions; tag questions; and negatives). In general, no evidence was found that the appropriateness of parental responses could account for the transition from primitive to well-formed grammatical utterances. Both the Nelson (1973) and Brown and Hanlon (1970) studies must be viewed as preliminary investigations of verbal reinforcement, since no attempt was made to discuss individual differences among parent-child dyads. For the reasons discussed previously, individual differences may not be ignored while studying reinforcement. In addition, the study by Brown and Hanlon was based on an outmoded theoretical framework (Watt, 1970) and, consequently, is difficult to interpret in light of current theoretical developments. Nelson limited her analysis to the frequency of parental approval and disapproval, which is a narrow interpretation of reinforcement, and did not report what kinds of utterances mothers were approving. Furthermore, in both of these studies no attempt was made to differentiate between correction and reinforcement.

f: Responses to Children’s Questions In a cross-sectional study of 174 mother-child dyads in which children were between the ages of 2%and 5 years, Baldwin and Baldwin (1973) reported that nearly 60% of all maternal utterances could be coded as responses to children’s questions. While there was no significant variation based on the age of the children, individual differences among the mothers were large, ranging from 0 to 92%. In addition, no significant developmental differences were found when responses to questions were classified as either direct responses (exact answer to a previous utterance), peripheral responses (indirect response to a question: e.g., C: What is that? M: Ask your father), or responses with no information (e.g., “What did you say?” or ‘What do you think?”). The high rate of response to questions in maternal speech indicates that this discourse pattern may influence children’s rate of language development. An exploration of the syntactic and semantic parameters of maternal responses to questions might provide some information regarding their strategic value. g. Summary The rates at which various response parameters occur in maternal speech and the changes in these rates which are associated with the chronological age or linguistic development of children have been reported. Definitive evidence

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regarding the function of these parameters for language development is not yet available. For example, fmdings regarding the effects of expansion on syntactic development have been contradictory. In part, discrepant findings may be attributed to possible differential effects of expansion at various levels of development, as well as to the general failure to defme expansion in precise terms. Some evidence that the effects of maternal response parameters may be associated with the developmental level of the child was found with correction. While the rate of maternal correction was correlated negatively with early indices of language maturity, positive correlations were found at later stages of development. Studies of the function of reinforcement have been restricted primarily to exploring the effects of reward or praise and have not attempted t o determine what criteria parents may use for reinforcing language. Defined as approval, reinforcement was found to be related to the content of children’s utterances rather than to the appropriate formation of syntactic structure. Two maternal response parameters which appear to have didactic value have received only limited attention. There has been some discussion of the role of interpretation in language development, but no data to support these speculations. While there is some indication that response to questions may be one of the more frequent maternal response parameters, the available data are not specific enough to support any speculation regarding the didactic value of this response parameter. The fact that the rates of various response parameters in maternal speech are related to children’s linguistic development provides additional evidence that social agents adapt their speech to the needs of the language learner. Further research is needed to explore the precise nature of these interactive functions. 2. STIMULUS VARIABLES

Parents may either request or demand certain behavior, give information, or seek information from children. In the following discussion, some of the linguistic and informational components of these three classes of verbal stimulation will be considered as they relate to language development.

a. Behavior Requests Adults use imperatives, questions, and declarative statements such as instructions or directions in attempts to influence children’s behavior. Most behavior requests cannot be categorized as commands in the strict sense, because the illocutionary mood is one of friendly coaxing rather than anger or insistence (Baldwin 8c Baldwin, 1973; Broen, 1975). Buium, Rynders, and Turnure (1974) found that imperatives constituted 8.8% of maternal utterances directed toward 24-month-old children, while Baldwin and Baldwin (1973) found that behavior requests of all kinds accounted for 15.8% of the speech addressed to 2%-yearolds to 9.8% of the speech addressed to 5-year-olds with a mean rate of behavior requests for all child-directed speech of 13.9%. The MLU for behavior requests

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was slightly higher than the MLU of both the total statements and total questions. Commands or imperatives, however, had lower MLUs than the average behavior request (Baldwin & Baldwin, 1973). The imperative is a bare verb phrase in which the verb is unmarked for number and tense and the sentence has no subject, so that it should provide the language leamer with information regarding the basic relationships that occur among the words in the verb phrase. In addition, imperative sentences are frequently embedded in longer sentences when mothers repeat their commands (e.g., Benedict, 1975), potentially providing children with information regarding the segmentation of speech and the process of embedding: e.g., “See the doll.” “Can you see the doll?” (Broen, 1975, p. 11). While this analysis seems logical, Newport, Gleitman, and Gleitman (1975) found that the more frequently mothers produce imperative utterances, the more slowly normal children learn to produce both noun phrase constructions and auxiliaries. Although affirmative imperatives are correlated with delayed rates of linguistic development, negative imperatives are not (Newport et aL, 1975). One explanation for the differential effects of these two forms is that the affirmative imperative never maps clearly into the nonlinguistic context, while the negative imperative has a very clear referential context: “e.g., one says ‘Throw the ball’ precisely when the child is not throwing the ball, and ‘Don’t throw the ball’ when he isyy(Newport et al., 1975, p. 115). In addition, Buium et al. (1 974) found that maternal speech addressed to 24-month-old children with Down’s syndrome contained a significantly higher percentage of imperatives than maternal speech addressed to nondelayed children. Although imperatives may elicit appropriate responses from very young children, the children may react primarily to the tone and nonlinguistic aspects of the utterance, and fail to attend to the linguistic content. Consequently, the imperative may be useful in prompting children to act, but may be a very poor construction for teaching the child the relationship between linguistic structure and environmental events. b. Information Requests Estimates of the relative rates of parental questions range from 10% of the speech addressed to 12-month-old children (Friedlander et aL , 1972) to 32% of the speech addressed to 13-month-old children (Nelson, 1973), and 37% of the speech addressed to children between the ages of 2 and 5 years (Baldwin & Baldwin, 1973; Nelson, 1973). The frequency of questions in maternal speech decreases gradually after the children reach 30 months of age. Nelson (1973) found that the percentage of questions in maternal speech to 13-month-old children correlated significantly with children’s comprehension at 21 months and correlated marginally with children’s rate of acquisition between 13 and 24 months. The frequency of questions in maternal speech to 24-month-old children correlated positively with children’s comprehension at 21 months and also with children’s MLU and vocabulary at 30 months.

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When a speaker addresses a question to a child and the child fails to respond, the speaker typically rephrases the question by changing it from an elaborate question to a simple question (e.g., from “What is that?” to “Is that a ball?”) or answers the question himself (Berko-Gleason, 1973). Such sequences should provide children with information concerning the relationship of one interrogative form to another or the relationship between the declarative and interrogative forms (Berko-Gleason, 1973; Broen, 1975).

c. Provide Information The content of speech addressed to children up to 24 months of age may be classified according to whether it refers to objects in the immediate environment (i.e., naming or describing attributes or actions of objects, or relating children and objects such as in questions or commands) or to the child (i.e., making requests, describing actions or talking about what the child is doing, had done, or should do) (Nelson, 1973). Speech referring to objects is called referential speech, while speech referring to the child is called social speech. Nelson (1973) found that mothers tended to use slightly more referential speech when children were 13 months old and that referential speech was positively correlated with several indices of early language development. When the children were 24 months old, mothers tended to use equal amounts of referential and social speech. At this point, referential speech was negatively correlated with language development. On the other hand, social speech was negatively correlated to indices of language development at 13 months, while it was positively correlated to language development at 24 months. Nelson’s data suggests that for very young children, the more directly maternal speech related to immediate context, the easier is the language learning task. Mothers may employ a variety of nonverbal cues to clarify the relationships between speech and context, for example, pointing or deixis. Newport et al. (1975) reported that during the first year of language development the frequency of deictic utterances in maternal speech, naming an object while pointing to it, correlated significantly both to vocabulary development and to noun phrase elaboration. When children process language in conjunction with nonlinguistic events, the meaning of the language is easier to determine and language growth is, consequently, accelerated. The extent to which parents spontaneously use nonverbal gestures to aid in this process has not yet been determined. Baldwin and Baldwin (1973) found that specification, which is defined as the use of gestures or complement verbal information about location or selection (e.g., ‘‘I want this one,” or “Go over there”) occurs in 12% of the speech directed toward children between 2% and 5 years. It seems likely that, if all forms of nonverbal communication were considered, researchers would find that a much larger percentage of child-directed utterances in the first few years of language development are accompanied by nonverbal cues to meaning.

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There appears to be a progressive increase in the cognitive complexity of referential speech directed to children as they grow older. The rate of labeling decreases from 40%at 13 months to 22%at 2% years and 13%at 5 years; while description, which seldom occurs at 13 months, increases from 7%at 2 years to 40% at 2% years and 60%at 5 years, and explanation remains between 3 and 5% between 2% and 5 years (Baldwin & Baldwin, 1973; Nelson, 1973). Social speech directed to children has not been studied for developmental changes in cognitive complexity, Further research is needed to determine whether parents express or describe needs, feelings, behavioral information, and social events or relationships at different rates depending on the age of the child.

d. Summmy When social agents initiate a linguistic exchange with children, their speech may be categorized as consisting of behavior requests, information requests, or informational statements. Very little data exist concerning the relative effects of such linguistic stimulation on specific aspects of language acquisition. It does appear that the form used to express varying content may have critical effects on language acquisition. Among behavior request forms, for example, positive imperatives are correlated with delayed rates of language development while negative imperatives are not. Most information requests are in question form and are thought to provide linguistic transformation information to children, especially when social agents answer their own questions as they commonly do. It appears that for children at the earliest stages of language acquisition informational statements are most effective when they label a referent which is present in the environment, since referential speech on the part of mothers is positively related to children’s speech measures at 13 months, although it is negatively related to children’s speech at 24 months. Similarly, deictic speech is positively related to vocabulary development and noun phrase development during the first year of language acquisition. The most convincing evidence that stimulus variables in the speech of social agents are reciprocally related to children’s behavior is that the forms of verbal stimulation in maternal speech vary with the developmental progress of children. The rate of information requests in maternal speech increases until children are 30 months old and gradually decreases thereafter. Similarly, the rate of labeling in maternal speech declines during the preschool years while the rate of descrip tion and explanation increases. D. Child Language Learning Strategies

While the role of the social agent has been largely neglected in theories of language development, the preceding review indicates that language development cannot be understood without considering the behavior of social agents, Further-

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more, this behavior cannot be accounted for in simplistic theoretical terms. The strategies of social agents seem to be highly responsive to the behavior of language leaming children, since a large portion of the speech of social agents can be classified as responses to children’s speech and since modifications of child-directed speech seem to depend partially on the speech of the child involved. With very few exceptions, studies of language acquisition have focused only on the characteristics of children’s linguistic behavior without considering the effects of children’s behavior on language models. In the following section, those aspects of children’s speech which might have a strategic effect on language models and thus help children to master the elements and rules of their native language are considered. The review focuses on how children’s strategies are used during social interaction, how strategies might effect language acquisition, and how these strategies change as development progresses. 1. IMITATION

Although imitation has often been suggested as critical to language acquisition, especially in behaviorist theories (Sherman, 1971), the rates of spontaneous imitation reported in five observational studies never exceeded 45% of children’s total utterances and, typically, were in the range of 10 to 2% with vast individual differences (Bloom, 1974; Brown & Bellugi-Klima, 1964; Moerk, 1974; Nelson, 1973; Slobin, 1968). Bloom (1974) reported that out of a sample of six 20-month-old children who were within the same range of language development, three were nonimitators (9% of their utterances were imitations) and three were imitators (33% of their utterances were imitations). Over a period of 20 weeks, those who were high imitators continued to be high imitators, while those who were low remained low. In addition, the rate of spontaneous imitation decreases developmentally (Bloom, 1974; Slobin, 1968) so that normally developing 3-yearsld children seldom imitate spontaneously (Moerk, 1974). These observations complement Nelson’s (1973) finding that children’s rates of spontaneous imitation at 24 months correlate negatively with several indices of language development. It appears that before children attain language maturity, spontaneous imitation becomes a relatively inefficient language learning strategy and its rate decreases markedly. Several investigators have analyzed the grammatical complexity of children’s imitative utterances to determine if those utterances are more progressive than spontaneous speech. Ervin-Tripp (1964) found that for four out of five children between the ages of 22 and 34 months the grammatical rules governing spontaneous speech also accounted for imitative utterances. She concluded that imitative speech was not grammatically progressive and that imitation was not a functional process in the acquisition of grammar. Similar conclusions have been drawn from studies of children’s elicited imitations. When children are required to imitate an utterance that is more complex than their spontaneous speech,

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they tend to simplify the imitated utterance so that its grammatical complexity does not exceed the complexity of the children’s spontaneous speech (Brown & Fraser, 1964;Miller, 1973;Scholes, 1969). Slobin (1968), on the other hand, examined two children’s imitations of parental expansions a d found that most of these imitated utterances were more complex than the children’s original utterances. He argued that, although children’s imitations may not be grammatically progressive in every instance, there are selected situations, such as that triggered by a parent’s expanded response to a child’s utterance, when imitation may result in a progressive grammatical utterance. Bloom, Hood, and Lightbown (1974) also reported evidence that children’s imitations are selective and grammatically progressive. Protocols from six children during the period in which their language complexity increased from an MLU of 1 .O to an MLU of 2.0 were divided into utterances which were imitated only, utterances which were produced spontaneously only, and utterances which were both imitated and produced spontaneously. First, the children did not imitate words which they used spontaneously, and words they imitated at any one time were not produced spontaneously. Words that were imitated tended to be used spontaneously at a later time. Second, children imitated only semanticsyntactic categories which they already knew something about, but tended not to imitate semantic-syntactic categories which they frequently produced in their spontaneous speech. In summary, children may use imitation as a strategy for acquiring grammatical and lexical structure, although the efficiency of imitation as a strategy may be restricted to selected dimensions of language at certain levels of language maturity. An important research problem is to delineate the determinants of selective imitation. Bloom et al. (1974)suggest that children actively select those words and structures in speech which they are in the process of learning and that imitating helps them to represent the linguistic information internally, a use of imitation described by Piaget (1962). Slobin (1968) suggested that parental interaction may partly account for selective imitation. While the overall rate of spontaneous imitation among children studies by Slobin was lo%,they imitated nearly 50% of their parents’ expansions. 2. COMPREHENSION

A number of different types and degrees of comprehension have been identified in recent research and appear to be used by children as strategies for learning language. As MacNamara (1972) suggested, it may be that children first comprehend the speaker’s meaning and then relate the meaning to specific linguistic forms. Even before children reach the single-word stage, they may use contextual cues and paralinguistic forms to “comprehend” a speaker’s intentions. Lewis (1951) reported that at 8 months, children react to different phonetic forms having the same intonation patterns in the same situation with

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the same response. Comprehension, at this stage, is the result of the interaction of intonation and situational cues, but is independent of the phonetic form. A number of studies indicate that during the early stages of language acquisition children depend on a combination of linguistic and contextual information to decipher new lexical and syntactic forms. Clark (1973) identified both linguistic and nonlinguistic comprehension strategies which children from 1?4to 5 years used when they were tested for comprehension of locative prepositions. Children were instructed to put a toy animal either in, on, or under one of six reference point objects (RPs). An examination of error data indicated that the younger children seemed to be using two simple, ordered strategies for comprehending instructions based on the context rather than on any specific knowledge of the terms: (1) If the RP is a container, x is inside it; (2) if the RP has a horizontal surface, x is on it. If the RP was a container, younger children acted as if all instructions contained in. When the RP had a supporting surface, the children acted as if all instructions contained on. Slobin (1971) proposed that one comprehension strategy used by children is based on the linguistic parameter of word order. For example, some researchers have found that young children interpret passives like “The boy was pushed by the girl” as if they were actives, like “The boy pushed the girl” (Bever, 1970; Fraser, Bellugi, & Brown, 1963). It appears that these children seek out nounverb-noun sequences in the speech they hear and then assign them the semantic roles of action-agent-object. Research is needed to further identify comprehension strategies of the sort described above. One question that needs to be answered is, what determines the strategies children use? For example, does a child treat passives as if they were actives because he is generalizing from the more commonly used active sentence form, or because agentive relations are more cognitively salient than object relations (Clark, 1973)? Another important question is, to what extent are specific strategies characteristic of all children and to what extent are they individualistic? 3. PRODUCTION

There are individual differences in the verbal forms children use and these differences may reflect different communicative strategies. Nelson (1 973) identified two productive styles, referential and expressive, in the speech of children. Referential speech was object-oriented with over 50% of it consisting of names or labels for objects. Expressive speech was more self-oriented, consisting of more references to personal needs and other social affective content. Children who used referential speech showed more rapid acquisition rates at the end of the 50-word period, and used more telegraphic speech. Children who used expressive speech showed more steady rates of acquisition, were younger when they used 10 or more phrases, and used longer, more grammatically complete

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phrases. By age 2 there were no differences in MLU between the two groups, but referential children had larger productive vocabularies. It appears, then, that children formulate different hypotheses about the content to which speech normally applies and use these hypotheses to establish their own modes of communication. In a longitudinal study of four children with MLUs progressing from 1.0 to 2.5, Bloom et ul. (1975) found two different systems of semantic-syntactic structure when MLUs were less than 2.0. Two of the children encoded verb relations and possession primarily with pronouns: “the pro forms ‘I’ or ‘my’ as agent or mover, ‘it,’ ‘this one,’ or ‘that’ as affected object, ‘my’ as possessor, and ‘here’ or ‘there’ as place” (Bloom et ul., 1975, p. 18). The other two children coded the same relations with nominal forms, so that, “ ‘Mommy,’ ‘Daddy,’ ‘Baby,’ ‘Kathryn,’ etc., formed a grammatical category agent” (p. 19). Bloom et ul. suggested that the two systems reflect the use of different strategies for syntactic encoding. In the first, children combine a single word with various other words, using it like a formal marker (as in “fEit,” “use it,” etc.); in the second, children form hierarchical combinations of categories of words. In some ways, the strategies identified by Nelson (1973) and by Bloom et ul. (1975) are as much comprehension strategies as they are production strategies. The authors assume that the linguistic forms in a child’s speech reflect the approaches that the child brings to the task of comprehending speech. “The choice of strategy (if there is a choice) as children begin to use syntax would appear to be the result of complex interactions between cognitive development and linguistic experience” (Bloom et al. , 1975, p. 35). Other aspects of production may serve the child more directly as techniques for improving his language skills. Nelson (1973) pointed out that children who talk a lot may be actively practicing phonetic production or testing their conceptual domains against those of the language users around them. She found that the mean number of utterances produced by 20-monthsld children during a 20-minute play period was positively related to age at 50 words and at 10 phrases, and to rate of acquisition. It may be, then, that the more a child talks, the more he learns about talking, although it may also be that children who learn faster talk more.

E. General Summary and Discussion We have proposed that language development is rooted in earlier forms of communication; that children and adult social agents use interactive strategies which aid in the development of children’s communicative skills in general and their language skills in particular; that the strategies of children and of social agents are reciprocally related; and that learning and teaching strategies change with development.

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To some extent, the preceding review supports each of these hypotheses. In the preverbal period infant crying, vocalization, smiling, and other expressive behavior help to establish and maintain reciprocal interactions between mother and child. Mothers, for example, are more likely to vocalize to their infants immediately after the infants vocalize than at any other time. Besides engaging mothers’ attention, such infant behavior can provide information and, depending on the sensitivity and responsiveness of the mother, lead to more effective forms of communicative exchange. When mothers are highly responsive to crying during early infancy, their children cry less and use more advanced communicative behaviors later in infancy, Mothers of young infants frequently initiate action sequences as they feed, bathe, dress, and play with their infants, and within the context of these routinized interactions children may begin to learn the significance of language as mothers use particular words and phrases to mark parts of the sequence. After children begin to use verbal forms of communication, social agents modify their speech to children in a variety of ways which may have strategic effects on the process of language acquisition. Whether social agents are responding to children’s utterances or initiating dialogue, their child-directed speech is simpler and more grammatical than speech to adults. The degree to which social agents adjust their child-directed speech is at least partially dependent on the linguistic behavior of the child and changes as the child develops. Given that all child-directed speech is modified, there are a variety of forms it can take. Social agents may expand, imitate, interpret, correct, reinforce, or attempt to answer questions when responding to their children’s utterances. When initiating conversation, social agents use language to make behavior requests, information requests, or informational statements. Each of these different usages and forms may either aid or impede the language learning process, and it appears that the relative effect of any linguistic behavior depends directly on the developmental level of the child. For example, correction seems to have a negative effect on language learning for children up to 24 months old, but may have a positive effect at later ages. Similarly, labeling objects in the environment to provide information to children seems to be a highly effective strategy for 13-month-old children but is negatively correlated with language development for 24-monthold children. In general, social agents appear to be responsive to the changing needs of children that are implied by such data. The rate of labeling, for example, decreases in maternal speech from 40% at 13 months to 22% at 2% years to 13%at 5 years. Children, too, use a variety of cognitive and interactive strategies for language acquisition, strategies which differ from child to child and across developmental stages. Some children use imitation to aid in the acquisition of grammatical and lexical structure, although the efficiency of this strategy may be limited to selected dimensions of language at certain levels of language maturity.

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Strategies for both comprehending and producing speech have been identified in recent research, but we know almost nothing as yet about how such strategies are related to the behavior of social agents. Research into the social processes involved in language acquisition is in an embryonic state, and the least well-understood dimension concerns the nature of the relationship between the strategies of the social agent and those of the child. The most convincing evidence for reciprocity in the use of strategies is the existence of systematic changes in maternal speech as children grow older. The MLU of maternal speech increases as the MLU of child speech increases, and the ratio of the MLU of maternal speech to the MLU of children’s speech declines as children’s contribution to dialogue increases. Nearly all of the maternal strategies reviewed show either gradual increases in frequency or decreases in frequency, while a few strategies increase to a point and then begin to decline. How and why these systematic changes occur can only be determined through research which focuses on characteristics of both maternal speech and child speech in the course of mother/child dialogues.

111. IMPLICATIONS OF THE ROLE OF THE SOCIAL AGENT FOR LANGUAGE INTERVENTION

A. Communicative Match

’

The review of the social processes associated with language development indicates that many aspects of the linguistic and communicative behavior of the social agent are functionally related to the development of language. This relationship cannot be characterized adequately in terms of imitation, modeling, reinforcement, or any other constructs which have been generated by associationist theories of learning. While such processes do play some role in language development, they fail to account for the entire range of social behavior which occurs throughout the course of language development. Rather this relationship appears to be one in which the behavior of the social agent is matched to the communicative competence of the child, Most relevant aspects of the social processes associated with language development can be characterized in terms of one or both of two general types of communicative match. In the first type of match the major function of the behavior is to establish intersubjectivity between the language learner and the social agent. At the most primitive level, intersubjectivity is established by the development of reciprocal patterns of behavior such as the synchronous movements of infants to the intonational pattern of speech (Condon & Sanders, 1974) or gaze coupling between mothers and their children (Jaffe etal., 1973). At higher levels, intersubjectivity may be established by mothers responding

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promptly to infant crying (Bell & Ainsworth, 1972) or by mothers approving of children’s speech proposals on the basis of semantic rather than linguistic criteria (Nelson, 1973). The beneficial effects of these latter two behavior patterns on the development of communication are contrary to behavioristic principles which would predict that these types of parental responses should increase the frequency of inappropriate behavior (e.g., crying or inadequate syntactic development). These results seem more logical, however, if they are interpreted as the mothers’ responding to the intended function rather than the specific form of the behavior. To respond to children’s intention, mothers must develop a sensitivity to the children which transcends the formal dimensions of their behavior. Likewise to elicit a more highly differentiated response from mothers the children must distinguish between their own intention, the form of behavior which they use to transmit that intention, and the reaction of social agents to that behavior. In the development of communication and language the intersubjective match between children and social agents mediates the transition between function and form. The second type of match is one in which the formal aspects of the communicative behavior of the social agent are modified to resemble the communication forms of the child, thus providing the child with the optimal conditions for learning the formal aspects of communication. For example, social agents reduce the complexity of the linguistic parameters of their speech until it is approximately one and one-half times the complexity of the form of the children’s language. When social agents achieve this ratio of complexity, children develop syntax rapidly. This phenomenon is consistent with observations that environmental events are most effective in enhancing cognitive development when they match children’s capabilities (Hunt, 1961; Piaget, 1951). According to Hunt (1961) environmental factors only force accommodative modifications in children’s schemata when the circumstances that the children encounter are within the range of complexity of the schemata that they have available in their repertoire. The two types of communicative matches are simultaneous aspects of the communicative process and each creates the conditions for the other. Consequently their effects are interactive rather than additive. For example, Nelson (1973) observed that children’s rate of language development was most rapid when mothers and their children used the same forms of language (i.e., referential or expressive) and the mothers approved of the children’s utterances on the basis of semantic rather than linguistic criteria. Where one or the other condition was absent, the children’s rate of development was not exceptional. If both conditions were absent, there was a noticeable decrement in the children’s rate of acquisition, Many aspects of the communicative match appear to be motivated partially by the need of children and social agents to comprehend each other. For

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example, social agents most likely modify their language to facilitate the children’s comprehension of their message rather than to provide the children an appropriate linguistic model. Likewise mothers respond promptly to infants’ crying to determine the nature of their needs, or mothers approve of children’s inappropriate linguistic forms to focus on the intention the children are communicating. In most instances both children and social agents probably rely on extralinguistic cues to facilitate the match. For example, parents probably gauge the complexity of their messages by the children’s apparent attentiveness or responsiveness. Consequently nonverbal cues such as eye contact, smiling, or postural attention may be critical in the establishment and maintenance of the communicative match. B. Communication Deficienciesand Delayed Language Development

Although no attempts have been made to delineate the relative efficiency of the early communication of mentally retarded children, peripheral evidence indicates that their communication systems may be impaired from early infancy. Fisichelli and Karelitz (1963) observed that the crying patterns of brain-damaged children are abnormal. In the first week of life, brain-damaged children are not likely to respond to the first application of a noxious stimulus, and when they do cry, the cries have longer latencies and are not sustained for as long a period as are cries from non-brain-damaged children. Schmidt and Erikson (1973) interviewed parents and found that while babies of average intelligence began smiling prior to 5 months, 16% of the retarded children, most of whom were severely and profoundly retarded, did not begin to smile until after 5 months. Schaffer (197 1) found that mothers of autistic children consistently reported that the signaling ability of their children was severely impaired during the early months of life. This was characterized by an almost complete absence of crying in situations where crying was normally expected. These children never cried when they were hungry or for attention, and their responsiveness to pain and discomfort was impaired. They also avoided eye contact, thus disrupting motherinfant interaction dramatically. Frequently mentally retarded infants are listless and less physically active than nonretarded infants (Carter, 1965). Infants with Down’s syndrome are developmentally delayed in their motor performance as early as 6 months of age (Carr, 1970; Share & French, 1974). As a result of this these children make fewer physical demands on their caretakers and appear less attentive or alert than nonretarded infants. If the communicative match between language learners and their social environment is dependent upon efficient nonverbal communication, then any deficiency in nonverbal communication could result in a developmental delay in language growth. The failure of mentally retarded infants to communicate

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efficiently during the preverbal and early verbal stages could result in one or a combination of three responses from social agents which may impede the language learning process. First, social agents could fail to assess the ability of children to comprehend and not modify the complexity of their language sufficiently. Second, social agents may underestimate the ability of the language learners to comprehend and oversimplify their speech to the children, thus failing to provide the children with a progressive linguistic model. Third, the inability of social agents to either interpret the intention or to elicit an expected response from the children may encourage social agents to limit their communicative interaction with the children. There is little evidence to support any of these potential factors due to a lack of research. Comparative studies of the verbal interaction between mothers and their mentally retarded children and mothers and their nonretarded children have consistently found that mothers use significantly more imperatives and behavior requests when they interact with mentally retarded children (Buium et d.,1974; Marshall, Hegrens, & Goldstein, 1973). While imperatives may be easier for mentally retarded children to comprehend, such linguistic forms do not provide a progressive linguistic model and children may respond to them without processing the syntactic structure. Consequently these studies exemplify the oversimplification of speech. In addition, Kogan, Wimberger, and Bobbitt (1969) found that mothers of mentally retarded children use a higher frequency of questions in which they supply the correct answer than do mothers of nonretarded children. This suggests that mothers of mentally retarded children fail to ask questions which are within the children’s range of comprehension and thus exceed their linguistic capabilities. C. Implications for Language Intervention

Delayed speech development among mentally retarded persons is often conceptualized as resulting primarily from a failure of children’s cognitive or linguistic functions or from the failure of social agents to respond appropriately to the children. As a result, language intervention programs are commonly designed by selecting theories which account for the development of these deviant functions, and then translating these theories into instructional programs. The types of theories which have been adapted range from behavioral theories (most commonly operant theories) of language learning, to psycholinguistic theories of the development of syntax and semantics, to cognitive theories of the prerequisites to language development. In addition, many programs are based upon a combination of behavioral and psycholinguistic theories (e.g., Bricker, 1972; Gray & Ryan, 1973; Miller & Yoder, 1972,1974; Stremel, 1972; Stremel & Waryas, 1973) or behavioral and cognitive-linguistic theories (Bricker & Bricker, 1974), using the cognitive and linguistic theories as indi-

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cators of the content and sequence for language programming and the behavioral theories as operational guidelines for language training procedures (Lynch & Bricker, 1972). The recent improvements in language intervention programs have been significant both with regard to their conceptualization of language development and the design of intervention techniques (cf. McLean, Yoder, & Schiefelbusch, 1972; Schiefelbusch & Lloyd, 1974). In spite of these advances, one major problem which persists is the failure of children to generalize linguistic responses which are learned in the intervention setting to their spontaneous speech (Garcia & DeHaven, 1974; Guess, Sailor, & Baer, 1974; Harris, 1975; Miller & Yoder, 1974; Snyder, Lovitt, & Smith, 1975). W e children are capable of learning linguistic responses, they often fail to use this language to communicate. This failure could be attributed to one or a combination of several factors: (1) an inherent inability of these children to use language; (2) inappropriate intervention tactics resulting from an inaccurate translation of theories (Guess et ol., 1974; Miller & Yoder, 1974); or (3) inaccurate theories on which the intervention programs are designed. It is our feeling that the failure to obtain generalization of learned linguistic responses may’ be attributed largely to a neglect of the importance of the social agent. For example, the processes suggested in operant theory as critical to language acquisition are elicited imitation and reinforcement. These processes are not used as widely in the natural course of language development as operant theory suggests, and the applied uses of elicited imitation and reinforcement contradict the concept of communicative match. That is, in the applied setting these processes are used to induce children to conform to the language models seldom allowing language models to conform to children’s level of communicative competence. #en a model says: “Bobby, this is a dog. Say dog,” the model may fail to take into account that the child may already have a functional, though idiosyncratic, word for the referent, or that the child may not be motivated to communicate about the picture of a dog at that particular time. Furthermore, for language models to reinforce only the production of an appropriate response or an approximation of that response informs the children that the most important aspect of the interaction with language models is to conform to their linguistic demands. Because the models do not introduce the response within the context of a real communicative exchange, the children may fail to learn that appropriate linguistic responses will increase their communication efficiency. An even more serious problem is that language intervention programs generally disregard the development of communication. This disregard may be manifested by the procedure of a therapist working with a child in an isolated room for a 15- to 20-minute session 5 times a week. Nowhere in this procedure is there any concern for the communicative competence of the child. First, the

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child is placed in an unfamiliar environment. Since in the earliest stages, children most frequently communicate about their own environment, to develop communication intervention should also occur in their environment. Second, the limited time that therapists spend with children decreases the likelihood that they are sensitive to the children’s habitual response modes or idiosyncratic uses of language. In the normal course of language development effective social agents deal with the idiosyncratic characteristics of children’s communicative repertoire. Third, the employment of brief, daily language training is based on the assumption that language learning will be most efficient when the children are forced to attend to the task in an intensive session. This assumption seems unwarranted since studies which used expansion in daily language training sessions were either unsuccessful (Cazden, 1965) or only marginally significant (K. E. Nelson et al., 1973) in increasing the rate of syntactic development. On the other hand, the rate of expansion in the natural setting is correlated positively with early indices of language development (K. Nelson, 1973; Seitz & Stewart, 1975), suggesting that the effectiveness of expansion is partially dependent on contextual factors. Fourth, while language therapists often inform parents and teachers about the procedures used for language training, there is no guarantee that these procedures are maintained consistently throughout children’s daily activities. Many of these problems have been remedied in some language programs by employing language training procedures in a classroom or daycare center, and relating the programs more directly to the children’s own environment and activities. The lack of concern for children’s communicative competence still remains a problem, however. Language programs have assumed the role of the primary language model for language-delayed children. They presume that since parents and families have been ineffective, more qualified personnel can best replace the family as the primary language models. In doing this language programs have failed to understand the role of the social agent and yet often instruct parents to incorporate the intervention procedures into home settings which are frequently unsuited for such procedures. In general, most language intervention programs have been developed from the principles of language conditioning, and have extended only occasionally into the home by instructing parents to be conditioners. The possibility that learning language may involve more than learning linguistic responses has been seriously neglected. D. Toward a Communication Model

Intervention programs which are developed on the principle that language evolves from the social interaction and nonverbal communication system which exists between language-learning children and their primary language models

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would differ from current language programs in two principal ways. First, the focus of language intervention would be the social interaction between the language learner and the language model. Language intervention programs would be developed in children’s own social environment and would focus on the communication system between the children and their primary language models. The basic strategy would involve training the models to synchronize their communication strategies with those of the children so that there would be a relatively efficient preverbal or nonverbal communication system between them. Once the models had established efficient communication with the children, then the role of the models would be to stress this communication network by gradually enriching and developing the children’s preverbal system into a linguistic system. Three major components would comprise a communication-based language intervention program: interpersonal structure, linguistic structure, and adaptive consequences. While the latter two elements are similar in many regards to those elements which are emphasized in most current language intervention programs, there would be some significant differences in the manner in which these aspects of language would be developed. In the communication-based program, linguistic structure and the consequent events of language would be regulated by the constraints of the interpersonal communication structure. Second, since a communication-based language intervention program emphasizes the role which social agents play in the development of language, there would be an increased attempt to develop language programs around children’s existing primary social agents. In most cases this would involve utilizing family members, most especially parents, as the primary language models. The role of the speech therapist would be to serve as a consultant to the family and to monitor their interactions with the child, and to provide supplementary activities for the child. The speech therapist would not attempt to replace the family as the primary language model, but rather would attempt to demonstrate to the family how their continual patterns of interaction with the child influence the child’s growth and development of language and communication. As the child develops beyond the basic stages of language acquisition and begins to use language to communicate relatively efficiently, language programs may begin to assume a more direct role in the child’s language development and work on developing some of the more complex linguistic patterns. There is some evidence that the approach of using parents as primary language trainers is a relatively effective language intervention technique. MacDonald, Blott, Gordon, Spiegel, and Hartmann (1974) trained parents of 3- to 5-year-old Down syndrome children to act as language therapists in their homes. Only the parents worked with their children after an initial 7-week parent training period. Over a 3-month period the rate of language development of these children was significantly greater than the rate of language development of a control group whose parents had received no training. Seitz and Hoekenga

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(1974) had mothers of mentally retarded children observe and criticize videotapes of their own interactions with their children as well as observe trained speech therapists interacting with their children for several sessions. After the parents received this counseling the children’s rate of language development increased signifhntly even though the children received no subsequent formal language training. What is now needed is continued research concerning the social processes associated with language and a concerted effort to determine how social processes may interfere with the language development of mentally retarded persons. More importantly, current conceptions of the role of the social agent in language intervention need to be broadened, and techniques for increasing the efficiency of the interaction between mentally retarded children and their social agents must be designed, We must remind ourselves that social processes may be as crucial to the development of language as are cognitive and linguistic factors. REFERENCES

Ainsworth, M. Infancy in Uganda: Infant care and the growth of love. Baltimore: Johns Hopkins University Press, 1967. Ambrose, J. A. The smihg and facial responses in early human infancy: An experimental and theoretical study of their course and significance. Unpublished doctoral dissertation, University of London, 1960. Ambrose, J. A. The development of the smiling response in early infancy. In B. M. Foss (Ed.), Determinants ofinfant behmior. Vo1. 1. London: Methuen, 1961. Baer, D. M., & Guess, D. Receptive training of adjectival inflections in mental retardates. Journal of Applied Behavior Analysis, 1971,4, 129-139. Baer, D. M., & Guess, D. Teaching productive noun suffixes to severely retarded children. American Journal of Mental Deficiency, 1973,71,498-505. Baldwin, C . P., & Baldwin, A. L. Cognitive content of mother-child interaction. Unpublished manuscript, Cornell University, 1973. Bateson, M. C. The interpersonal context of infant vocalization. Quarterly Progress Report, Research Laboratory of Electronics, Massachusetts Institute of Technology, No. 100, 170-176, January 15,1971. Beckwith, L. Relationships between infant’s social behavior and their mother’s behavior. Child Development, 1972,43, 397411. Bell, S. M., & Ainsworth, M. D. Infant crying and maternal responsiveness. Child Develop ment, 1972.43,1171-1190. Benedict, H. The role of repetition in early language comprehension. Paper presented at the biennial meeting of the Society for Research in Child Development, Denver, March 1975. BerkoGleason, J. Code switching in children’s language. In T. E. Moore (Ed.), Cognitive development and the acquisition of language. New York: Academic Press, 1973. Bever, T. G. The cognitive basis for linguistic structures. In J. R. Hayes (Ed.), Cognition and the development of language. New York: Wiley, 1970. Bloom, L. M. Language development: Form and function in emerging grammars. Cambridge, Mass.: MIT Press. 1970. Bloom, L. M. One word at a time: The use of single word utterances before syntax. The Hague: Mouton, 1973.

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Guess, D., Sailor, U., & Baer, D. M. To teach language to retarded children. In R. Schiefelbusch & L. L. Lloyd (Eds.), Language perspectives: Acquisition, retardation, and intervention. Baltimore: University Park Press, 1974. Harris, S. L. Teaching language to nonverbal children-with emphasis on problems of generalization. Psychological Bulletin, 1975,82,565-580. Hunt, J. McV. Intelligence and experience. New York: Ronald Press, 1961. Jaffe, J., Stern, P. N., & Peery, J. C. “Conversational” coupling of gaze behavior in prelinguistic human development. Journal o f Psycholinguistic Research, 1973, 2, 321-329. Jenkins, J. Remember that old theory of memory? Well, forget it! American Psychologist, 1974,29,785-795. Kagan, J. On the need for relativism. American Psychologist, 1967,22,131-142. Kobashigawa, B. Repetitions in a mother’s speech to her child. In Working Paper No. 14, The structure of linguistic input to children. Language Behavior Research Laboratory, University of California at Berkeley, 1969. Kogan, K. L., Wimberger, H. C., & Bobbitt, R. A. Analysis of mother-child interaction in young mental retardates. Child Development, 1969,40,799. Kreutzer, M. A., & Charlesworth. W. R. Infants’ reaction to different expressions of emotions. Paper presented at biennial meeting of the Society for Research in Child Development, Philadelphia, March 1973. Lee, L. L. Linguistic approaches to developmental language disorders. Folia Phoniatrica, 1974,26,33-67. knneberg, E. Biological foundations of language. New York: Wiley, 1967. Lewis, M., & Freedle, R. Mother-infant dyad: The cradle of meaning. Princeton, N.J.: Educational Testing Service, 1972. Lewis, M. M. Infant speech. London: Routledge & Kegan, 1951. Lord, C. Is talking to baby more than baby talk? A longitudinal study of the modification of linguistic input to young children. Paper presented at the meeting of the Society for Research in Child Development, Denver, March 1975. Lynch, J., & Bricker, W. A. Linguistic theory and operant procedures: Toward an integrated approach to language training for the mentally retarded. Mental Retardation, 1972, 10(2), 12-16. Lynipp, A. W. The use of magnetic devices in the collection and analysis of preverbal utterances of an infant. Genetic Psychology Monographs, 1951,44,221-262. MacDonald, J. D., Blott, J. P., Gordon, K., Spiegel, B., & Hartman, M. An experimental parent-assisted treatment program for preschool language delayed children. Journal of Speech and Hearing Disorders, 1974,39,395-415. MacNamara, J. Cognitive basis of language learning in infants. Psychological Review,, 1972, 77,282-293. Mahoney, G. An ethological approach to delayed language acquisition. American Journal of Mental Deficiency, 1975,80,139-148. Marshal, N. R., Hegrens, J. R., & Goldstein, S. Verbal interactions: Mothers and their retarded children vs. mothers and their non-retarded children. American Journal of Mental Deficiency, 1973,77,415-419. McLean, J. E., Yoder, D. E., & Shiefelbusch, R. L. (Eds.) Language intervention with the retarded. Baltimore: University Park Press, 1972. McNeill, D. The creation of language by children. In J. Lyons Br R. J. Wales (Eds.), Psycholinguistics papers. Edinburgh: University of Edinburgh Press, 1966. McNeill, D. The acquisition of language. Cambridge, Mass.: MIT Press,1970. Menyuk, P. Sentences children use. Cambridge, Mass.: MIT Press, 1969.

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Cognitive Theory and Mental Development

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EARL C BUTTERFIELD

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RALPH L SMITH CENTER FOR RESEARCH IN MENTAL RETARDATION UNIVERSITY OF KANSAS MEDICAL CENTER. KANSAS CITY. KANSAS

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DONALD J DICKERSON UNIVERSITY OF CONNECTICUT. STORRS. CONNECTICUT

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I . Introduction I1. Recent Developments in Experimental Psychology A . Present Status of Cognitive Psychology B How Cognitive Psychology is Changing 111 Explanation by Complete Specitication of Unobservables A Extrapolation of Basic Principles B Flow Charts and Computer Programs C Logical Positivism and Operationism D. ConvergentValidation E The Search for Additional Validation Tactics N . Individual Difference Tests A . S i s that Predict Their Use B Making the Tests: An Encouraging Example C. Meaning of Covariance Tests D. How Individual Differences Tests Can Validate Cognitive Theory E Making the Tests: An Instructive Example F. Probability of Widespread Use V. Cognitive Instruction A Pressures for Its Use B Methodological Requirements C Two Instructional Experiments D Unanswered Questions of Use VI Postscript References

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Psychologists who claim mental retardation as a research specialty draw heavily on developments in general experimental psychology. This can be seen in their experimental methods and in their theorizing. For instance, psychological theory developed from the study of animals and normal adults has been applied often to mentally retarded people. Ellis (1963) borrowed from the animal laboratory the notion of stimulus trace which he developed into a particularly heuristic organization of the literature on mentally retarded people’s memory functioning. Several years later, he modified notions of primary and secondary memory, developed by researchers who studied normal adults, to reorganize what was then known about mentally retarded people’s memory functioning (Ellis, 1970). Similarly, Spitz (1963) applied Gestalt theory, and Zeaman and House (1963) applied attention theory to other aspects of the behavior of mentally retarded people. Prior to these applications, Gestalt and attention theory were both based more on research with animals and normal adults than on work with the mentally retarded. There are different ways to interpret the extensive borrowing by retardation specialists from their colleagues who study animals and normal people. It could reflect an essential similarity between intellectually deviant and average people. Or it could be that scientists specialize according to their theoretical or disciplinary connections rather than according to characteristics of people they study. Whatever the explanation, the psychology of mental retardation clearly depends importantly upon theory and technique of general experimental psychology, which has changed greatly in the last 30 years (Segal8c Lachman, 1972; Weimer, 1974). Those changes have been reflected in the psychological study of mental retardation, and there is considerable room for debate over how well this has served our specialty. But the pattern is well established, so it seems appropriate to examine the discipline from which we draw so heavily. The first purpose of this chapter is to characterize some of the changes in experimental psychology since 1950. Starting there allows us to paint a broad picture of the backdrop for the present state of affairs, which we characterize as labile and unsatisfying. We characterize contemporary experimental psychology, which is perhaps better called cognitive psychology, as having a poor match between its conception of scientific explanation and its methods for testing theory, The second and main purpose of this paper is to illustrate two methods which hold some promise of meeting the implicit requirements of cognitive psychology’s conception of scientific explanation. We endorse the suggestion of others that cognitive theory is dangerously close to losing its ties to laboratory data (cf. Postman, 1975; Underwood, 1975), and we propose that techniques of cognitive instruction and tests for individual differences can provide needed empirical validation for cognitive theory. Our illustrations of these methods are

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experiments conducted with mentally retarded people and children. There are hardly any examples of these methods in the literature on normal adults. The chapter’s closing section tries to explain why methods which seem promising for general experimental psychology are being refined first by specialists in retardation and childhood, the investigation of which we think go hand in hand.

II. RECENT DEVELOPMENTS IN EXPERIMENTAL PSYCHOLOGY

Battig (1975) observed that “the recent ascent of cognitive psychology to its present exalted status undoubtedly constitutes one of the most sudden and remarkable turnabouts in the entire history of a discipline . .. .” There are many signs that he is correct: Experimental psychology has turned to mentalism with remarkable suddenness (cf. Chase, 1973; Estes, 1975; Restle, Shiffrin, Castlellan, Lindman, & Rsoni, 1975; Segal & Lachman, 1972; Solso, 1973, 1974, 1975; Weimer & Palemo, 1974). Some see this as a revolution (cf. Weimer, 1974); others see it as a minor evolution (cf. Battig, 1975). To us, cognitive psychology seems an outgrowth, however large, of identifiable historic forces that might best be traced after seeing where the discipline now stands. Our discussion of cognitive psychology’s present status and evolutionary history is based largely on the more thorough account of Lachman, Butterfield, Dooling, and MistlerLachman (in press). A. Present Status of Cognitive Psychology

Cognitive psychology’s subject matter is people’s mental states and processes. To expose these it uses laboratory methods developed for the study of attention, memory, language, and perception, and especially the techniques of verbal learning experimentation. Its goal is to create generalized or nomothetic theory of human cognition. Its preferred form of theory is a complete specification, as in flow charts or computer programs, of the mental states and processes which occur between informational input and behavioral output. Because its subject matter is largely covert, it sees a need to rely heavily upon convergent validation. The notion is that a confident inference about any mental state or process requires supportive evidence from at least two operationally distinct measurement procedures. Without such convergence, theory might concern little more than procedurally idiosyncratic events. Partly because it has been difficult to achieve convergence, and partly because of the recognition that people tailor their thinking to the differing demands of their environments, cognitive psychologists are giving increased attention to detailed task analyses which, like their theories, they express in flow charts.

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Attaining convergence seems to require reasonably complete understanding of the processing requirements of the tasks used. Definitive task analyses are also necessary to evaluate failures to attain convergence, which are distressingly frequent. Task analysis can help separate theoretically important from theoretically unimportant failures of convergence. Divergent data are important when they show that people lack the cognitive characteristic the different tasks are intended to jointly reveal. They are unimportant when processes peculiar to the different experimental operations mask the existence of the sought-for cognitive characteristic. Notice that task analysis and the theoretical particularism that it seems to imply are not ends in themselves. Task analysis is a necessary means toward the goal of nomothetic cognitive theory. But cognitive psychologists often call their task analyses “models,” or they express them in flow charts and computer programs. These practices make task analyses look like theories (e.g., Atkinson & Shiffrin, 1969) instead of like more restricted understandings, which are mere steps along the way to attaining general theory. B. How Cognitive Psychology is Changing

Cognitive psychology is a changing approach to human experimentation. Its stable features may yet prove to include little more than commitment to explaining human cognition, efforts to secure converging validation for mentalistic concepts, and a procedural reliance upon detailed task analysis. But two of the directions it is going seem likely to produce stronger bases for cognitive theory. We refer first to a dramatically increased concern for individual differences in the way people think.Because some of their methods have been finely honed to the purpose of exposing mental activities, experimental psychologists are increasingly often exposing the fact that people think in diverse ways, even when informational input and environmental arrangements are tightly controlled (Battig, 1975; Reitman, 1969; Simon, 1975). The existence of reasonably complete analyses of verbal learning tasks, and the measurement procedures necessary to the construction of those analyses, have already exposed the multiplicity of cognitive tactics which people have at their command and the flexibility with which they diversely deploy them to solve particular cognitive problems (e.g., Butterfield & Belmont, 1972, in press; Butterfield, Wambold, & Belmont, 1973). It seems that cognitive psychology is focusing ever more directly on individual differences in how people think. This focus includes not only differences between people (Underwood, 1975), but differences within people as well (Battig, 1975). It entails direct analyses of individual people’s changes in cognitive strategy that result from increasing experience and from changing environmental arrangements (Butterfield & Belmont, in press), as well asdirect analyses of how people differ cognitively from one another (Hunt,

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Frost, & Lunneborg, 1973). The second movement is toward cognitive instruction, and it is illustrated in several experiments by Craik and Tulving (1975). The trends toward studying individual differences and toward using cognitive instruction seem likely to last because they are consistent with changes that have paralleled psychology’s turn to the study of cognition. To see this, we must trace back only one of the many threads in the tapestry of modern mental science: its conception of scientific explanation.

111. EXPLANATION BY COMPLETE SPECIFICATION OF UNOBSERVABLES

A. Extrapolation of Basic Principles

We approach the new mentalism’s conception of scientific explanation by starting with neobehaviorism, which took nomothetic explanation as its goal and laboratory experimentation as its method of proof. In these respects, cognitive psychology is exactly like neobehaviorism. But neobehaviorism also tried to build its theories of human behavior from a very mall set of basic principles, which were developed mainly from experimentation with animals. Its commitment to using few principles and to deriving them from animal experimentation left behaviorism with extrapolation as its main means of accounting for human behavior. Thus, while Dollard and Miller’s (1950) basic principles were firmly grounded in laboratory data, their extrapolations to human personality were only theoretically guided, as was Skinner’s (1957) extrapolation of operant principles to speech and language. Psychology moved away from extrapolation. Two of the reasons are noteworthy. When World War I1 overtook America, psychologists were put to work on problems created by mixing men with war machines. For example, they were asked why pilots so often crashed when landing plane X? And why do radar operators sometimes not see whole squadrons of enemy planes on their screens? Questions like these were not addressed well by extrapolation. Instead, psychologists had to analyze directly the performance demands of particular war machines. They found that changing either the machine or its operator changed the performance of what came to be called the manlmachine system. In some systems, performance was best improved by working on the men; in others, on the machines. Intensive task analysis was required to determine which approach would be most effective. Among the important features of these analyses were the directness of their focus on human performance and the completeness with which they sought to understand it. These features later characterized psychologists’ analyses of verbal learning tasks, which became important tools for the study of cogmtion.

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Another notable reason to seek alternatives to explanation by extrapolation came when psychologists tried to account for speech and language with associative learning principles borrowed from the animal laboratory. Linguists scrutinized this effort closely, and with forceful arguments convinced their psychologist antagonists that language was complexly governed by peculiarly human rule systems, which the linguists called competence. Psychologists concluded that to account for language they would have to focus directly on it, and that they would need to posit and empirically document the role of internal mechanisms. The occasion for a changed style of scientific explanation was thus established. Arguments by linguists and the exigencies of war dictated that the new style would be to explain peculiarly human performance by positing internal mechanisms, like rule systems, which could be satisfactorily revealed with the help of detailed task analyses. It remained to give precise form to the new style, and computer science helped do that. B. Flow Charts and Computer Programs

It would be hard to overestimate the contribution of computer science to psychology. It gave powerful computational tools and simulation techniques, and by spawning artificial intelligence, it stimulated psychologists to apply these tools to complex and creative human behavior. It gave cognitive psychology its most important analogy to man-the computer itself. What a rich lode of concepts that turned out to be! But the most important contribution of computer science was explanation by compZete specification of underZying states and mechanisms, as in computer programs and flow charts. In large measure because of its contact with computer science, cognitive psychology is trying now to construct a generalized program for human information processing. Whether it will succeed is surely debatable, but that is the goal. Consider its requirements. C. Logical Positivism and Operationism

Compare the tactical consequences of seeking explanation by complete specification of mechanism versus seeking explanation by extrapolation of basic principles. When neobehaviorists wished to establish the scientific validity of theory as it applied in the animal laboratory, they were logical positivists and operationalists. Logical positivists hold that scientific statements may be of two kinds: logical or mathematical relations that derive their validity from rules for their manipulation; and factual propositions that can be verified by observation. They also hold h a t scientific statements can be translated into the language of physical things. According to operationism, the meanings of scientific concepts are the experimental operations performed when studying them. Between them, logical positivism and operationism preclude mentalistic explanations. They

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leave the psychological scientist with physically defined concepts having to do with stimuli impinging upon the organism or with its responses. Tactically, they leave him with establishing empirical relationships or functions between concepts that are tied down to physically describable things on both the stimulus side and the response side of the organism. While such functions could be fairly characterized as capturing the internal workings of neobehaviorists’ laboratory animals, they carried little mentalistic flavor and, in spirit depended upon minimal conceptualization of the internal workings of their subjects. The main focus of neobehaviorism was thus on the external world, and theory was judged largely by its scope and its ability to predict experimental data. D. Convergent Validation

Verifying empirical relationships between operationally defined events is not sufficient validation of theory that focuses on inner workings. So cognitive psychologists have sought additional tactics. Lachman ef ul. (in press) have likened the main alternative so far developed to the tactics of an industrial spy: “Sitting on a hillside above a factory with field glasses he watched railroad cars arrive with raw materials. They are taken into one end of the factory, while at the other end trucks pick up completed products. The spy’s job is to figure out what transpires in the factory. Every once in a while he can send in a car of materials which he has selected, and later he can see what comes out, but he cannot take a trip through the factory. We are in a similar position with respect to human cognition. We cannot observe it directly.” Cognitive psychologists have tried to solve the problem of unobservability much like physical scientists whose subject matter is also unobservable. The temperature of the sun, for example, cannot be measured directly, but values have been assigned to it by attending to observable phenomena which limit its possible temperature. Psychologists use this same method of making observations which place constraints upon the possible workings of the cognitive system. Unobservable properties of the system give rise to observable phenomena, from whose measurement interlocking inferences are made. When vmious measurements confirm an interlocking inference, it is taken as a valid, factual statement about some unobservable property of the system. This technique is called convergent validation; when data of several different kinds converge upon a conclusion it is validated. In view of the goal of cognitive psychology, and despite the evident success of the method in the physical sciences, convergent validation seems unlikely to be the final answer to the problems created by focusing theory on mental events. Convergent validation is too similar to what psychologists used to call construct validation for many of them to see great new hope in it. Moreover, as it has been applied so far, it has addressed the validity of particular processes, like iconic

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memory, rather than the validity of complete specifications of the larger cognitive system. And it has yet to be applied even to all component processes postulated in cognitive theory. For example, several contemporary models of memory either explicitly posit or directly imply a modern-day homunculus, called the executive function by Greeno and Bjork (1973), but so far only one experimental operation has been devised to reflect it (Butterfield & Belmont, in press), and that one is indirect. Such concepts have not been converged upon in the laboratory, yet they continue to appear in mentalistic theories. E. The Search for Additional Validation Tactics

The search for needed new tactics to validate cognitive theory has led psychologists distressingly far from their laboratories. Some are citing physiological findings as support for their theories. For example, Atkinson and Shiffrin (1969) have partly justified the notion of a short-term memory store by citing Milner’s (1967) evidence that surgically produced bilateral hippocampal lesions produce marked postoperative deficits in long-term but not short-term recall. Even discounting its interpretative problems, physiological evidence is not very helpful; most cognitive concepts find no support yet in anatomical or physiological data. Another tactic, which wanders even further from the laboratory, is to argue that a particular concept or theory makes evolutionary sense. Thus, Lieberman (1975) seeks support for the motor theory of speech perception in skeletal remains of early men. There is probably a place in cognitive science for tactics such as adducing physiological evidence and arguing evolutionary sensibility. But their use cannot do away with the need for additional laboratory tactics. In this regard, we note that there is a theme in these tactics that could guide the development of laboratory methods. The theme is that cognitive theory should reflect all that we know about thought. If there is evidence that neurologic damage selectively attacks a particular mental function it seems reasonable for cognitive theory to separate that function from others, because we know that cognitive capacities are based in the brain. If there is reasonable evidence of selection pressures that should have resulted in particular cognitive adaptations, it seems valid to specify these in theory, because we know that man evolved and that must mean that his cognition evolved too. We see two laboratory tactics for validating cognitive theory that would be honest to this theme. The first is an individual differences test advocated by Underwood (1975). It is a close variant of the procedures of convergent validation, and it captures the knowledge about thinking that people do it differently. The second is to use experimental procedures to elicit or inhibit thinking by direct instruction. It reflects the theme by building on the fact that cognition is changed by experience. By our view, these two tactics hold the

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greatest present promise of making cognitive theory more meaningful. We do not imagine that by themselves they will allow a complete specification of the human intellect. But cognitive psychology has inherited the laboratory traditions of neobehaviorism and verbal learning. Therefore, it seems likely that it will try to evolve laboratory tactics suitable to its mentalistic purpose. Since individual difference tests seem consistent with the theme of cognitive psychology’s extralaboratory alternatives to specifying empirical functions, let us see what they might amount to. IV. INDIVIDUAL DIFFERENCE TESTS

Underwood (1975) proposed that cognitive theory be formulated in ways that allow individual difference tests. He viewed this proposal as an antidote for the proliferation of mentalistic models. Our guess is that many of the models he was concerned about are not general enough to be called theories; rather, they are task analyses necessary to the ultimate construction of theory. Still, the need for his antidote is manifest. A. Signs that Predict Their Use

The case for attending to cognitive differences between people has been made in many ways recently. Simon (1975) used II priori analysis to show that even simple problems can be solved with several solution strategies and that “different strategies have different degrees of transferability, place different burdens on short-term memory and perception, and require different learning processes for their acquisition.” Reitman (1 969) analyzed introspective protocols from participants in standard laboratory experiments to show that they reflect a far greater variety of mental methods that our usual dependent measures reveal. He argued from his observations that our science must fall short of its goal until this variability is controlled. We would add, it should be measured directly, manipulated and given theoretical status. The idea that subjects’ methods must be known has been translated by Newell (1973, pp. 294-295) into two mandates: “Know the method your subject is using to perform the experimental task,” and “Never average across methods.” Anders (1971) classified his subjects according to their reports about how they had studied lists during input, and as a consequence achieved a marked increase in the regularity of latency data reflecting memory searches. Hunt et d. (1973) showed that psychometric intelligence predicted individual differences in a large variety of laboratory tasks. Battig (1975) made the case even more directly, and he extended it to within-individual differences. He examined data from the most thoroughly analyzed experimental procedures so far produced by psychologists: serial learn-

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ing, pairedassociates learning, verbal discrimination learning, and free recall. By capitalizing on the accumulated understanding of processes underlying performance in these tasks, he was able to show not only that different people use different processes on the same task, but that each individual uses different processes on different trials and even on different items within single trials. Battig (1975, p. 225), was “able to identify no task or conditions whatever where the typical individual subject will use only one type of processing consistently for different items of a particular type either within or across [within-individual differences] .. .whether we successive trials. We find assess them at the time the individual is actually studying the materials, immediately after they have been responded to correctly, or through some type of post-experimental inquiry.” His conclusion is that “. . .no matter where or how it is evaluated, any theory or model may well be both entirely correct or totally wrong, depending upon what type(s) of processing the particular subject happens to be using for a given item within a particular task.” To be valid, theories must account for the multiple processes which people use in their cognitive endeavors. In aggregate, the foregoing arguments speak persuasively for the use of individual difference tests. On the other hand, there are counteracting forces, principal among which is psychology’s intent to produce nomothetic theory. Underwood (1975) argued that the pervasiveness of individual differences demanded that they be reflected in the processes postulated by nomothetic theory, but he did not propose making theories idiographic. Nomothetic theory has been the goal of scientific psychology since its birth, and even the new mentalists would interpret the introduction of idiographic elements into theory as inconsistent with their nomothetic purpose. Still, as we have tried to show, there are strong pressures for an alternative to the strict nomothetic approach. Psychologists have been able to make mental events the focus of theory because their analyses of the cognitive requirements of many laboratory tasks are fairly complete. The experimental controls and dependent measures used in these analyses are being continuously refined, leaving individual differences as a chief source of variability in laboratory data. Studying mental events highlights the need for converging operations, but convergence is often difficult to obtain. The strategy of seeking convergence is thus stretched, and cognitive scientists are evolving a formula to guide their search for alternatives. The formula seems to be that their theories should be true to all that we know about thought. Among the things that we know for certain are that people think differently from one situation to another and they differ from one another in how they think. These considerations suggest that cognitive psychologists should focus more on individual differences. It seems to us that the question is not whether experimental psychology will introduce idiographic elements into theory. Rather, the question is how it will

.. .

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ground those elements in data. What will its methods be for exposing theoreticaUy important individual differences? As in all matters of prognostication, the answer to this question is not entirely certain. But the general outlines of an acceptable method seem to be shaping up in laboratories focused on mental development and mental retardation (cf. Belmont & Butterfield, in press). Interestingly enough, while the methods are coming from students of the mentally retarded and of children, the most comprehensive statement of the methodological requirements of theoretically supportive individual differences tests has come from Underwood (1975), whose main studies have been with normal adults. According to Underwood (1975), we first need an experimental observation important enough to merit theoretical explanation. Next, we need that explanation. Finally, we need at least two independent measures of the process which the theory says accounts for the observation. Underwood’s test is to administer both measures to each of many people, and to correlate the resulting scores. If the scores covary, the investigator may conclude that his theoretical process is important. Thus, the test is to see whether two independent measures of a theoretical process converge on the conclusion that the process vanes systematically across people. B. Making the Tests: An Encouraging Example

To illustrate the individual difference test, we will describe a study done by Ashby (1976), who started with the observation that the information processing of children undergoes a fundamental change during the age range 5-7 years. This is when children first show evidence of such activities as covert rehearsing in order to remember (Conrad, 1971; Flavell, 1970), testing hypotheses as they solve discrimination problems (Gholson, Levine, & Phillips, 1972), and organizing items by categories in free recall (Kobasigawa, 1974). As his theoretical interpretation of these changes, Ashby took the hypothesis that children begin to combine cognitive tactics into effective information processing routines as they reach middle childhood. At about this age, they begin to construct strategies or plans appropriate to specific tasks. The use of such strategies entails the planful coordination of component activities. Ashby’s research focused on individual differences in the coordination of component cognitive activities. He administered two tasks to kindergarten and first-grade children, both of which required the coordination of separate activities. He hypothesized that if the deliberate combining of separate activities developed during middle childhood, then children’s success on the two tasks should covary: they should either pass both or fail both. This is exactly the sort of individual difference prediction that concerned Underwood. Ashby used two tasks which require substantially different component skills for their solution. He used pretesting and teaching to guarantee that children

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possessed the requisite component skills. Then he administered experimental tests to see whether the children combined the components. One test was developed by Kendler and Kendler (1967), and it is called the inferential behavior task. The other was a type of serial memory task, called sequence counting. The individual difference question was whether the children who combined planfully in the inferential behavior task were the only ones to combine in the sequence counting task, and vice versa. For the inferential behavior task, Ashby first presented children with two color-coded plungers. He taught each child to pull one of the plungers to obtain a large marble and the other to obtain a small marble. Then, in a separate part of the training, he taught each child that putting a large marble in a hole produced gum, but inserting a small marble produced nothing. To test for inference, he asked the child to get the gum by himself, that is, without being given a marble by the experimenter. To solve the problem, the child needed to combine two separately learned activities; pulling the appropriate plunger to obtain a large marble, and then using the marble to obtain gum. Ashby gave each child 2 minutes to combine these behaviors. Ashby classified each child as having passed or failed the inferential behavior task by considering whether he obtained gum, and if he did, how long it took him. The purpose of his scoring system was to determine whether the child combined plunger pulling and marble inserting as a consequence of forming a deliberate plan to obtain the gum, or by trial and error. Depending upon how a child behaved, he was first scored as having attained a direct solution, an indirect solution, or no solution. A direct solution amounted to getting the gum without an irrelevant response, i.e., by pulling the appropriate plunger, taking the large marble, and inserting it in the hole. An indirect solution was scored for getting the gum after an irrelevant response, i.e., by pulling both the plungers before putting the big marble in the hole. No solution was not getting the gum in 2 minutes. Seventy-five children participated in the experiment: 37 achieved direct solutions; 22 indirect; and 16 no solution. All of the no-solution children were said to have failed the task, since not getting the gum seems a fair indication of not planning to combine the component activities. But the direct and indirect categories are ambiguous. A child who did not invent a solution plan in advance might nevertheless pull the lever which gave him a big marble, and upon seeing it, he might put the marble in the hole. This amounts to happy chance, not a planful solution. Similarly, a child might form a plan, but forget which lever yielded the big marble. Half the time, this would lead to an indirect, but nevertheless planful solution. Ashby used response time to resolve the ambiguity about whether a solution was planful or resulted from trial and error. He measured how long it took from the child’s first plunger pull until he put the large marble in the hole. He reasoned that a child whose solution was guided by a plan would combine his responses quickly, whereas

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solution by trial and error would yield a slower response sequence. He found bimodal distributions of these times, with the break in the distribution coming at about 8 seconds for children with direct solutions and at 16 seconds for those with indirect solutions. Children who took longer than these times were considered to have failed the test. There were 9 (out of 37) of these in the direct solution category and 15 (out of 22) in the indirect category. Adding these to the 16 no solution children gave a total of 40 classed as failing the inferential task and 35 classed as passing. Successful sequence counting also required the child to combine two component activities. Ashby assessed counting with a simple pretest. The second component was serial recall of a list of pictures, and Ashby taught it. He gave the child a deck of cards picturing eight common objects, and he showed the child a panel depicting a particular order of these pictures. Training consisted first of a series of trials during which the child could use the picture sequence on the panel to fill in an incomplete sequence specified by the experimenter. The experimenter would place two of the pictures on the table, separated by space enough for six of the child’s cards. His task was to select from his deck the cards which intervened on the panel between the two experimenter-placed cards, and then arrange the cards between the experimenter’s, according to the order on the panel. For example, with a panel arranged in the order moon, car, boot, tree, truck, star, hat, and flower, the experimenter might place the picture of a car to the child’s left and hat to his right. The child should then arrange the boot, tree, truck, and star in that order between the car and hat. Although the experimenter always allowed space for six pictures, a particular trial might call for the child to place any number from 1 to 6. During the second phase of training, the reference panel was covered during each trial, but exposed afterward for feedback. Gradually, the child learned to reproduce the sequence, or any portion of it, from memory. During the test for sequence counting, the reference panel was removed. The experimenter put out two cards, as before, and said, “Remember, some pictures go between these two. What 1 want you to do this time is tell me how many pictures go between the two pictures that I will show you each time. If you have remembered everything that you have learned so far, you should be able to figure out the number of pictures that go between the two pictures on the cardboard.” The subjects were given three blocks of six test trials, on each of which they were required to say how many (1 to 6) pictures went between the two shown. The child was told “Right” after each correct response. When wrong, he was told, “No, that’s wrong; the correct number is The instructions were repeated every six test trials. To solve the sequence counting test, the child must combine serial recall and counting. He must recall the intervening items from memory, and then count them. Ashby credited the child with planful combination of the two operations

.”

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if he gave five correct responses in any of the three blocks of six trials. By this criterion, 30 children passed and 45 failed the sequence counting task. To be convincing, an individual difference experiment must be designed so that it can yield cross-task correlations that are not amenable to trivial interpretations, and then it must yield high correlations. Ashby’s experiment succeeded on both counts. It sought evidence for a process that might underlie behavior in a wide variety of situations; namely, planfully combining component cognitive activities. He used two experimental tasks which by rational analysis seem to depend upon combining different component activities. It is important that the combined components were different; in retrospect no one can say that the observed correlations depend upon similarity of components rather than on similarity of process. He guaranteed by pretesting and by training that his subjects could perform each of the called for components. The only question was whether they would combine them, and his criterion measures clearly depended upon that. We will show below that such apparently tight design does not always assure high correlations, but in Ashby’s case it did. Twenty-seven of the 30 children who passed sequence counting also passed the inferential task. Thirty-seven of the 45 who failed sequence counting failed the inferential task. Chi square shows that success on the two tasks covaried significantly (x2 = 37.7, p < .001). The degree of covariance was great: the maximum possible contingency coefficient for a 2 X 2 table is .71; Ashby’s data yielded a coefficient that was 80% of this maximum (C = S7). The correlation between performance on the two tasks was significant for both kindergarten (x2 = 10.4, p < .01) and first grade children (x2 = 2 7 . 0 , ~< .001). Performance on the sequence counting task was significantly related to grade level, though only marginally (x2 = 5.1, p < .05). Inferential behavior was not related to grade level (x2 = 2.3, p > .1). The data on which these statistics are based may be seen in Table I, which also gives expected frequencies based on observed marginal totals of 2 X 2 tables relating task performance at each grade level separately. Notice that the observed frequencies exceed the expected for the concordant groups (Pass/pass and Fail/Fail), while for the discordant groups the expected frequencies exceed the observed. Ashby’s results nicely illustrate what Underwood meant by individual difference tests. They show strong covariation between two independent measures of the process of combining cognitive tactics. They establish the theoretical importance of that process, even though the narrow age range studied precluded strong relationships between age and performance on either of the process measures. We do not doubt that Ashby would have found striking age trends for both sequence counting and inferential behavior if he had studied older children too. But demonstrating those age trends would not have set his findings apart from those of many earlier investigators. The importance of Ashby’s data lies in their demonstration that performance on his two tasks covaries, independently of age.

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TABLE I OBSERVED AND EXPECTED FREQUENCY OF PASSING AND FAILING INFERENTIAL AND SEQUENCE COUNTING TASKS FOR KINDERGARTEN AND FIRST-GRADE CHILDR EN'

Grade

Inferential behavior

Sequence counting

Observed

Kindergarten

Pass Pass

Pass Fail Pass Fail Pass Fail Pass Fail

a

3-18

6 2 21 19 2 1 16

10.22 6.22 16.78 11.05 9.91 8.95 8.05

First grade

Fail Fail Pass

Pass Fail Fail

Expected

'After Ashby (1976).

C. Meaning of Covariance Tests

Here is the nub of the argument: A successful individual difference test simultaneously reveals a process and demonstrates its theoretical importance. The most direct way we have of showing that we are studying an individualdifference process is to show that it is reflected in various tasks. Two tasks are the minimum. Notice, too, that the covariance test cannot use a measure like age. Age is not a process variable, and showing that performance on any task covaries with it fails to show that the task measures any process, let alone one that may interest us as scientists. Finding an age trend merely sets the stage for a developmental psychologist to make an important individual difference test, just as finding a performance correlate of IQ sets the stage for the student of mental retardation. That stage was set for Ashby by the many other investigators who showed that behaviors like the ones he studied change with age. His findings enhance the theoretical importance of their work. They do that first by establishing that there is a process which might develop, rather than a bunch of tasks which are developmentally sensitive for unrelated and unknown reasons. But there is a larger importance to individual difference tests, which is why Underwood advocated their use. Underwood argued that theorizing about internal processes is an inevitable result of studying human beings. But he was also concerned about how rapidly cognitive psychologists are producing so many theories of internal processes. His antidote was to discard every theoretical model that does not pass an individual difference test, and he proposed that such tests should be the first ones for every theory. In this view, no psychological theory merits scientific consideration unless it meets the condition that at least one of its postulated processes can be measured by two independent procedures whose results give reliable covariance .

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across people. It is not enough for our theoretical constructs to be tied tightly to observable behavior. They must be tied to behaviors that reliably distinguish among people by predicting other behaviors. Underwood’s proposal implies that process variability is so fundamentally human that every psychological theory must clearly reflect it. Unless it passes this test, a theory deserves no other. It follows that this larger importance can also flow from individual difference tests: Scientific theories that would clutter our efforts will be discarded, while those that hold promise of clarifying human nature will be subjected to more intensive scrutiny . Ashby’s experiment grew from a theory enunciated by Dickerson and his students (Dickerson, Siladi, Goldfield, & Ashby, 1975). Among other things, the theory specifies how combining cognitive processes should affect behavior in several cognitive domains. Ashby’s experiment gives the go-ahead for further tests of this theory, to which we turn in order to illustrate how this sort of individual difference test relates to the explanatory goal of cognitive psychology. D. How Individual Differences Tests Can Validate Cognitive Theory

Recall that the explanatory goal of cognitive theory is a complete theoretical specification of underlying processes. There is no hard and fast means to this goal, but if a process account is complete, then it should apply to many superficially different tasks and it should hold across apparently diverse subject groups. The role of individual differences tests is to meet these expectations by exposing theory to what can be called the task test and to the person test. Individual differences tests require that at least two measures of the target process be obtained from each person, and these measures must be independent. The independence criterion is necessary to lessen the likelihood that covariance of the measures reflects a process other than the one of interest, and it is met by employing tasks that are dissimilar except in their dependence upon the process of theoretical interest. In other words, the test requires that the theory include a specification of all of the relevant processes for each task employed to test it. The burden is upon the experimenter to perform thorough task analyses and to incorporate into his theory the understandings they produce. The theory must specify both the similarity and dissimilarity of underlying processes required on a large variety of tasks. One test of how well the theory does this is whether all of the tasks which the theory says should reveal covariance across people produce data that are on scale. We call it the task test, and it is failed when any specified task yields data that are on the measurement floor or ceiling. The theoretical problem is to specify tasks that are different with respect to all but one underlying process, and to specify them so precisely that all tasks are in the difficulty range required to keep performance of the experiment’s participants

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fully on the tasks’ measurement scales. Increasing the number of tasks employed decreases the probability that the theory will succeed, so by performing individual differences tests with many tasks, one can stress his theory’s completeness. The requirement of individual difference tests that all tasks be administered to all subjects provides the occasion for the person test. The role played by a theoretically important process varies from time to time, even for the same person performing the same task (Battig, 1975; Kendler & Hynds, 1974). This means that a complete theory must specify the conditions under which people will and will not exhibit the processes relevant to each task it says reflects its important processes. The most direct way to test the completeness of a theory with respect t o such specifications is to perform experiments on groups of subjects who vary widely on variables that are known to relate to cognitive processing. Intellectual level is one such variable and age is another. The person test of cognitive theory thus amounts to performing similar experiments on people who vary widely with respect to variables like age and intelligence. If high covariances are achieved across many tasks even when subject characteristics change substantially, then the investigator can feel greater confidence in the completeness of his theoretical explanation. To give convincing bite to the task and person tests, an individual difference test must yield high covariances. A small correlation, regardless of its statistical reliability, is not convincing evidence that an investigator has completely specified underlying process. Individual difference tests require that the investigator solve his task and person problems experimentally, not by recourse to a strict level of statistical confidence. The point of the individual difference test is to show that a theory can arrange to collect data that reflect a single process, and in the correlational arena, single process means perfect covariance. Low correlations mean either inadequate experimental control or lack of a complete theory. By insisting upon high correlations, we require that the experimenter exercise experimental control during data collection. In this way, we seek to obviate much of the objection to correlational evidence: The intent is to make individual difference tests as interpretable as manipulative experiments. E. Making the Tests: An Instructive Example

This experiment was conducted to stress the theory which says that combining cognitive operations is an important mental process. It employed four tasks rather than two. They were deliberately selected to tap a wide apparent range of behaviors. It studied institutionalized mentally retarded adults. The subjects were deliberately different from Ashby’s in as many ways as was practical. The idea of the experiment was to see whether providing occasions for task and person problems would change the conclusion from Ashby’s experiment that combining cognitive operations is an important mental process.

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We observe in advance that the experiment showed statistically reliable covariance (p < .001) among three of its four tasks. Still, it was not as successful as Ashby’s with respect to affirming the importance of combining cognitive operations. That is why it serves well the purpose of illustrating the peculiar standards of cognitive psychology’s preferred brand of scientific explanation, We administered free recall and memory reorganization tests to the same mentally retarded people to whom we also gave the inferential and sequence counting tasks. Complete data from these four procedures were secured from 40 institutionalized adults, average age 34.2, average IQ 62. The inferential and sequence counting tasks were administered as Ashby did. Here are our other two procedures. 1. FREE RECALL

The free recall task was used to assess the combining of component activities in order to organize information for recall. The procedure was fashioned after Kobasigawa (1974) and Moely, Olson, Halwes, and FlaveU (1969). Four experimental steps were taken: First, we determined that each subject could name and categorize 64 pictures; then we gave a free recall pretest followed by a training procedure; finally, there was a free recall posttest, from which the data of interest came. The materials included eight blue cue cards and 64 white recall cards. Each cue card depicted a place, and the recall cards pictured objects commonly found in those places. For example, one cue card showed a dining table and chairs; its associated recall cards showed a plate, bowl, picture, tumbler, knife, fork, spoon, and cup. The other seven places pictured on the cue cards were the intersection of a highway and railroad, a group of animal cages, living room, workshop, classroom, refrigerator, and a bedroom with an open closet door. The pretest to assess naming and categorizing of the recall cards went as follows. Four cue cards were arranged in a row. Below each went four haphazardly arranged recall cards, forming a 4 X 4 matrix. The retarded person’s job was to name each of the 16 cards and then rearrange them so that the four which went with each cue card formed a column below it. This procedure was repeated until all 16 cue cards and all 64 recall cards were named and categorized by rearrangement. Only retarded people who did this pretest perfectly were included in the investigation, though this was not an important source of attrition. A pretest of free recall was used to insure that none of the retarded people could perform well on the criterion task prior to instruction. Our notion was that if we did not instruct the behaviors necessary for good criterion performance, we could not have reasonable confidence about how the people we studied solved the task. In other words, we chose to use instructional procedures in lieu of extensive task analysis and concurrent measurement during criterion perform-

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ance (cf. Belmont & Butterfield, in press), and this required us to show that our subjects needed instruction. We expected that they would perform poorly on this pretest, and they did. For the free recall pretest, we arranged four cue cards and 16 recall cards as during the naming and categorizing pretest, with four recall cards beneath each cue card. The subjects were given 2 minutes to study this array following these instructions: “In a little while we will ask you to tell us the names of the 16 little white pictures. You can use the big blue cards if you think they will help you remember the little white ones. You may do anything you want with the cards to help you remember them, like moving them around. You don’t have to do anything with the cards, but you may if you want to.” Following a 2-minute study period, the recall cards were covered, but the cue cards remained visible. The subjects were asked to recall as many of the 16 names of recall cards as they could. The criterion task at the end of the experiment was procedurally identical to this pretest, except that different cue and recall cards were used. A training procedure intervened between the free recall pretest and the criterion task. The purpose of the training procedure was to show us that the retarded people could study by category, and to show them how accurate their free recall of 16 cards could be if they did that. The training procedure consisted of two recall trials, identical to the recall pretest and the criterion task except that rearrangement of the cards was not permitted. One trial used a haphazardly arranged matrix of 16 recall items, and the other used a categorized matrix in which the items were arranged in columns of four under their conceptually related cue card. With the categorized matrix, subjects were instructed to study the items as groups and to use the cue cards in recalling the items. Recall under this condition was markedly superior to recall with the unorganized matrix. The criterion task started with a random matrix of 16 recall and four cue cards. To recall the 16 cards well, the subjects should have rearranged them according to the categories of the four cue cards, and then studied them as groups. The data showed that people who did rearrange the recall cards during the study period recalled according to the cue card categories. Considering each cue card’s four associated recall cards as a cluster, perfectly clustered recall would result in 12 adjacent, within-cluster item pairings. We adopted a criterion of seven clustered pairs to judge that a subject had passed this free recall task. By this criterion, 15 retarded people passed and 25 failed the free recall task. 2. MEMORY REORGANIZATION

The test for memory reorganization was modeled on the procedures of Salatas and Flavell (1975), and it took up where the free recall task, which it always followed, left off. Sometime following the free recall criterion task, the complete strategy that would have yielded high recall on it was taught. But for this task we used only 12 recall cards and three cue cards. A categorized matrix

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was presented repeatedly, with study instructions, until the subject recalled all 12 in perfect clusters of four. Then a second matrix of 12 was presented until recall was again perfectly clustered. The first set of items was presented with detailed instruction on the use of the study strategy, whereas the second set was presented only with prompting to adopt the strategy. The three cue cards for the critical second set pictured a playground, house, and beach. The recall items were a ball, jump rope, slide, swing, light bulb, ashtray, sink, bathtub, fish, seashell, boat, and lighthouse. Immediately after the perfect recall criterion was reached for the second set of 12 pictures, two questions were asked. The first was: “Which of the things that you just named are things that you cannot lift? Tell me all the things that you cannot lift.” The correct answer was slide, swing, sink, bathtub, boat, and lighthouse. Responding correctly required recategorizing the already clustered list. For the second question the person was shown a cardboard box and asked: “Which of the things that you named are things that will fit into this box? Tell me all of them.” The correct answer was ball, jump rope, light bulb, ashtray, fish, and seashell. Following the second answer, the recall cards were uncovered and the person was asked to point to “the ones you cannot lift” and then to “the ones which will fit in the box.” To answer these questions the subject had to run through his list of memorized things, using the exposed cue cards as guides, naming only those which fit each question. It called for him to combine two operations. The training preceding the questions assured that the person could recall all of the items in the list according to one set of categories (Operation 1) and the judgments called for after the questions assured that he could recategorize each item according t o the questions (Operation 2.). Perfect application of this strategy would yield, in response to each question, a list of six items clustered as three pairs. Since there were two questions, perfect application would yield six clustered pairs of items. The criterion which we used to infer success was output of four of the six possible clustered pairs. By this criterion, 15 of our subjects passed and 25 failed the memory reorganization test. In summary, this experiment asked institutionalized mentally retarded people to perform four tasks, each of which required combining two component cognitive behaviors. The inferential behavior task asked for the combination of (1) a discriminative lever pulling response to secure a large marble and (2) a marble inserting response to secure gum. The sequence counting task required the retarded person (1) to recall a serial sequence of pictures in order (2) to count how many fell between two pictures provided by the experimenter. The free recall task required the subjects (1) to organize a group of 16 pictures into four categories and then (2) study them as categorized groups for subsequent recall. The recategorizing experiment required (1) covert categorized recall of a list of 12 items and (2) overt naming of the items which fell into categories

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which cut across the learned ones. The experimental question was whether performance covaried across all four of these cognitive combining tests. 3. RESULTS

Like Ashby’s normal children, our mentally retarded adults were exactly on scale for the inferential behavior task. Unlike Ashby’s children, our mentally retarded adults were completely off scale for sequence counting. Thus, the first thing our results showed was a task problem for sequence counting. The difficulty was apparent even during training to put cards between two supplied by the experimenter. Nearly half of the retarded people never did this. Their problem was not one of memory, since the sequence to be reproduced was visible to them. It was as if they did not understand “putting the cards between.” This half of the subjects remained on the measurement floor because failing training on sequencing precluded administering the criterion task of counting from a memorized sequence. The other retarded people mastered training satisfactorily, but all save one also passed the criterion task. We thus obtained only half the possible sequence counting data, and virtually all of them were on the measurement ceiling. We were left with no variance in sequence counting to relate to variability on the other measures. With respect t o sequence counting, the theory failed this experiment. In doing so, it showed that the requirement of understanding each task amounts to requiring an analysis of it for each subject population to which it will be applied. None of the other three measures suffered such task problems. Table I1 shows the data from which our cross-task comparisons were made. It gives, in the “Observed” column, the number of retarded people who fell into each of the eight possible pass/fad combinations of the three criterion tasks. Thus, the top TABLE I1 OBSERVED AND EXPECTED FREQUENCY OF EACH POSSIBLE PASS/FAIL COMBINATION O F THREE EXPERIMENTAL TASKS BY 40 INSTITUTIONALIZED MENTALLY RETARDED ADULTS

Inferential behavior

Free recall

Memory recategorization

Pass Pass Pass Pass Fail Fail Fail Fail

Pass Pass Fail Fail Pass Pass Fail Fail

Pass Fail Pass Fail Pass Fail Pass Fail

Observed

Expected

11 8 2 6 1 4 1

6.08 10.12 4.05 6.15

I

2.9 4.88 1.95 3.25

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row shows the number of people who passed all three tasks, and the bottom row shows the number who failed all three tasks. The table also shows, in the

“Expected” column, the number of people who would have fallen in each passlfail combination if performance on the three tasks were independent. By the standards of individual difference experiments, this one would be absolutely successful only if all of its subjects fell in the top and bottom rows of Table 11; all would either pass all three tasks or fail all three. Chi-square analysis shows that the results ran significantly in t h i s direction (x’ = 11.75, p < .001). Only the pass/pass/pass and fail/fail/fail categories exceeded the rates expected for them by chance. But inspection suggests the shortcoming of significance tests: A large number of people fell in the discordant (mixed pass and fail) categories. Taking the tasks two at a time and comparing their covariances to that yielded by Ashby’s two tasks illustrates the problem. Pairwise comparisons of the pass/fail correlations of this experiment’s three tasks show: inferential wrsus free recall k2= 3.72, C = .29); inferential versus recategorization @ = 4.01, C = .30); and recategorization versus free recall (x2 = 3.00, C = .30). For each comparison, chi square lies near significance: p = .05 at x2 = 3.84. The three contingency coefficients are highly similar and can be compared directly to Ashby’s. They lie just above half of his value of .57, where the maximum possible is .7 1. Whereas Ashby secured convincingly high covariances, these are unconvincingly low. What are we to make of these results, and their contrast with Ashby’s? The problem with these data is not that they run counter to our theoretical expectations. They fall significantly in the predicted direction. The problem is that they yielded contingency coefficients too low to convince us by themselves that our tasks tapped a unitary process. By exposing it to task and person tests we have shown the incompleteness of the theory which says it is important that during middle childhood people begin to combine cognitive operations into plans for solving problems (Dickerson ef al., 1975). The task problem presented by the sequence counting procedure is undeniable. About the person problem we have only soft data. Subjects’ motivation seemed to change from day to day. One day, a person would seem happy to see us and be eager to do the procedure of the moment. Another day, he would be generally uncooperative. Our postexperimental inquiries suggested that on some days our scheduling of experimental sessions had interrupted valued activities, while on other days it rescued our subjects from unpleasant duties. Performance seemed to vary accordingly. We concluded that Ashby’s findings are sufficient evidence for the process of combining cognitive operations to justify further test of the theory that prompted his experiment. Our findings are sufficient evidence that further task analysis and attention to person variables are needed before those further tests are made. The theory needs to be more complete.

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F. Probability of Widespread Use

So far, few experiments have conformed to the requirements of individual difference tests. We liken the present standing of individual difference tests to that of a research strategy which was being advocated for developmental and comparative studies of mental functioning in the mid-1960s. Prior to that time, main effects of age and intelligence on single tasks were often attributed to process differences between the groups differing in age or IQ. Then we were introduced to the alternative of showing interactions between experimentally manipulated variables and age (Gollin, 1965) or intelligence (Baumeister, 1967). The notion was that simple age and IQ effects implicate no particular process, but showing interactions with variables known to influence some process does allow inferences about how different groups of people compare on it. This argument has been widely accepted. It seems to us that the practical constraints on investigators who would use individual difference tests are just now being explored, but that they will be mastered and this approach too may be widely used. We are not suggesting that individual difference tests should replace the strategy of showing Group X Task Variation interactions. The two approaches are complementary. Individual difference tests are intended to define and verify the existence of a theoretical process, and to show that the process accounts for differences between particular people. An interaction of Group X Task Variation intends to show that an identified process can account in part for differences between classes of individuals. Both functions are needed in a complete science of cognition.

V. COGNITIVE INSTRUCTION

Simon noted that ‘ I . . . one can undertake, by training and instructions, to If we are to understand influence subjects in their choice of strategies.. human problem-solving behavior, we must get a solid grip on the strategies that underlie i t . . . Whether we have that grip for any particular behavior can be tested convincingly by cognitive instruction, and the behaviors for which the tool will work include far more than problem solving as it has usually been construed by psychologists. Students of normal development and of retardation have shown that successful cognitive instruction can validate our understanding of memory (Butterfield er d , 1973) learning (Turnure, Buium, & Thurlow, 1975), scientific inference (Siegler & Liebert, 1975; Siegler, Liebert, & Liebert, 1973), the Piagetian conservations (Kuhn, 1974), and a host of other cognitive capabilities (cf. Belmont & Butterfield, in press). But it calls for a new set of

..

.”

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scientific attitudes, and it comprises a demanding group of techniques whose requirements are only now coming clear. A. Pressures for I t s Use

Unlike students of normal development and mental retardation, most students of normal adults’ cognition have not yet shown their readiness to accept cognitive training as an experimental tool. We have found only one report of experiments on normal adults which approximately meet the requirements of effective cognitive instruction, and we doubt that its authors (Craik & Tulving, 1975) conceive of their experiments as instructional. They suggest that their procedures are “incidental orienting tasks.” There are few concrete signs that cognitive training will soon be seen as a necessary supplement to current experimental techniques for the study of adults, whereas there were many for individual difference tests. Simon (1975) is almost alone in suggesting the value of cognitive instruction for the study of adults. His argument was based on a priori considerations rather than on a demonstration of feasibility, and he was concerned with problem solving rather than with cognition in general. But a case can be made that cognitive instruction may nevertheless be widely accepted. First, there is a need for it. The usual approach of cognitive scientists has been to evaluate behavioral changes that result from experimental conditions which might influence people’s mental approach to laboratory tasks. The experimental conditions are commonly called treatments, but this is a misnomer since no overt attempt is made to change the cognitive processes of interest. Rather, the treatments are covert invitations to use cognitive processes to different degrees. The purpose of such experiments is diagnostic in the sense that they aim to assess whether people take more or less advantage of the cognitive possibilities that happen to inhere in the conditions. Such indirect procedures must necessarily have smaller effects than well-informed direct manipulations of the processes of interest. Thus, the source of the enthusiasm which Craik and Tulving (1975) expressed over their findings was the largeness of their effects relative to those of diagnostic experiments. While they did not identify their efforts as instructional, they emphasized that the purpose of their manipulations was to change mental processes. Other cognitive psychologists may soon see that directly instructing cognition will yield irresistibly large experimental effects. Moreover, cognitive instruction is solidly in the experimental tradition of laboratory scientists. They cannot stay happy for long with diagnostic, which is to say observational approaches to their subject matter, once they appreciate the availability of the alternative, which is direct experimental manipulation. As laboratory scientists, they must inevitably realize that their theories can only be strongly affirmed when they begin to manipulate their explanatory processes.

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Since their explanatory mechanisms reside in the head, we expect that cognitive science will come to rely on cognitive instruction. B. Methodological Requirements

Successful instructional experiments require reasonably complete task analyses. Unless the experimenter has a complete understanding of the important cognitive requirements of his criterion tasks, he cannot fashion instructional routines for their solution. The nature of the requisite task analyses will vary with the experimenter’s purpose. When the purpose is to evaluate an understanding of the development of mature thinking, the experimenter will need analyses of how both immature and mature information processors attack his criterion task. Then, the instructions he must use to make immature thinkers solve the task like mature ones are one account of how mature thinking develops. An alternative way of expressing the purpose of such an experiment is to say that it tests the completeness of the experimenter’s understanding of mature task solution. The second requirement is standards against which to evaluate the effect of instruction. The nature of the standards will vary with the experimenter’s purpose, but the simplest concerns the magnitude of the instructional effect. When the purpose is to test a theory of cognitive development, this standard can be established experimentally by testing a group of mature information processors. Applying the standard then amounts to seeing whether an instructed immature group achieves the performance level of the uninstructed mature group. A training experiment is completely informative only when it raises its immature subjects’ performance all the way to the standard set by its mature reference group. Harking back to our alternative way of expessing the first requirement, we can say that training immature people only affirms the completeness of an investigator’s understanding of a mature strategy if it brings immature people all the way to the mature standard of performance. If a training experiment does not raise performance all the way to its appropriate standard, then it will be informative only if it provides independent evidence that its instructions actually affect underlying cognitive processing as they are supposed to. The experimenter must be able to determine whether a failure to raise criterion performance to the desired standard actually discredits his understanding of the processes underlying mature performance, or whether the training failed by virtue of not producing the called for processing. Training experiments need to include dependent measures which supplement their assessments of criterion performance by showing whether the instructions in fact led subjects to adopt the intended information-processing strategies. Training experiments will fail to raise performance enough whenever they are based on inade-

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quate criterion task analysis, but the only way to know that the analysis is inadequate is to be certain that it was actually implemented by the instructions. C. Two Instructional Experiments

Cognitive instruction is a developing technique, and we still have much to learn about its use. But it has been used successfully already. Here are two examples to show how instruction can test cognitive theory. Kobasigawa (1974) used instruction to test his understanding of how mature information processors use conceptual information to retrieve items from memory. His criterion measure was derived from a free recall task. All of his subjects were shown how to cluster items into conceptual categories at the time of input, and how to associate each of the clusters with a label. These were not the instructions of interest; they were used only to insure comparability of input processing among his various age groups. His three groups were normal children, ages 6, 9, and 12. For purposes of this experiment, the standard of mature information processing was established by 12-year-olds. The instruction of interest in Kobasigawa’s experiment concerned how to use conceptual information at the time of recall. One-third of the children were given no retrieval training. They received standard free recall instructions. Another third of the children were given retrieval cues in the form of category labels that had been present during input. They were shown that they could use the category labels as retrieval cues. The remaining children were given retrieval cues too, but in addition they were instructed to use them systematically. They were to look at a cue and try to recall all of the items that went with it before looking at another cue and recalling the items that went with it. Thus, there were three conditions for each of the ages studies: free, cued, and systematic recall. The lists in this experiment were 24 items long. They had three instances of each of 8 conceptual categories. Under free recall or control condition, 6-yearolds recalled fewer than 10 items per list, while 12-year-oldsrecalled nearly 20. Plain cuing had no effect on the performance of 6-year-olds and very little effect on 9-year-olds. Systematic cuing led both 6- and 9-year-olds to recall just over 20 items per list, which was identical to 12-year-olds’accuracy. Kobasigawa’s (1974) experiment is convincing proof of how 12-year-olds,and probably adults, use categorical information during recall. When during input, they have stored items along with a category label, they systematically use those category labels at output to guide the retrieval of the items from long-term memory. Six-year-olds differ from 12-year-olds primarily with respect to how systematically they use retrieval cues. The only shortcoming of Kobasigawa’s experiment was its failure to employ supplementary measures of whether children followed his instructions. Had he

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failed to bring the criterion performance of 6- and 9-year-olds up to the level of 12-year-olds, it would have been difficult to know why. It would have been difficult to determine whether his experiment was a satisfactory test of his understanding, or whether his procedures were an imperfect implementation of it. Another use of cognitive training was reported by Butterfield et ul. (1973). It meets the requirements of cognitive training experiments. It taught mentally retarded adolescents how to perform a &item probe recall task as accurately as uninstructed normal adults. Its training procedures were derived directly from analyses of adult’s, children’s, and mentally retarded people’s performance. In general, the analyses showed that adults combine attention and rehearsal mechanisms to store a list’s initial items in long-term memory. Then they use attention alone to put terminal items into a short-term storage buffer. At recall, when a probe item is presented, they first decide whether it is represented in their short-term buffer. If it is, they respond. If it is not, they then retrieve the representation of the items from long-term memory and search them for the location of the probe. Experiments with mentally retarded people had shown that they use little rehearsal during input. So, we first taught mentally retarded adolescents how to combine attention and rehearsal. This improved their recall, but still they did less well than adults. Measures of pausing during learning showed that our training procedures had the desired effect on input. The instructed retarded people had done as adults do at input, but still needed help. We then taught them about the various output mechanisms which we knew adults used. This improved their recall further, but they were still less accurate than adults. Their criterion performance went up more, but not all the way to our adult standard. Response latency measures showed that this was because they did not use the instructed retrieval processes as adults do. According to our supplementary measures, the instructed retarded people sometimes searched for their representations of rehearsed initial items before they searched for the terminal unrehearsed items. This caused them to do very poorly on the terminal items. Therefore, we taught them how to sequence and combine their searches of short-term and long-term memory. At this point, they performed insignificantly better than uninstructed normal adults. Measures independent of recall showed that they had used the instructed cognitive strategies at both input and output. D. Unanswered Questions of Uw

Clearly, these two illustrative experiments do not exhaust the possibilities of cognitive training. We cite them because they represent successful uses of the instructional approach for the general purposes to which it has so far been put: helping increase understanding of cognitive development and mental retardation. The instructions which were required to raise mentally retarded people to the

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normal adult standard showed that retarded people lack none of the cognitive mechanisms required for mature recall of the sort studied. Moreover, they were easily trained, even though the strategy given them was a complex combination of several cognitive mechanisms. The cardinal deficit of these mentally retarded subjects, which we see no way to have discovered except by using instruction, was in their coordination of cognitive tactics. It was not enough to show them the mechanisms required for task solution. They had to be shown every detail of how to combine the mechanisms, and pursuing that discovery has led to other findings about the ways in which people select and combine tactics to meet changing task demands (Butterfield & Belmont, in press). But even in aggregate, all of the instructional experiments we know leave important unanswered questions of use. Consider the problem of setting standards for the instruction of normal adults. The standard of uninstructed adult performance will not do. Adults d o not need instruction to make them perform like adults. One approach is to instruct adults to use immature strategies while maintaining performance of an immature group as the standard (cf. Belmont & Butterfield, 1971). This approach can increase understanding of the development of cognition by showing that thought can be made less mature with the converse of instructions which make it more mature. But it leaves untouched many questions about adult cognition, questions of capacity, for instance. We can think of no question to which instruction might be turned more naturally than how much information can adults process. But what standard should we maintain for the success of efforts to estimate capacity by instruction? Belmont and Butterfield (in press) have suggested a standard called the theoretical maximum possible performance. It comes in two varieties: the ceiling of the measurement scale and the best performance ever observed on the task in question. About the first variety, they say: “The scale ceiling is a purely anomalous, will-0-the-wisp standard. The argument in its favor is that perfect performance cannot be improved upon. . . The difficulty in this position is that the ceiling is a scale limit. It is not a limit on the psychological dimension which we assume the scale is reflecting.” This maximum possible performance will not serve as a standard for judging success at estimating capacity, because simply expanding the scale by raising the ceiling would increase the possible limits of capacity. About the second variety, Belmont and Butterfield point out: “If we abandon the ceiling as a standard for evaluating instructional effects, we are left with only one maximum possible performance level-the best performance ever observed on the task in question. If instructions have not previously been used with the task, then this maximum will be the best performance ever turned in by an uninstructed subject. If task analysis has ever been done at all systematically, however, it will have been found that even the best uninstructed performance is well below the maximum possible obtainable by instructions.”

.

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For example, Wallace, Turner, and Perkins (1957) attempted to probe capacity for learning pairs of items under interactive imagery instructions. They reported that adults, given single learning trials, began falling below the measurement ceiling only when 500 pairs were presented. Performance was still above 90% for 700 pairs, at which list length the number of hours in a day precluded further efforts to probe adult capacity. Perhaps the capacity question is an absurd one, and we should not concern ourselves with standards that might allow its successful evaluation by cognitive instruction. We think it is not so simple as that. While we have no answer to how one decides when he has accurately estimated capacity, considering how far performance can be increased by instruction certainly puts fresh perspective on other approaches to studying cognition. Consider the vast literature recently reviewed by Borkowski and Wanschura (1974) on what underlies effective paired-associates learning. This literature grew up only after the demonstration by Wallace et al., yet increasing performance t o 15 or 20 pairs was considered worthy of report. Surely the effects achieved in 1957 say that the instructional alternative to diagnostic techniques should be tried. Despite many unanswered questions of use, we expect that students of adult cognition will adopt a more manipulative approach to their subject matter, which leads us to consider why they have not done that yet.

VI. POSTSCRIPT

By normal adult standards, mentally retarded people and normal children share the distinction of being deficient information processors. Therefore, it is natural for those who study mentally retarded people to use the techniques of developmentalists, and vice versa. In fact, we view developmental cognitive psychology as a complex mix of work on normal mental development and work on mental retardation. Consequently, it should not seem peculiar that our illustrations of individual difference tests and instruction drew equally on experiments with average children and mentally retarded people. It might seem unusual that none of our examples were of experiments with normal adults, who comprise the vast bulk of subjects for cognitive psychological experiments. The explanation does not lie in the fact that we study developmental processes; though we do, we also study normal adults, and we depend heavily on the normal adult literature. The explanation lies in the fact that practically all individual difference and instruction experiments have been done with either children or mentally retarded people. There is a very large number of research reports in the literature on children and mentally retarded people that have either considered or actually used instruction. Our reading of the literature on adults says it has many fewer. Why this might be is the subject of this postscript.

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The study of adult cognition seems to have six important ancestors: neobehaviorism, verbal learning, human engineering, computer science, linguistics, and communication engineering (Lachman et al., in press). The first three of those ancestors gave cognitive psychology its laboratory tradition. Only one of them, human engineering, selected its problems for their practical value. None of the other three has inclined it toward practical problems either. Cognitive psychology has sided with its ancestors who selected their research topics for theoretical reasons, and this seems to account for its failure to pick up more quickly on cognitive instruction, which has been in the developmental literature at least since Pyles’ (1932) foray into its intricacies. Developmental psychology, on the other hand, necessarily concerns itself directly with two important practical problems. One is youth and the other is mental retardation. People afflicted with either of these problems constantly remind their observers that individual differences and cognitive instruction need understanding. The point is that general experimental psychologists and developmental psychologists have different traditions, and tracing those traditions can show both alternative approaches t o its subject matter. ACXNOWLEDGMENTS

This chapter w a s prepared while the authors were supported by U.S. Public Health Service Grants HD-00870, HD08911,HD-00084,and HD-02528. Eugene Goldfield, Dennis S i d i , and Laura Butterfield contributed importantly by collecting and analyzing the data reported in Section IV of this chapter. Edward Stull, Edward Benjamin, and other staff members of the Southbury Training School greatly facilitated that data collection by providing experimental space and access to mentally retarded people. Mary Carrigan, Carol Service, and Stella Stemmons provided secretarial assistance. John Belmont, John Borkowski, and Michael Karchmer criticized earlier drafts. REFERENCES Anders, T. R. Retrospective reports of retrieval from short-term memory. Journal of Experimental Psychology, 1971,90,251-257. Ashby, S. J. The development of the ability to combine activities in problem solving. Unpublished doctoral dissertation, University of Connecticut, 1976. Atkinson, R. C., & Shiffrin, R. M. Human memory: A proposed system and its control processes. In K. Sepnce & J. Spence (Eds.), The psychology of learning and motivation. Vol. 2. New York: Academic Press, 1969.Pp. 90-197. Battig. W. F. Within-individual diflerences in “cognitive” processes. In R. L. Solso (Ed.), Information pmcessingand cognition. Hillsdale. N. J.: Erlbaum, 1975.Pp. 195-228. Baumeister, A. A. Problems in comparative studies of mental retardates and normals. American Journal of Mental Deficiency, 1967,71,869-875. Belmont, J. M., & Butterfield, E. C. Learning strategies as determinants of memory deficiencies. Cognitive PsycholoAy, 1971,2,411-420. Belmont, J. M., & Butterfield, E. C. The instructional approach to developmental cognitive

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Lachman, R., Butterfield, E. C.. Dooling, J., & Mistler-Lachman, J. Cognitive psychology and information processing: An introduction. Hillsdale, N.J.: Erlbaum, in press, Lieberman, P. The evolution of speech and language. In J. F. Kavanagh & J. E. Cutting (Eds.), The role of speech in language. Cambridge, Mass: MIT Press, 1975. Pp. 83-106. Milner, B. Amnesia following operation on the temporal lobes. In 0. L. Zangwill and C. W. M. Whitty (Eds), Amnesia. London and Washington, D.C.: Butterworth, 1967. Pp. 109-133. Moely, B. E., Olson, F. A., Halwes, T. G., & Flavell, J. H. Production deficiency in young children’s clustered recall. Developmental Psychology, 1969, 1, 26-34. Newell, A. You can’t play 20 questions with nature and win: Projective comments on the papers of this symposium. In W. Chase (Ed.), Visual information processing. New York: Academic Press, 1973. Pp. 283-308. Postman, L. Verbal learning and memory. Annual Review of Psychology, 1975, 26, 291-336. Pyles, M. Verbalization as a factor in learning. Child Development, 1932, 3,108-113. Reitman, W. What does it take to remember? In D. A. Norman (Ed.), Models of human memory. New York: Academic Press, 1969. Pp. 470-510. Restle, F., Shiffrin, R. H., Castellan, N. J., Lindman, H. R., & Pisoni, P. B. (Eds.), Cognitive theory. Vol. 1. Hillsdale, N.J.: Erlbaum, 1975. Salatas, H., & Flavell, J. H. Behavioral and metamnemonic indicators of strategic behaviors under remember instructions in Fist grade. Unpublished manuscript, University of Minnesota, 1975. Segal, E. M., & Lachman, R. Complex behavior or hgher mental process: Is there a paradigm shift? American Psychologist, 1972,27,46-55. Siegler, R. S., Liebert, D. E., & Liebert, R. M. lnhelder and Piaget’s pendulum problem: Teaching preadolescents to act as scientists. Developmental Psychology, 1973, 9, 97-101. Siegler, R. S., & Liebert, R. M. Acquisition of formal scientific reasoning by 10- and 13-year-olds: Designing a factorial experiment. Developmental Psychology, 1975, 11, 401-402. Simon, H. A. The functional equivalence of problem solving skills. Cognitive Psychology, 1975,7,268-288. Skinner, B. F. Verbal behnvior. New York: Appleton, 1957. Solso, R. L. (Ed.) Contemporary issues in cognitive psychology. Washington, D.C.: Winston, 1973. Solso, R. L. (Ed.) Theories in cognitive psychology. Potomac, Md.: Erlbaum, 1974. Solso, R. L. (Ed.) Information processing and cognition. Hillsdale, N.J.: Erlbaum, 1975. Spitz, H. H. Field theory in mental deficiency. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963, Pp. 11-40. Turnure, J., Buium, N., & Thurlow, M. The production deficiency model of verbal elaboration: Some contrary findings and conceptual complexities. Research Report No. 82, Research, Development and Demonstration Center in Education of Handicapped chidren, University of Minnesota, January 1975. Underwood, B. J. lndividual differences as a crucible in theory construction. American Aychologist, 1975,30, 128-134. Wallace, W. H., Turner, S. H., & Perkins, C. C. Preliminary studies of human information storage. DA Project No. 3-99-12-023, SC Project No. 1320 for the U.S. Army Signal Engineering Laboratories, Fort Monmouth, N.J. (University of Pennsylvania, Institute for Cooperative Research, Philadelphia, 1957). Weimer, W. B. Overview of a cognitive conspiracy: reflections on the volume. In W. B.

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Weimer & D. S. Palermo (Eds.), Cognition and the symbolic processes. Hillsdale, N.J.: Erlbaum, 1974. Pp. 4 1 5 4 4 2 . Weimer, W. B., & Palermo, D. S. (Eds.) Cognition and the symbolic processes. Hillsdale, N.J.: Erlbaum, 1974. Zeaman,D., & House, B. J. The role of attention in retardate discrimination learning. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963. Pp. 15 9-22 1.

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A Decade of Experimenhl Research in Mental Retardation in India ARUN K. SEN DEPARTMENT OF PSYCHOLOGY UNIVERSITY OF DELHI, DELHI, INDIA

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1. Introduction 11. Research ..................................................... A. Cultural Deprivation .......................................... B. LearningandMemory ......................................... C. Factors Affecting Distractibility ................................. D. Otherstudies 111. AnOverview .................................................. lV. Conclusion References

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1. INTRODUCTION

In every country there are some children and adults who are mentally retarded. In India, no reliable statistics are available regarding the prevalence of mental retardation. India is a vast country with 550 million people, and any proposal for a national survey of all of India will be met with the insuperable difficulties regarding necessary financial outlay and the personnel required to conduct the survey. From the findings of a few random sample surveys in different cities like Bombay, Calcutta, Delhi, Mysore, and Nagpur, and also in accordance with the world rate of prevalence, the retarded population in India could be anywhere between 15 and 22 million. For a long time the stigma of mental retardation led families in India to conceal the existence of a mentally retarded child. Even as recently as 15 years ago, mental deficiency was a topic which aroused little interest in the general public or among physicians and psychologists. Psychology as an independent 139

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subject at the master’s level was first introduced in India in 1916 at the University of Calcutta, but until 1960 mental retardation was a neglected field of study. b a t h (1951), however, made a survey while standardizing the Binet test for Kanada-speaking people, but it was initially due to the experimental works of Das (1961a, 1961b) and Deb (1962) that the situation began t o change. At present, there are approximately 100 universities in India, out of which as many as 35 are giving training in psychology at the master’s and doctoral levels; and a few universities, e.g., Calcutta, Delhi, Kashi Vidyapeet (Varanasi), have started courses of study in mental retardation as well. The first All-India Conference on mental retardation was organized by voluntary societies and was inaugurated by the Prime Minister, Mrs. Gandhi, in New Delhi in November 1966. In her inaugural speech, Mrs. Gandhi said, “I fully realize that the Government has a good deal of responsibility in this respect. . . . I am sure the Government will do its best to help, especially in the field of research, which is more difficult for any private organizations.” Subsequently, several All India Conferences on mental retardation were held in different cities, viz., Bombay in 1968, Delhi University in 1969, Bangalore in 1970, Lucknow in 1971, Ahmedabad in 1973, and New Delhi in 1975. The total number of experimental research publications by the Indian psychologists in the field of mental retardation during the last decade has also exceeded 50, with a maximum number (about 25%)in the year 1968. The first Indian journal in the field of mental retardation was the Occupational Therapy Journal, now called The Journal of Rehabilitation in Asia, appeared in 1960 from Bombay. The Indian Journal of Mental Retardation, published by the All-India Association on Mental Retardation, Chandigarh, is another research journal which appeared in 1968. A popular journal entitled Mental Returdation Digest is being published by the Federation for the Welfare of the Mentally Retarded, New Delhi, since 1970. At present, there are 9 1 institutions altogether in 22 states and 9 union territories. Though there are a few excellently run institutions at centers like Ahmedbad, Bangalore, Bombay, Calcutta, and Delhi, they are capable of caring for a total of only about 4000 retardates. Recently, in the fifth 5-year plan a National Institute for the Retarded has been established by the central government at Bon-Hooghly, West Bengal. The Ministry of Social Welfare and also other government organizations like National Council for Educational Research and Training (NCERT) are potential agencies who are giving generous grants for the welfare of the retardates and research in this area. Quite a few students have enrolled for Ph.D. work in the field of mental retardation, and they are carrying out experiments at different institutions for mental retardates. Looking into these existing facilities, it appears that there has been an expansion during the last decade.

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II. RESEARCH

Ganguli (197 l), while surveying research publications of Indian psychologists, presented a list of 1950 studies in various psychological fields of fundamental and applied research during the period 1920-1967. But he did not mention the number of publications in the field of mental retardation. The Indian Council of Social Science Research (ICSSR) appointed a selected group of 10 psychologists as editors for conducting a survey of research in psychology in India in 10 different subfields. The report entitled A Survey of Research in Psychology was published in 1972. The editors were: S . K. Mitra for Methodology and Research Technology; R. N. Rath for Social Psychology; M. M. Sinha for Physiological and Comparative Psychology; T. E. Shanmugam for Personality; A. K. P. Sinha for Military Psychology; D. Sinha for Industrial Psychology; V. K. Kothurkar for Experimental Psychology; M. B. Buch for Educational Psychology; E. G . Parameswaran for Developmental Psychology; and B. Krishnan for Clinical Psychology. The report is an important document and a useful baseline for the Indian psychologists, but the area of mental retardation should have been considered as one of the subfields. When Das (1968b) reviewed research, care, training, and rehabilitation programs in mental retardation in India, he came across only five experimental studies up to the year 1965 (Das, 1961a,b, 1965; Deb, 1962, 1964). The last decade has, however, witnessed an increased interest in experimental research in mental retardation, and the number of publications has also increased considerably. The aim of the present author, therefore, is to present experimental research in this field for a period of 10 years from 1966 to spring 1975. The author was able to span about 50 published works which occurred during this period. Other findings, such as medical research, surveys, care, training, guidance, public attitude, rehabilitation programs, etc., which are also available in the literature, are not included in the present review. The author, however, did not cope with the question of quality of experimental research in mental retardation in India. There seems little reason to discuss the quality of research until it is clearly demonstrated that experimental research in mental retardation, is, in fact, occurring in India. If further research consistently yields a large number of publications, the question of quality should then be considered. Quite a few experiments mentioned in this review were conducted by Indians abroad. Since the investigators have developed further research along these lines in India, these are also presented. In collecting the list of publications from the different journals during the last decade, some inadvertent omissions may have been made, but the probability of that being a major contribution t o mental retardation in India is small. A. Cultural Deprivation

The term “cultural deprivation” is a euphemism (Hurley, 1969). It is often used interchangeably with other terms such as “disadvantaged” or “underprivi-

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leged”, which have appeared in a number of different contexts. However, in the United States, cultural deprivation is predominantly noticeable in low socioeconomic groups, and according to Hurley almost 100% of the poor are culturally deprived. But in India, according to Das (1968a), caste is also an important factor in addition to economic status in defining cultural deprivation. The highest caste Brahmin and the lowest caste Harijan have been separated by birth for generations and that birth in a high caste may compensate for poverty. A specific study in this area made by Das et d. (1970) supported this. The samples were drawn from the municipal schools of the city of Bhubaneswar, India. Brahmin and Harijan children were selected from the schools on the basis of the socioeconomic status of their parents. The cutoff point for rich and poor was monthly income above or below 200 rupees. The low-income group included office boys, sweepers, petty clerks, farm laborers, and poor priests, whereas the relatively high income group included professors, engineers, administrative assistants, shopkeepers, and well-to-do priests. Subjects from the four cultural groups (Brahmins-rich and poor, Harijans-rich and poor) were closely matched for age and school class, and all were boys. They were given four tests: Raven’s Progressive Colored Matrices, the Stroop test (Stroop, 1935), a test for short-term memory, and a recognition test. There was an interval of approximately 2 months between the administration of the first two tests and the last two. The first two tests were administered in the classroom situation, but for memory and recognition experiments, subjects were brought to the psychological laboratory. Mean Progressive Matrices scores were 21.22 for rich Brahmins (N = 36), 19.30 for poor Brahmins, (N= 30), 19.38 for rich Harijans (N= 16), and 17.22 for poor Harijans (N = 36), revealing a hierarchy of rich Brahmins at the top, poor Harijans at the bottom, and rich Harijans and poor Brahmins with similar scores occupying a middle positoon. However, t-tests showed only the two extreme goups to be significantly different (p C .05). The Stroop test was scored following Jensen’s (1965) method. The results were interesting in that, in reading speed, the Brahmins excelled the Harijans, regardless of economic status, whereas in color-naming speed, the rich were superior to the poor. The wordreading speed showed the two high-caste groups to have similar speeds, which were faster than the corresponding scores for the two lowcaste groups 0,< .O 1). In color naming from the color chart, the rich, regardless of caste, had faster speeds than the poor 0,< .01). The short-term memory task consisted of listening to a random series of 10 digits from 0 to 9, presented from a magnetic tape at the rate of 1 second per digit, and to a pair of test digits following the series of 2 seconds. Subjects were asked to decide whether the test digits occurred in the preceding series in the given sequence. The test pairs were drawn from three positions in the series, the third, fifth, and seventh. Each pair of test digits was either a true one, that is, had actually been presented in the series, or a false one in which the first digit

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had occurred at one of the three positions, but the second had not. The results showed an increasing trend of recall scores from third to seventh position in the data from the two Brahmin groups, but not consistently in the Harijan group. For coding, the poor Harijans made the most errors, followed by the poor Brahmins, who appear to have made more errors than did the rich Brahmins. By and large, the t-test showed significantly (P < .01) lower recall scores for Harijans, and that errors in coding were also significantly (p < .05) higher for Harijans than for either of the high-caste groups. The regocnition task employed here was sunilar to that used by O’Connor and Hermelin (1963) with the exception that the investigators (Das et ~ l . 1970) , used only two of the four combinations: a unirnodal task, auditoryauditory, and a cross-modal one, visualauditory. The experiment yielded two scores for each subject: the number of correct recognitions for unimodal and for cross-modal tasks. The results showed that higher recognition scores for the unimodal task were significant for the poor Brahmins and poor Harijans, but not so for the rich Brahmins. All these studies thus revealed inferior performance by the low-caste children, and that caste appeared to be an important factor in defining cultural depriva. tion in a society like India. However, Raven’s Progressive Colored Matrices test and the Stroop test differentiated the groups more than that of short-term memory and recognition tests. On the whole, though there was a marked trend, all the results did not support clear-cut differences in ability due to either caste or economic status, Therefore, the next experiment (Panda & Das, 1970) in the series was conducted within the same four class/caste categories, but this time the rich and poor contrast was sharper. The groups were separated by an income gap of 300 rupees per month. Only the Stroop test was common between the experiments. In addition, two verbal-conditioning tasks, each measuring acquisition and reversal, were given to subjects in a random order. Latency of acquisition response was also recorded by a suitable arrangement of the apparatus. The results of the Stroop test were similar to those in the previous experiment except that the rich children from both high and low castes were superior in word reading. The authors believe that t h i s was due to the sharper rich-poor difference in income in the present group of subjects. In one verbal conditioning task (adjective test), the high-caste children irrespective of income were superior to the low-caste children in trials to learn and reverse. On the other task (light-press test) however, rich, irrespective of caste, was superior to the poor in trials to learn and to reverse. On the latency of responses, the high-caste children were faster than the low caste. They were also faster in speed of reading words in the Stroop test. By and large, this experiment demonstrated a general superiority of high caste and socioeconomic status in verbal ability, and a combination of these two yielded an enormous advantage in cognitive abilities. Jachuck and Mohanti (1974) administered Raven’s Progressive Coloured Matrices and Stroop test upon a group of 100 mentally retarded boys (50

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between 8 and 10 years and 50 between 14 and 16 years). Within each group equal numbers of subjects were taken from high socioeconomic status (fathers earned more than 600 rupees per month and were at least graduates), and low socioeconomic status (fathers’ income was less than 200 rupees per month and their education was below matriculation). Results clearly indicated that in both the age groups, subjects with high socioeconomic status performed both the tasks better than subjects with low socioeconomic status. The difference, however, was greater at the higher age group. The authors concluded that the low socioeconomic children suffer from a cumulative deficit (Das, 1973) in their cognitive competence rather than compensating for the earlier disadvantage. Summing up these findings, one can reasonably say that economic prosperity reflects more of an advantage than high-caste birth. All the poor are culturally deprived but not all the poor are mentally retarded. The relationship between cultural deprivation and mental retardation needs t o be clarified. It seems that the environment of the cell of poverty is the main cause of apparent retardation, and that to eradicate this type of retardation it will be necessary to attack every aspect of poverty. B. Learning and Memory

The dictum that memory is the foundation of learning and that all learning is based on memory is indisputable. In its broadest sense, the process of memory is commonly divided into three sections: (1) the phase of acquisition of material (learning phase), ( 2 ) the phase of retention, and (3) the phase of recognition or retention. The division is, of course, artificial, since all learning involves retention. It is customary to speak about learning when a short time elapses between acquisition and reproduction, and about retention when the interval is longer. Investigators unanimously hold the view, however, that memory is a thought process, in which all these aspects interact. With the revival of “decay theory” in psychology of normal individuals, there has been a great interest in the study of short-term memory. Ellis (1963, 1970) has extended the decay theory from a somewhat different point of view to account for differences in behavior between normals and retardates. His hypothesis involves the establishment of a functional relationship between stimulus trace (st) and central nervous system integrity (nr). He believes that amplitude and duration of stimulus trade are deficient in retardates due to lack of adequate reverberating circuits in the brain. A number of experiments were carried out in tlus area which supported the theory. 1. E X P O S U R E TIME

Of the various methods by which verbal recall is studied, the simplest situation is the free recall technique (Keppel, 1964). This involves presentation

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of a number of items and subsequent recall of them, in any order. The items in the series can be presented either simultaneously or successively. Using this technique, A. K. Sen (1966) studied the effect of amount of material and display time in simultaneous presentations in a group of 8 mentally retarded adults (mean CA = 21 years, mean IQ = 42). In a 2 X 2 design, 8 and 16 different pictures of common objects (such as a car, a spoon, a dog, etc.) mainly taken from Peabody Picture Vocabulary Test (Dunn, 1959) were presented under 8- and 16-second display times. The results showed better recall score for 16 pictures (p < .025) and that there was no significant difference between 8and 16-second exposure times. Subsequently, the exposure time was vaned from 8 seconds through 56 seconds (i.e., 8 seconds, 16 seconds, 24 seconds, 32 seconds, 48 seconds, and 56 seconds) for 16 simultaneously presented pictures upon the same group of subjects. Thus the average exposure rate vaned from .5 second to 3.5 seconds per picture, increasing .5 second between steps. The mean free recall scores under single presentation for different sets of pictures were: 4.28 (8 seconds), 5.43 (16 seconds), 5.86 (24 seconds), 8.28 (32 seconds), 8.28 (40seconds), 8.14 (48 seconds), and 8.14 (56 seconds). The result indicated that a 32-second display time was the optimum rate for 16 simultaneously presented pictures. In another experiment, A. K. Sen and A. Sen (1969b), presented 16 pictures simultaneously at a 32-second display time to a group of 10 retardates (mean CA = 24.4 years, mean MA = 8.1 years). On a single trial, the mean recall score was 7.40. After a week’s interval the same group of subjects was presented eight pictures, most of which were from the previous block of 16, under the same display time, i.e., 32 seconds. The inclusion of stimuli from the previous block to the latter one was determined on the basis of individual subject’s correct responses. The idea was to manipulate the factor of “personal association,” if any, and t o find out the recall score for the shorter block. The mean recall score was 5.50. The result thus again showed better recall scores (p < .01) for the larger block than the smaller one, though in terms of percentage, the trend was opposite. The authors explained the result in terms of increased attention in a more complex array of stimuli. The effect of rate in successive presentation of stimuli was also studied by A. K. Sen and A. Sen (1968a). Seven retarded adults (mean CA = 23 years, mean MA = 5.4 years) were shown seven sets of 10 pictures each, under seven different exposure rates, viz., .25, S O , .75, 1.0, 2.0, 4.0, and 8.0 second(s) per picture. The subjects’ exposure rates, picture sets, and the temporal factors were balanced by using a 7 X 7 Graeco-Latin square design. The mean percentage of recall for different exposure rates under free recall condition was: 18.6 (.25 seconds), 28.6 ( S O seconds), 34.3 (.75 seconds), 34.3 (1 second), 44.3 (2 seconds), 40.0 (4 seconds), and 36.6 (8 seconds). The results showed a significant difference (p < .001) in recall scores under different rates of presentation. Trend analysis further revealed that both “linear” and “quadratic” components

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were highly significant (p < .001 and < .01, respectively.) When the total score of the fmt half was compared with the total score of the second half of the series, no significant difference in the scores was obtained at .25, SO, .75, 1.0, and 2.0 seconds; but at 4- and 8-seconds exposure rates the recency effect was superior to the primacy effect (p < .01 and < .05, respectively). These experiments suggested that rate of representation is an important factor in the memory of the retarded. At faster rates poor recall score is caused by limited input capacity (O’Connor & Hermelin, 1965) and in slower rates by memory decay (Ellis, 1970). The trace is a modification of the organism which is not directly observed but is inferred from the facts of recall. The present experiments suggest that the strategies which may have been available to the subjects (depending upon their intelligence level) in attempting to deal with a fading trace have an important effect on subsequent recall under different exposure conditions. 2. LONG-TERM RETENTION

Long-term retention of two groups of retardates having different intelligence levels was compared in an experiment by A. K. Sen and A. Sen (1967a). There were eight adults in each group (mean CA = 24 years). The mean MA for the first group was 9.75 years and that for the other group was 5.5 years; the difference was highly significant (p < .001). Black outline drawings of eight common objects taken in slides were projected one at a time, so that each picture (4 inches square) was clearly visible to the subject. The presentation time was 2 seconds per picture with a 5-second interitem and 8-second intertrial interval. Serial anticipation method was followed, and three successive errorless reproductions of the series was taken as the criterion. The results showed that the low MA group took an average of 21.94 trials to learn the series as compared to 13.12 trials taken by the high MA group (p < .01). When the recall test was given after a fortnight, there was no difference between the two groups. The mean retention score of the high MA group was 5.87 (range 4-8) and that of the low MA group was 5.50 (range 4-8). In another experiment involving distraction condition, A. Sen and Clarke (1968a) found that though the mean number of trials required by the control and the experimental group, in a serial learning situation, were 18.56 and 35.66, respectively (p < .005); there was no difference in retention scores between the groups, after an interval of 1 month. These findings add support to the view that it is the degree of learning that determines memory rather than the ease with which the material is acquired in the first place. 3. TRACE INACCESSIBILITY

Inaccessibility of memory trace is one of the causes for forgetting in shortterm memory. If the trace of the stimulus is within the central nervous system, and if memory fails to reproduce it, the trace is described as inaccessible. Brown

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(1964) described an experiment which demonstrated the existence of trace inaccessibility in a group of university students. His results suggested that the subjects were able to take the information during presentation, but could not reproduce them, possibly because the trace was below the “recall threshold” at that moment. A. K. Sen and A. Sen (196%) designed an experiment to investigate whether this kind of behavior could be identified in mentally retarded persons and if so, whether some possible causes could be ascribed to this kind of behavior. the study was divided into three parts: (1)identification of trace inaccessibility in the subjects, (2) application of a serial recall test, and (3) analysis of the subjects excitability score applying a rating scale. In the first phase 16 pictures of common objects were presented in slides, successively with a projector to a group of 24 retarded adults. Immediately after single presentation, the subjects were asked to tell the name of the pictures, regardless of order. Two minutes were given for this immediate free recall. On the following day, the subjects were asked quite unexpectedly to recall the pictureq again. Though the mean recall score, as expected, was less after 24 hours than on immediate test, some of the subjects (about 40%) recalled one or more correct pictures at this later stage, which they had failed to recall during immediate test. This indicated that trace of the original information was inaccessible during immediate recall for the subjects. The subjects who showed this type of behavior were referred to as the “trace inaccessible group” and a matched control group was formed with the subjects who did not show this kind of behavior. For the sake of proper matching, seven subjects had to be excluded. Eight of the remaining 17 subjects formed the trace inaccessible group (mean CA = 22 years, mean MA = 6.4 years; mean memory span = 3.6); while the remaining nine, the control group (mean CA = 22 years, mean MA = 6.3 years, mean memory span = 3.6). In the second phase of the study, eight blocks of stimuli consisting of five pictures in each block (just above the subject’s memory span), were presented one after another and the subject’s recall score was noted. The exposure time was 2 seconds with an interstimulus interval of 1 second. The interblock interval was 1 minute, while recall time per block was 30 seconds. The errors made by the two groups during recall were differentiated into four kinds-transposition, omission, intrusion, and substitution The results showed that although the mean errors made by the groups were practically the same, the trace inaccessible group made comparatively more intrusion errors (p < .05) than the control group who made comparatively more omission errors (p < .05). From the test behavior of the subjects, a possibility of differentiating these two groups in terms of some personality factors arose. Therefore, in the third phase of this study, a rating scale (Claridge & O’Connor, 1957) was applied. All the subjects were rated independently by two judges-the supervisor and the class teacher, The analysis showed that the trace inaccessible group was significantly more “excitable” (p < .025) than the control group. The result of this experiment suggested a possible

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line of approach in the study of trace inaccessibility in mental retardates and its relation to memory and personality factors. 4. PAIRED-ASSOCIATE LEARNING AND TRANSFER

Paired-associate learning requires that a subject must learn to call one stimulus when he is presented with some other stimulus. An experiment was designed by A. K. Sen and A. Sen (1969a) to determine the effect of degree of prior learning on subsequent learning in a paired associate task. The materials used were paired color and animal pictures of A-B, A-C relationship. Twenty-four retarded adults were divided into three groups of eight subjects each under three different conditions. The mean CA and mean MA of the groups were: Group 1-24 years and 9.1 years; Group 2-23.5 years and 9 years; Group 3-24.6 years and 9 years. The task consisted of visual presentation of six pairs of stimuli, a “color” and an “animal” picture in each. The subjects were made to learn by the anticipation method. The six stimuli and responses for A-B were BLUE-LAMB, RED- BEAR, GREEN-CAMEL, YELLOW-HORSE, MAROON-CAT, and NAVY BLUE-TIGER. The second list, A-C, had the same stimuli, but different responses, viz., DOG, ELEPHANT, PIG, ZEBRA, RABBIT, and LION. The materials (4” X 4”) were framed on pieces of white cardboard (9” X 4”). The stimulus was exposed for 4 seconds, following which the stimulus and response were exposed together for an additional 4 seconds. Each trial w a s followed by a 20-second rest. In order to prevent serial learning, the pairs within a list were presented in random order in different trials. Three degrees of prior learning conditions were used. In one condition (control) no prior list was learned (0%); in another condition the prior list A-B was presented until three responses (50%) were anticipated correctly; and in the third condition, the list was presented until all of the six responses (100%) had been anticipated correctly. For all these conditions, the second list A-C was presented until the subjects anticipated four responses (66.67%) on a single trial. The mean trials to reach this criterion in the A-C paradigm were 9.00, 7.34, and 4.87, respectively under these three conditions. The results showed that with high degree of prior learning, a positive transfer operated in the learning of the second list, i.e., A-C (p < .01). Orthogonal comparisons further revealed that when the degree of prior learning was maximum (i.e., 100%) the group learned the second list faster than the control group 0, < .005). The first two conditions, however, did not differ significantly, though the trend was in favor of the group under 50% prior learning. Gandhi (1968) conducted an experiment to estimate the interaction resulting from the inclusion of various grades of deficiency in a single group. Seven children between 9 and 15 years were taken and records were made on eight variables, viz., speech, manners, recognition, general behavior, toilet habits, counting, personal needs, and sense of responsibility. In a 1-year study, the initial record was compared with the final. The result showed that the chances of positive learning

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in a heterogeneous group are more than that of negative learning. Roy (1971) studied reminiscence in retardates on a paired-associate task. Forty institutionalized subjects (mean IQ = 65.3, mean CA = 25.5 years) were presented with a list of paired-associate meaningful materials. The learning session consisted of one familiarization trial where the eight stimulus-response pairs were presented in the usual paired-associate technique, i.e., one reinforced anticipatory trial stimulus first and the same stimulus and a response pair next. This was followed by two nonreinforced trials where the stimuli were presented alone without being paired with responses. Learning was measured by nonreinforced trials. Retention was measured after 2 minutes or 24 hours, by recall and associative matching trials. The results indicated improvement in the reproduction of new responses, i.e., responses not given during the prerecall trials in the 24-hour group. A low negative correlation was found between digit span and delayed recall. Sen and Patnaik (1973) carried out an experiment on transfer of training upon a group of 20 retarded children (10 boys and 10 girls) using two equivalent sorting tasks A and B. The CA of the group was between 10 and 13 years, and IQ ranged between 45 and 65 (mean IQ = 55). Task A, taken from Clarke, Cooper, and Henny (1966) required the subject to sort 20 geometrical forms into five categories. The stimulus cards were a square, a crescent, an ellipse, a trapezium, and a parallelogram. In the 20 response cards, the geometrical designs differed in size as well as in the position on the card. Task B consisted of cards with nonmeaningful shapes. There were again five stimulus cards and 20 response cards, which differed from the stimulus cards only in size. Two groups of subjects (10 in each) matched on age, sex, IQ, and initial ability level were administered both the tasks, following a crossover design. One errorless sorting of the 20 response cards was taken as the criterion of learning. Results showed that all the subjects performed the task better in the second learning situation than the first. The mean trials to complete the tasks on the first occasion was 15.4 and that on the second occasion was 11.0 @ < .001). The mean error on the first occasion was 119.0 and that on the second occasion was 57.3 (p < .001). Sex difference in performance was insignificant. The study demonstrated that transfer from one task to the other equivalent task was sufficient enough to alter the second learning situation in such a way that mastery of the transfer task was rapid. This study was further extended by Bhalla and Sen (1975) by manipulating the difficulty level of the transfer task. In the previous experiment, both the tasks had equal difficulty level, whereas in this experiment the transfer tasks under three situations were either easier, or equivalent, or harder than the original learning task. The results showed that the transfer effect was most profound when the subjects were given an equivalent task in the second occasion (p < .001). Normal children did better than equal M A retardates in all situations (p < .01).

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5. MAZE LEARNING

Mohan and Sun (1972) undertook an experiment to find if mentally retarded subjects differ from normal children in learning to trace a simple finger maze. The responses were measured in terms of errors committed and total number of trials taken to learn the route. A group of 64 subjects (CA = 11-15 years) were selected from 250 children by administering Raven’s Progressive Coloured Matrices. Those who fell between 10th and 15th percentile were regarded as mentally retarded, while those between 45th and 65th percentile were retained as normals. The mean score of the retarded and normal children were 24 and 37 respectively. In the experimental situation, each subject was tested individually where he traced the finger maze blindfolded with his index finger. The results showed that the normals performed the task better than equal CA mental retardates. The mean trials for the normal and retardates were 5.2 and 17.0, while for errors were 14.2 and 60.2, respectively. The difference was highly significant (p < .01) for both the measures. 6. PROBABILITY LEARNING

Das and Bower (1973) tested 48 mentally retarded subjects (mean IQ = 70; mean CA = 15.92 years) in a probability learning task at two levels of uncertainty. The subject was required to anticipate x or y following the presentation of a cue word “man.” Probability of Occurrence for x was .90in one condition and .70 in the other; probability of y was .10 and .30, respectively. The probabilities were reversed in two counterbalanced conditions and separate groups of 12 subjects were randomly assigned to each of the four conditions. The results showed accelerated heart rate during the anticipation period when the subject was waiting for a confirmation or contradiction of his prediction, and a marked deceleration following the positive as well as the negative feedbacks. The authors interpreted acceleration as a sign of internal reflection and deceleration as that of attention to external events. 7. SERIAL POSITION EFFECTS

If a series of items is learned to mastery and the number of errors made in the course of leaming is plotted for each item in the series according to its position, a bowshaped serial position curve is obtained. McCrary and Hunter (1953) replotted some earlier data and conducted some experiments themselves on serial position curves. From their own results, as well as from an analysis of the earlier data, they found that when the serial position curve is plotted, not in terms of mean number of errors made at each serial position but the percentage of total errors occurring at each position, the curves were shown to be invariant with several manipulations of the verbal learning situation. A. K. Sen and A. Sen (1968b) studied this hypothesis under different conditions. In one condition, a

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group of eight retardates (mean CA = 23 years, mean MA = 10 years) and another group of eight severely retardates (mean CA = 23 years, mean MA = 5.4 years) were required to learn eight pictures (black outline drawings) of common objects by the serial anticipation method. The presentation time was 2 seconds per item (through projector), with 5-second interitem and 8-second intertrial intervals. The criterion was three successive errorless reproductions. When a comparison of the learning trials was made, it was found that the retarded subjects took an average of 13.12 trials to learn the series as compared with 21.94 trials taken by severely retarded subjects. The difference was highly significant (p < .01). To compare serial position curves, errors at each serial position for the two groups were examined once in terms of mean absolute errors, and again in terms of percentage of total errors for each subject at each serial position and then averaged over the group (Girardeau & Ellis,1964). The results showed that errors made in most of the serial positions by the two groups were pignificantly different when absolute numbeqs of errors were considered; but no significant difference between the groups was observed when percentage of errors was considered. Two overlapping curves were obtained. In another situation, two matched groups of nine subjects each (CA = 25.5 and 23.5 years, MA = 9 years) were taken, and they were randomly assigned to normal and distraction conditions. The task required the subjects to learn a list of eight common objects, presented successively with a projector. The distraction condition consisted of 15 common words other than stimuli, randomly recorded over and over again and presented to the subjects through the earphones. The results showed that the experimental group (who had to learn under distraction conditions) took an average of 35.66 trials as against the control group in whose case the average number of trials was 18.56. The mean difference was highly significant (p < .005). Error analysis in each serial position was made as before, and the percentage serial position curves became similar in nature, irrespective of normal and distraction conditions. These results thus supported the invariance generalization in respect to intelligence level and effect of distraction on the nature of serial position curves. However, a controversy regarding McCrary-Hunter hypothesis appears in a study made by Noble and Fuchs (1959), which suggested that the hypothesis cannot be extended to cover differences in ability levels of the subjects. An examination of the study by Girardeau and Ellis (1964) revealed that these investigators gave only 10 trials instead of making their subjects learn to a criterion of mastery. Girardeau and Ellis commented that constant trial procedure might be a determining factor for the findings being incompatible with McCrary-Hunter generalizations. To clarify the issue of constant trial procedure A. Sen and A. K. Sen (1970) studied serial position curves involving four trials in serial learning of eight pictures under normal and distraction conditions. A group of 27 retardates (mean CA = 24.5 years, mean M A = 9 years) were taken for this

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purpose. The subjects had to recall the stimuli under normal, meaningful, and meaningless distraction conditions. The results showed significant differences between the conditions (p < .001) as well as between trials (p < .001). To test the McCrary-Hunter hypothesis the error curves were analyzed once in terms of absolute errors made at each serial position, and again in terms of percentage of total errors following the method adopted by Girardeau and Ellis (1964). Though the absolute error curves differed significantly, in all the conditions the percentage serial position curves became similar in nature irrespective of normal or distraction conditions. However, it should be pointed out that Noble and Fuchs had different ability groups, whereas this particular experiment used the same group of subjects under different conditions. The different approach of these experiments deters one from coming to a firm conclusion. 8. VON RESTROFF

PHENOMENON

Isolation of items within a list normally produces an effect known as the Von Restroff Phenomenon. Von Restroff (1933) had shown that items which are in some way different or isolated from the rest of the material will be better remembered. Sen, Clarke, and Cooper (1968) carried out three experiments to examine the following conditions: (1) the effect of serial learning of two fully colored pictures, centrally placed, in a list of otherwise composed of black outline drawings; (2) the effect of position of fully colored isolated items peripherally placed on a list, and (3) the effect of reducing the degree of isolation by using red outline drawings instead of fully colored pictures, centrally placed, in a list otherwise composed of black outline drawings. The subjects in the first two experiments were 16 adult retardates (mean CA = 20.8 years, mean MA = 5.6 years). The third experiment required a fresh sample of 16 more subjects, similar in chronological and mental age. A crossover design was used in all three experiments. Eight subjects learned a homogeneous series first, followed by a series in which certain items were isolated; the remaining eight subjects learned the two series in the reverse order. All items in each series were shown successively on a screen with a projector. Presentation time was 2 seconds per item with a 5-second interitem interval and an intertrial interval of 8 seconds. Four trials a day were given and learning was completed when the subjects reached a criterion of three consecutive errorless reproductions. The materials in the first experiment consisted of 16 pictures (divided into two series) of common objects. The eight items of Series 1 were: tie, clown, purse, jacket, bird, flower, clock, and bus. The other eight items for Series 2 were: shoe, flask, safety pin, man, tree, glove, drum, and box. In control series all eight items were black outline drawings; in the experimental series, items 1 , 2 , 3 , 6 , 7 , and 8 were black outline drawings, while items 4 and 5 (man and tree) were fully colored pictures. In the second experiment the eight items for the control series

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were: spoon, jug, duck, scissors, ball, lamp, fish, and umbrella. The other eight items for the experimental series were: brush, house, guitar, ladder, apple, lady, tower, and chair. Whereas in the first experiment the isolated items occupied the fourth and fifth positions, in this experiment, the two isolated items were inserted at the second and seventh positions (i.e., house and tower) in the experimental series. In the third experiment, the eight items for the control series were: shoe, flask, safety pin, jacket, bird, glove, drum, and box. The other eight items for the experimental series were: tie, clown, purse, train, cow, flower, clock, and bus. The fourth and fifth items in this series (i.e., train and cow) were isolated simply by being drawn in red outline instead of black outline. Three separate analyses of variance revealed that subjects took significantly fewer trials for the experimental series to reach criterion in the first two experiments (p < .001 and < .01 respectively). In the third experiment, however, there was no significant difference in learning trials between the series. No practice effect was observed in any case. Mean numbers of trials to reach the criterion were as follows: first experiment-1 8.38 (control series), 9.19 (experimental series); second experiment-1 6.16 (control series), 12.25 (experimental series); and third experiment-20.25 (control series), 18.75 (experimental series). Error analysis indicated that subjects made significantly fewer errors in every case where the item was isolated (compared with the equivalent position in the control series). This effect was greatest when fully colored pictures occupied a central position (items 4 and 5). Furthermore, in the first experiment, the adjacent items (3 and 6) were also learned better. Thus these experiments showed that the effect of the fully colored items placed in the middle of the list resulted in a very significant reduction in errors for those items (p < .01) and also in total learning trials to reach criterion (p < .001). By contrast, similar colored pictures placed peripherally resulted in a less significant reduction in errors (p < .05) in the same subjects and a less significant effect on overall learning (p < .Ol); colored outline drawings placed centrally produced a small but significant reduction in errors (p < .05) for those pictures, but no significant overall effect on trials-tocriterion. The effect on trials-to-criterion thus appeared to be associated with fully colored pictures. These results suggest that the amount of isolation effect is a function of the nature of the isolated items. C. Factors Affecting Distractibility

The most frequently remarked aspect of the behavior of retarded people is their distractibility, and comments on this will normally be found in reports by physicians and teachers. But the view that the mentally retarded are always more distractible is not entirely supported by the experimental evidence (e.g., Baumeister & Ellis, 1963; Girardeau & Ellis, 1964). Few

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attempts have been made to study systematically distractibility in retardates with reference to the interaction between type of distractor and nature of the task. On the basis of the result of an experiment (A. Sen, 1966), Sen and Clarke (1968b) aimed to investigate the interaction of tasks and different kinds of potentially distracting extraneous stimuli. Two picture-naming tasks (one difficult, the other easy) were chosen, and five interlinked experiments were reported. The first experiment aimed to study the effect of meaningful-relevant and meaningful-irrelevant auditory distraction on a difficult picture-naming task. A group of 16 retarded adults (mean CA = 22.4 years, mean MA = 6.6 years) was selected for this purpose. The stimulus material consisted of 16 outline pictures of animals. For the meaningfulrelevant distraction condition, the names of the same animals were recorded as a random series by a female voice repeatedly and in rapid succession on a magnetic tape. For the meaningful-irrelevant distraction condition, a list of 16 common objects was similarly recorded. The stimulus materials were mounted on a single sheet of cardboard (20" X 20") with 16 positions so that the pictures (4" X 4") are visible to the subjects in four rows and four columns. The subjects were required to name each of the pictures in turn as the experimenter pointed to them. Eight trials were given during one session. On the first and last trials, no distraction stimuli were presented. The intervening six trials were divided into two parts: Trials 2-4 where meahgful-relevant distraction was applied, and Trials 5-7 where meaningful-irrelevant distraction w a s administered. The results showed that the mean scores under the two distraction conditions differed significantly (p < .01) from that of the first trial (normal condition), though the distraction conditions did not differ significantly between themselves. The mean score for the last trial (second normal trial) following distraction trials was significantly lower than the first normal trial (p < .05), suggesting an aftereffect of distraction. Further analysis by dividing the subjects into two groups, with MA above 7.5 years and below 7.5 years suggested that lower intelligence is associated with high distractibility in a picture-naming task. The high MA group was only distracted under meaningful-relevant condition; moreover, the degree of distraction shown in this condition was also much less than that in the low MA group, which was, however, equally highly distracted under both relevant and irrelevant conditions. At this stage two questions were raised by the investigators: Was the greater distractibility demonstrated by the low MA subjects due (1)specifically to the meaningful nature of the extraneous stimuli, or (2) to the difficulty level of the task? The second experiment was designed to determine whether meaningful extraneous stimuli would impair performance more than meaningless verbal stimuli or other background distraction. Ten subjects with low MA (below

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7.5 years) were used for the same picture-naming task, and three distraction conditions, viz., meaningless distraction, workshop noise at varying levels of intensity (66-88 dB) and a simple recorded conversation between a male and a female voice were applied. Analysis was carried out with the data, including those from the preceding experiment for the low M A group. The mean scores of subjects under different conditions were: normal 8.60, noise 6.93, conversation 6.50, meaningless distraction 4.37, meaningful irrelevant 3.87. The analysis showed that mean scores during noise and conversation, though lower, were not significantly different from that during the normal condition. The mean scores under the remaining three distraction conditions, each using discrete words, differed significantly from the normal condition, but did not differ significantly among themselves. Thus from the results of these two experiments it appeared that discrete words, irrespective of their nature, presented in a word-for-picture correspondence, produced considerable interference with regular responding. The third experiment was designed to clarify the issue of whether the difficulty level of the task was a contributing factor to the distractibility of the low M A group of subjects. Therefore, in this experiment, the authors used a comparatively easy task situation under those distractors which had already shown to be disruptive. Nine adult subjects with low M A (below 7.5 years) were selected for this experiment. The stimuli consisted of 16 outline pictures of common objects (ball, bus, scissors, baby, cycle, bucket, clock, shirt, fish, apple, brush, chair, iron, umbrella, spoon, and shoe) to be named by the subjects under three distraction conditions. A day before starting the experiment, each subject was shown all the stimulus pictures, and all could easily name them. The mean scores under different conditions were 16.00 (normal condition); 15.67 (meaningful-relevant); 15.89 (meaningful-irrelevant); and 15.67 (meaningless). This result showed that extraneous stimuli, which in a difficult situation had proved distracting, had no detrimental effect upon an analogous task which was much easier. Before finally concluding that there is a clear relation between task difficulty and reduced performance in the presence of certain distractors, the investigators carried out two further experiments with subjects of higher ability. Two tasks were employed in the presence of similar distracting stimuli: verbal free recall (easy) and verbal serial recall (difficult) of pictures. Ten adult subjects (mean CA = 23.5 years, mean M A = 9.7 years) were subjected to five different conditions under free-recall situation, employing a 5 X 5 Graeco-Latin square design with two independent replications. A set of 40 pictures of common objects were used, these being divided into five equivalent sets of eight pictures. A list of 16 common words were randomly recorded for use as distractors. The mean scores of the subjects under different conditions were 6.0 (normal), 5.7 (meaningful distraction during presentation of the stimuli), 5.3 (meaningful distraction during response of the

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subjects), 5.0 (meaningless distraction during presentation of the stimuli), and 4.8 (meaningless distraction during response of the subject). The analysis did not show any significant distraction effect in this experiment, and did show that the task was very easy for this group of subjects. Therefore, another experiment was designed to manipulate the variable of task difficulty. This required the subjects to recall eight pictures serially by a serial anticipation method. Thus the investigators raised the difficulty level of the task by manipulating the nature of the responses demanded. Twenty-seven adults (mean CA = 24.5 years, mean MA = 9 years) were used under three conditions, viz., normal condition, meaningfuldistraction and meaningless-distractioncondition. The three sets of pictures were randomly assigned to the three conditions. The exposure time per picture was 1 second with an interitem blank interval of 5 seconds during which the subjects had to guess the next picture. The intertrial interval was 10 seconds. A Condition X Trial X Subjects design was used where the subjects were given the tasks under different conditions in four consecutive trials. The results showed a significant difference between conditions (p < .001) as well as between trials @I < .001). The Subject X Condition interaction (p < .001) and the Subject X Trials interaction @I < .05) were also significant. The significant difference in performance of subjects with relatively high MAS is affected when the task situation becomes difficult for them, though they remain largely unaffected in an easier situation under similar kinds of distraction. Thus from the results of these five connected experiments the investigators concluded that: (1) subjects’ susceptibility to extraneous stimuli designed to act as distractors is related to the level of task difficulty, and (2) not all such external stimuli operate as hstractors for a given task. In another study mentioned earlier, Sen and Clarke (1968a) tested the hypothesis that during learning of a task subjects should be susceptible to distractors, but they should become resistant to these once the task is thoroughly learned. Eighteen adult retardates were selected on the basis of CA, MA, and learning ability determined by cumulative score on four trials. They were divided in two equal groups of nine subjects each, matched on these variables. The mean CA and mean MA for the control group was 25.5 years and 9.2 years, and that for the experimental group was 23.5 years and 9.1 years, respectively. The stimuli consisted of black outline drawings of eight common objects (snake, jacket, keys, saw, gun, train, leaf, and bird). The control group was required to learn the list of pictures to a criterion of three consecutive errorless reproductions under normal conditions, while the experimental group learned the same list to the same criterion of mastery in a distraction condition. Distraction consisted of presenting through earphones 16 common words (flower, lady, bridge, ladder, window, scissors, baby, shoe, table, knife, chicken, box, glove, lamp, pig, and car), which had been recorded repeatedly. The serial-anticipation method was used and the stimuli (4 inches square) were

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projected on a screen. Presentation time was 1 second per picture, with a 5-second interitem interval and an intertrial interval of 10 seconds. The mean numbers of trials required by the control group and the experimental group were 18.56 and 35.66; the difference was highly significant 0, < .005). Further analysis revealed that there was a relation between task difficulty and susceptibility to distraction. The authors also found that once the task was adequately learned and slightly overlearned, the same distractors were ineffective. A single retention trial after a month also revealed no difference between control and experimental groups. These experiments thus indicated that so far as verbal tasks were concerned, there was a consistent relationship between level of task difficulty and susceptibility to influence of certain distracting extraneous stimuli. Since it may be argued that for subjects of this low intellectual level, verbal tasks were particularly susceptible to distraction effects, in another series of experiments A. Sen and A. K. Sen (1968,1971) studied the relationship of task difficulty and distractibility using similar extraneous stimuli in conjunction with nonverbal tasks. The investigators (A. Sen & A. K. Sen, 1968) observed that in a perceptual motor task, the performance of the subjects was not impaired in the presence of extraneous stimuli. A group of 14 low MA retardates (mean CA = 23 years, mean MA = 5.3 years) was selected. The task involved perceptual motor discrimination, requiring the subjects to sort 35 plastic typewriter keytops taken from Clarke and Cooper’s (1964) test materials. There were seven sets of five keys, each set bearing the same symbol. Seven tin boxes, 2 inches in diameter and 3 inches deep, were kept in front of the subject, and behind each key, bearing one of the symbols, was mounted. The 35 keys had to be correctly sorted into the seven leveled tins. The sources of distraction consisted of a tape recording of a story from a children’s book presented over earphones. All subjects were given the task twice, once under normal condition and again under distraction condition after an interval of 15 days. The mean scores under these two conditions were 27.57 and 27.71, respectively, showing no detrimental effect of distraction. Under normal condition the mean score was quite high (about 80%) and, thus due to easiness of the task, the subjects’ performance was not impaired under the distraction condition. On the contrary, under the distraction condition, the speed of the subject increased significantly (p < .001). The mean time required by the subjects under normal condition was 408.5 seconds and that for distraction condition was 308.4 seconds. In another experiment (A. Sen & A. K. Sen, 1971) nine retarded adults (mean CA = 21 years, mean MA = 5.6 years) were chosen on the basis of weighted scores on the WAIS block design test (mean score = 2.22). The task consisted of six geometrical shapes (circle, triangle, square, convex, concave, and piano-concave) repeated randomly in an array of 24 rows, each row containing 18 shapes. There were five conditions where the subjects’ task was to cross out the triangles (there were 73

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triangles and 359 redundant stimuli). The conditions were (1) normal condition, (2) workshop noise (66-88 dB), (3) conversation, (4) meaningful words, and (5) nonmeaningful words. The first three conditions were applied following a randomized block design, while the last two were given after an interval of 2 weeks following the crossover procedure. The results showed that the mean percent scores were quire high under all conditions, being 80.37%, 79.15%, 81.89%, 90.41%, and 89.04%, respectively. Thus the cancellation task used in this experiment did not show any impairment under any of these distraction conditions, suggesting that the task was fairly easy for this group of subjects. In the next experiment in this series, another group of nine naive subjects (mean CA = 24 years, mean MA = 4.8 years) was taken and the same task was administered under two distraction conditions, viz., a recorded story and conversation. This experiment was designed to check the frndings of the previous experiment. The mean percentage score was quite high again under all conditions, viz., normal 75.64%, story 77.93%, and conversation 80.52%. The results of these two experiments together led the investigators to conclude that an easy cancellation task remains virtually unaffected under a variety of extraneous stimuli. Therefore, in this series, another experiment was designed to test the proposition that by raising the level of difficulty of a cancellation task and using the same extraneous stimuli as before, performance would be affected. Twenty subjects (mean CA = 22 years, mean MA = 5.8 years) were selected, the mean weighted score on the WAIS block design test of the group was 2.90. A more difficult version of the cancellation task was devised. Six outline geometric shapes (same as used earlier) were drawn in pairs of different combinations, producing thereby some identical and some nonidentical pairs. There were altogether eight columns, each column containing 25 pairs, among which there were 30 identical pairs randomly distributed over the columns. The distraction stimulus was the tape recording of a story presented over the earphones. The results showed that under the distraction condition, subjects took significantly less time (p < .001), significantly increased their scores (p < .Ol), and made significantly more errors (p < .02). The results at first glance thus appear to be ambiguous. An inspection of the data showed that the subjects who worked under the distraction condition attempted more items, got more items right and also more items incorrect than the subjects who worked under normal conditions. A post hoc inspection further suggested that the subjects who had poor scores during the normal condition made relatively more errors during the distraction condition than those who had initially rather better scores. The significant correlation (r = .54, p < .01) between error difference and WAIS score indicated that distractibility is associated with nonverbal intelligence for this type of task. Further analysis was done by ranking all the 20 subjects on the basis of their original scores obtained during normal conditions and then dividing them into two groups-high scorers and low scorers, respectively. The analysis

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showed that the low scorers made significantly more errors (p < .025), significantly more scores (p < .05),and had a significant reduction in time (p < .Ol), while the high scorers did not show any significant change in any of these measures. This analysis shed light on the apparent ambiguity of the findings mentioned earlier. It was assumed that these low scorers went on carelessly crossing out more items and thus taking less time during the distraction condition. The result of this experiment thus indicated that the subjects to whom the task was comparatively more difficult made significantly more errors in the distraction condition than those to whom the task was easier. These fmdings again suggested a relationship between task difficulty and susceptibility to extraneous stimulation. However, the studies taken in conjunction with evidence from other studies suggest that factors hke the nature of task, its duration, the intensity of distraction stimuli, the relevance of the distractors to the task, etc., are also important in determining a subject’s susceptibility to distraction. The findings of these experiments offer evidence that blanket descriptions of the mentally retarded as “distractible” cannot be made justifiable without specifying the precise conditions under which this is exhibited or whether it can be overcome by learning. D. Other Studies 1. SIGNAL DETECTION

Das and Bower (1971) carried out an experiment on orienting responses to word signals. Twenty-five retardates (IQ range 40-65; CA range 13-16 years) and 25 normal children (mean IQ = 119; CA range 13-14 years) were subjected to a 30-minute vigdance task which consisted of six familiar words (box, man, cat, door, key, and bell) presented by a tape recorder. The subjects had to detect the occurrence of the signal word “man” (imperative signal). This signal always followed the word “box” (warning signal). The sequence box-man occurred once during each minute for a total of 30 times throughout the experiment. Intervals of 10 seconds separated the words. The position of the six words was randomly determined for each 1-minute period, with the exception that “man” always followed “box” and no word followed itself. GSR records were taken during experimentation and the results showed that the “warning signal” evoked a greater number of GSRs in the normals than the “imperative one”; this was reversed for the retardates. GSR adaptation to signal words occurred at the same rate and level for both groups; but in adaptation to the nonsignal words, the retardates maintained a higher level of GSR frequencies than the normals. In a further study (Bower & Das, 1972), the researchers investigated acquisition, reversal, adaptation, and inhibition of the orienting response in another group of educable mental retardates (mean CA = 14 years; mean MA = 12.3 years) and its CA and MA matched normal groups. There were

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27 subjects in each group and GSR frequency, magnitude, and latency were used as indices of orienting response. The results indicated that the retarded subjects maintained and modified the orienting responses as effectively as the normals during acquisition and reversal. 2. INTELLIGENCE AND PERSONALITY TESTING

The intelligence tests meant to determine the IQ of the retardates are not always standardized instruments for application in India. Earlier, most of the time either the Form Board or Stanford-Binet test were used. Recently Malin (1968) has revised Wechsler’s Intelligence Scale for Children (WISC) under Indian conditions and renamed the test as Intelligence Scale for Indian Children (ISIC). Psychologists administer this test to the new entrants following a medical check-up by the physician. Malin (1969) also made a comparative study of performance on WISC by 713 mentally retarded American children (IQ 46-75) and 106 retarded children from India (IQ 40-80). While the mean MAS for both the groups were similar (6.5 years for American; 6.2 years for Indian), the SDs were quite different (2.16 for American, 4.01 for Indian). The American sample did better on performance than verbal tasks, while the Indian children performed better on verbal tasks. The subtests in which the children were most similar were similarities and block design, while the most differences were found in the picture completion and object assembly tasks (on which the Indian group performed most poorly), and vocabulary, information, and comprehension (on which the American group performed most poorly). A. K. Sen and Sen (1969~) examined the relationship between intelligence and speed of learning. A correlation between MA and trials to criterion turned out to be -0.54 (p < .01) within a group of retardates (MA range = 5-10 years). Prasad and Pershad (1973) found a correlation between intelligence and memory span for digits (both forward and backward) to be 0.61 (p < .01) within a group of 167 retarded children (CA range = 5-15 years). b u r and Sen (1974), in a study, did not find any significant relationship between intelligence and socioeconomic status (SES) in a group of 87 institutionalized mentally retarded children; though other studies had shown the higher incidence of mental retardation is prevalent in low SES groups (Jachuck dc Mohanti, 1974; Kuppuswami, 1968). Verma, Pershad, and Kaushal(l972) applied the Gesell Drawing test, the Seguin Form Board test, and the Vineland Social Maturity Scale (Indian adaptation) upon a group of 54 mentally retarded children (CA range 5-15 years). On the basis of the results, the authors suggested that the Gesell Drawing test can be used as a test of intelligence on the mentally retarded children. Teja, Shah, and Verma (1970) administered the Seguin Form Board Test, the Poreus Maize test, Raven’s Colored Progressive Matrices, and the Draw-A-Man test upon a group of 133 mental retardates. They found a high correlation between delayed motor milestones (Gesell, 1949) and impairment of social functioning. In the mildly

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retarded subjects, there was a negative correlation between impaired motor milestones and measured IQ and social functioning. V. Mohan and Sethi (1968) compared 25 male (modal CA = 14.1 years) and 25 female (modal CA = 14.3 years) retardates with two different groups of normal children on neuroticism and extroversion scores. Based on Eysenck's (1 960) findings, the authors hypothesized that retardates would be more extroverted and less neurotic. The Junior Personality Inventory (V. Mohan, Singh, and Kalra, 1968) was administered individually to all the subjects. The hypothesis that retardates are comparatively more extroverted than normals was accepted (p < .01). There was no sex difference in either group on extroversion scores. The authors could not make such comparisons for neuroticism scores because of the non-normality of the distribution. However, by and large, scores for retardates did not appear to be significantly different from those of normals. Measures of central tendency revealed that retarded girls tended to be significantly higher on neuroticism scores than boys. Shukla and Khoche (1974) administered Bell's Adjustment Inventory (Hindi version) upon 50 mental retardates (mean IQ = 66) and 50 normals (mean IQ = 97), age range 12-18 years. Results showed that retardates have more adjustment problems than normal adolescents. Overall adjustment score for retardates was mean = 70.82, SD = 9.60, and for normals, mean = 46.66, SD = 3.52. The difference was highly significant 0,< .01). Mazumdar, Prabhu, and Neki (1971) studied the behavior of three groups of retarded children (CA = 11-12 years, IQ = 51-70), 20 in each group, under three different environmental conditions. They found that the group who lived in the hostel attached to the school benefited most, while the children who were attached as day scholars benefited to a slightly lesser extent, and those who remained in the school as permanent residents benefited least. The authors concluded that traditionally prescribed atmosphere of the day scholars might not work out to be ideal in the Indian society. Banerji (1970) studied the nature of relationship patterns of several pairs of retarded children through the sociogram. The result showed positive emotionally structure pairships reflecting social and physical pattern of the retardates. Gandhi (1974) in an experiment demonstrated that through the use of social feedback technique, it is possible to teach the retardates a variety of social behavior. J. Mohan and Menon (1968) studied the relationship between persistence on a physical task and intelligence in two groups of boys. Thirty-two mildly retarded subjects (mean CA = 13.7 years, mean MA= 12 years) and 32 normals were given a test of physical persistence with a hand dynamometer. The preferred hand was used to obtain a setting of each subject on three trials. A measure of persistence was provided by instructing the subject to keep the pointer of the dynamometer steady at that point for as long as he could. No significant difference between normals and retardates was found. In another

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study, J. Mohan and Menon (1969) studied the relationship between physical persistence and personality factors as measured by Junior Personality Inventory in a group of 64 subjects. A 2 X 2 X 2 design revealed that only extroversion is significantly related to physical persistence (p < .05), and that retardates do not differ from normals. To clarify the question of intelligence in relation to physical persistence, J. Mohan (1972) carried out two experiments taking retarded, normal, and gifted children as subjects. The first experiment attempted to compare the performance of the normals with that of retardates on persistence scores. In the second experiment the performance of the normals was compared with that of gifted children. On the basis of the results, the author suggested a U-shaped relationship between intelligence and persistence. Das (1972) reported a study where he found that a cross-modal task has a high factor loading on a progressive matrices factor when normal children are used as subjects. Panda and Lynch (1973) administered Intellectual Achievement Responsibility (IAR) Scale (Crandall, Katkovsky, & Crandall 1965) and Kagan’s Matching Familiar Figure test (Kagan, Moss, & Siegel, 1963) upon a group of 85 educable mentally retarded children. They did not find any significant relationship between these two tests in this group of retarded subjects. In a subsequent study the investigators (Panda & Lynch, 1974) applied IAR within a group of 249 children. Results showed that educable mental retardates have greater belief in luck in failure situations as compared to success situations. A few investigators studied the behavior of the parents of mental retardates. Pershad, Kaushal, and Verma (1973) observed that the mothers of the retarded children were comparatively more neurotic than the mothers of normal children. Prabhu (1970) found that parents who overestimated the potentialities of their mentally retarded child were more extroverted (p < .02) and emotionally unstable (p < .01) than parents who were able to evaluate their children in a realistic manner. Srivastava (1970) in his study did not find any relationship between incidence of mental retardation and age difference of the parents. 3. MEASUREMENT OF MEANING

Semantic differential originally developed by Osgood, Suci, and Tannenbaum (1957) is a standard method of measurement of meaning. In this method the subject is asked to differentiate an item on bipolar adjective scales which

represent some major factors of connotative meaning. Using this technique Agrawal and Gandhi (1968) made a comparative study of graphic and verbal scales in the measurement of affective meaning among a group of 20 institutionalized moderately retarded children (IQ range 40-74, mean IQ = 54). Eight graphic and eight verbal %point semantic differential scales were constructed for eight separate concepts: teacher, banana, mummy, pencil, bread, dog, flower, and home. All the 16 scales were administered to each subject for each concept.

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No significant difference between mean graphic and mean verbal scale scores was found for the eight concepts, nor for deviations for the neutral scale point (position 4) for the two conditions over eight concepts. The hypothesis that mental retardates have relatively greater ability to use pictorial rather than verbal symbols was questioned by authors. In another study Jachuck, Dattar, and Das (1968) studied the effect of age and stimulus meaningfulness on semantic satiation in a group of nonretarded subjects. They observed higher satiation scores among adults than children. The authors discussed the implication of their result from a developmental point of view. If one regards the mentally retarded subject as equivalent to his MA matched counterpart, the result of this experiment indicated that an adult retarded will show greater resistence to satiation than a normal adult. Therefore, it implies that in teaching a retarded person, repetition of verbal symbols should not provoke inattention. However, for the evaluation purpose the semantic differential method is not a suitable technique for the low-grade retardates. 4. PERCEPTUAL SKILL

N. P. S i g h (1974) reported a study in the area of perceptual skill. In one experiment a group of 30 retardates (mean CA = 1 1.5 years, mean MA = 6 years) were matched with 30 nursery school children of equal MA. Using a Galton bar, the subjects were required to adjust linear extents at different levels, viz. 50 mm, 100 mm, and 200 mm. Normal children performed the task better than the retardates in all conditions J( < .001). However, the results indicated that both the groups’ performance was best at 100 mm extent and worst at 50 mm. Errors were minimum during outward movement, and performance of both the groups was better when the standard was kept on the right-hand side of the subjects. The Weber ratio for the normal children was .07 and that for the retarded group was .13; the difference was significant (p < .05). In the second experiment a naive group of 12 mental retardates (mean MA = 6.5 years) were taken. In a 4 X 3 design, they were required to set the stimulus at “half,” “equal,” and “double” the standard of 100 mm extent, under four different conditions. The analysis showed the “knowledge of result” produced better performance for this group of subjects. The other conditions in order of preference were “no instruction,” “avoiding error,” and “restricted movement.” The results further indicated that the subjects made minimum errors when they were required to set the stimulus “equal” to the standard. Maximum errors were committed when they tried to estimate “half.” S. B. Singh and Virmani (1 970) also studied perceptual skill in various grades of retardates. By applying Bender Gestalt and Draw-a-Person tests, they were able to differentiate primary and secondary mental retardates on various perceptual parameters. Shah, Verma, and Taja (1970) in a study observed poorer motor development in the primary group.

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164 111. AN OVERVIEW

The Indian society is keen to see that even its most humble member, with severe shortcomings, finds a place in it, though in a meager way, without living an unduly parasitic life. In this context, scientific enquiry is of utmost impor. tance to highlight the abilities and limitations of those less fortunate inhabitants. When the size of the country and diversity of population with numerous languages and religions are taken into consideration, mental retardation research is a very promising field in India. Das (1968a) has mentioned that caste is an important modifier of cultural deprivation. In this context, it could be mentioned that one of the most striking features of ancient Indian sociology was the hierarchy of classes. There were four classes, viz., Brahmin, Ksatriya, Vaisya, and Sudra, who were separated by birth for generations. When the Portuguese came to India in the 16th Century, they called these classes castes, meaning tribes, clans, or families. The name stuck and became the usual word for Indian social group. The duty of the Brahmin, the highest caste, was to study and teach, and to sacrifice. The duty of the Ksatriya was “protection,” which included fighting in war and governing in peace. The Ksatriyas claimed and received certain privileges. The Vaisya was the mercantile class, whose chief functions were to breed cattle, pursue trade, and lend money. The ideal Vaisya had expert knowledge of jewels, metals, cloth, threads, spices, perfumes, ar.: all manner of merchandise. The Sudras, the humblest of the four classe., ’-;ere in fact second-class citizens, on the fringe of the society, and their duty was only to serve the three higher classes. The Sudras were called untouchables, depressed classes, or schedules castes; now they are known as Harijan, meaning God’s own people. Relations between classes and social groups were governed by rules of endogamy (marriage was only legitimate within castes), commensality (food was only to be received from and eaten in the presence of members of the same or a higher class), and craft exclusiveness (each man has to live by the trade or profession of his own group and not take up that of another). The caste provided social security, helping destitute members and caring for widows and orphans. Castes rose and fell in the Indian social scale, old castes died out and new ones were formed, but the four great classes were stable. They were never more nor less than four, and for over 2000 years their order of precedence has not altered. There appear to be striking similarities between caste barriers in India and racial discrimination in the United States. Both no longer exist legally, yet socially the deeply imbedded attitudes cannot be easily erased by simple edict. Das et al. (1970) observed that cultural and psychological differences still attach weight to India’s four different castes, namely Brahmin (priests and teachers), Ksatriya (ruler and warrior), Vaisya (businessman), and Sudra (serf). They found that the subculture to which a child belongs at birth is a major

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determinant of his competence. Indian society developed a very complex social structure, arising partly from tribal affiliations and partly created by successive waves of immigration from various parts of the world, namely Asia, Africa, and Europe (Portugal) from time immemorial. Though marriage across caste lines is easier now than in the past, such a union can still pose problems in families where the tug of tradition is strong. The normal religious marriage is still arranged by the parents of the couple, after consultation and the study of omens, horoscopes, and auspicious physical characteristics. The couple should belong to the same class or caste. The rule was very strict in northern India where marriages were forbidden between persons with a common paternal ancester within seven generations or a maternal ancester within five. In the south, however, this rule was not followed and there are records of cousin marriages even in higher castes. Very recently the caste system has shown real signs of breaking down, and the social stigma created by various ethnic groups has started melting in the country’s “melting pot.” Just as the society was divided into four classes, so the life of the individual was divided into four stages, having four central desires. Pleasure is the first desire. It is predominant in infancy, but remains throughout later ages. At the second stage, the desire for pleasure is supplemented by the need for success in the form of power, status, leadership, and masculinity. Youth and middle ages are spent in the pursuit of these. In the third stage of life the ethics of social living take hold upon one’s values. At this stage there is normally a strong orientation toward duty toward aging parents and offspring. The final stage is the religious desire, where liberation from the pleasuresuccess-duty stages of life is longed for. To some extent, these stages correspond to earlier and later periods of life. According to Allport (1961) no major Western school of psychology included this whole sequence of four stages within the view of human nature. Positivist psychology gave full attention to the first two stagesto pleasure, in its theories of reinforcement, libido, and needs, and to success, in its studies of leadership, power, and achievement. Existentialism, on the other hand, gave full recognition to duty but said little about pleasure and success as motives. Thus according to Allport (1961) “this Hindu formation of the essential nature of man is more synoptic and complete than any one school of western thought.” Research in mental retardation is a very promising field in India, when social, cultural, nutritional, and philosophical aspects are explored. According to Hurley (1969), culturally deprived chldren in any community comprise the majority of the retarded. In Western countries, cultural deprivation is noticed predominantly in low socioeconomic groups. But in India, caste also appears to be an important factor in addition to economic status. In rural India, caste and socioeconomic status would go together, but in highly bureaucratic and urban society, education, occupation, and income are indicators of socioeconomic

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status, each of these factors determining the other (Srinivas, 1962). Because of the society’s failure to provide a suitable human environment for all of its citizens, the culturally deprived children have a much greater chance of becoming mentally retarded, juvenile deliquents, or criminals. Until the whole structure of “environmental deprivation,” i.e., a structure which includes prejudice and discrimination, poor nutrition, inadequate health services, substandard housing, inferior education, unemployment, etc., is destroyed, no spectacular breakthrough can be made in the problem of mental retardation. Research, in fact, can only reveal the obvious causes of mental retardation but it can not ameliorate the conditions as long as environmental deprivation and poverty exist. As a field of scientific enquiry, mental retardation has received attention only recently in India; and a host of interdisciplines such as neurology, biochemistry, genetics, physiology, sociology, education, nutrition, psychology, and psychiatry have to take an appropriate role in it. It is hoped that individuals of widely varying vocations will share a vital interest in this field. Work in this area is not only rewarding for its immediate theoretical interest, or practical implications for the retarded person, but also for its bearing upon the study of mankind. Many of the developments in education of the normal children have come as a result of research regarding the identification and training of the mentally retarded children. Therefore, research done in this field will not only be confined to the problem of the mental retardates, but will be applicable to the larger number of average children as well. India is the most crowded country in the world; 13 million babies are born every year to the present 550 million population. The present retarded population in India could be anywhere between 15 and 22 million (A. K. Sen, 1975), and about 400,000 retardates are being added every year. The implications of research into cultural deprivation have a national significance. In addition to the 3 4 % mentally retarded persons in India, a large percentage of people are dull or slightly backward, their IQs falling between 70 and 90. It is mainly this group which contains a large number of culturally deprived persons. This immense problem is in urgent need of effective attention at the national level. With a new awareness of the nature of the society and of the deprivation inherent in the environment, a more valid and humane appreciation of mental retardation will be possible. The ultimate aim of research in this field will be the elimination of mental retardation caused by social, economic, and cultural factors.

IV. CONCLUSION

The question is often raised that since there is a problem of unemployment in India, and adequate vocational facilities are not available for normal youth, why employ mental retardates, and why make the facilities for vocational and

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institutional training available to them? However, it has been recognized now that the rehabilitation of retardates does not have to wait until problems concerning the employment and habilitation of normal individuals have been solved. Before 1960 there were only 22 institutions in the whole country, and mental deficiency as a topic aroused very little research interest among physicians and psychologists. Between 1961 and 1965,23 more institutions came into being, and a few scattered studies were available in the literature. To date, there are 91 known institutions in India, and the last decade has witnessed more than 50 experimental research publications in this area. However, an average of five publications per year all over the country, though a sign of healthy growth, is far from adequate. Many factors have been responsible for the lack of progress in this field. In the past there has been a lack of interest in professional circles. The language problem restricts the application and standardization of psychological tests over large samples, making the available norms unreliable (Prabhu, 1969). Research has also been limited since priority was given to the development of educational facilities for normal children. Another hindrance to the growth of this field is that psychologists in India have a marked propensity to change their research interest before a particular field is properly developed. Quite a few psychologists whose works have been mentioned in this review have shifted their research interest into another field. With 35 university departments and with a doctorate group of over 400 psychologists (1974) in the country, an average output of five papers per year in the field of mental retardation is woefully low. Again, research done in this area has been so scattered and so ad hoc that there has been little accumulation of knowledge in the field. Formation of research groups also is proceeding more slowly than is desirable. However, India has quite a few specialists dedicated to the welfare of the mentally retarded. The Federation for the Welfare of the Mentally Retarded (India) is a voluntary organization with a special technical cell of psychologists and other specialists to coordinate and promote research in this field. Several universities are offering courses of study in mental retardation. Therefore, further initiative must be taken by all the individuals and institutions who are devoted to this field. It is now clear that much can be done to use, develop, and indeed sometimes to create limited assets in retardates, in a way thought impossible 10 or 15 years ago. It must be realized that the experiments reported herein were confined mainly to the research laboratory. In the research laboratory the studies are microscopic in nature, but they should be considered as basic data which could be extended and evaluated further in a practical situation. Of course, the generalization emanating from the research study may not be directly applicable to the learning in a classroom situation. The dynamics operating in the former and those operating in the latter are not directly comparable. Nevertheless, when similar studies are done in India, educators will have more psychological information in their planning for the education of

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retardates. Though there are gaps and loose ends in the experiments conducted by the investigators, problems raised by these findings certainly suggest fruitful areas for further research. The fund of information reported herein is incomplete and fragmentary; as such it is expected that further research will record more, indicating in depth the detail of abilities, disabilities, and learning potential in mental retardates.

ACKNOWLEDGMENTS

This chapter was written while the author was a visiting Fulbright-Hays scholar in the Department of Psychology, University of Alabama. The preparation of the chapter was supported by the United States Government grant from the Council for International Exchange of Scholars, Washington, D.C. The author wishes to express his gratitude to Professor N. R. Ellis, who read the manuscript critically and made many valuable comments and suggestions. The author also owes thanks to Dr. Anima Sen, who helped in many ways.

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Stroop, J. R. Studies of interference in serial verbal reactions. Journal of Experimental Psychology, 1935,18,643-661. Teja, J. S., Shah, D. K., & Verma, S. K. A comparative study of motor and social milestones and their relationship with intelligence test results in the mentally retarded. Indian Journnl of Mental Retardation, 1970,3,75-79. Verma, S. K., Pershad, D., & Kaushal, P. &sell's drawing tests as a measure of intelligence in the mentally retarded children. Indian Journal of Mental Retardation, 1972, 5 , 6 4 4 8 . Von Restroff, H. Ober die Workung von Bereichsbildung im Spurenfeld. Psychologie Forschung, 1933, 18, 299-342. Cited by Koffka,K. hinciples of Gestalt psychology. New York: Harcourt, 1935.

The Conditioning of Skeletal and Autonomic Responses: Normal-Retardate Stimulus Trace Differenced SUSAN M. ROSS AND LEONARD E. ROSS UNIVERSITY OF WISCONSIN, MADISON, WISCONSIN

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I. Introduction 11. Retardation and the Stimulus Trace Concept 111. Stimulus Trace Decay in Classical Conditioning: Background N. MethodologicalConsiderations A. The Interstimulus Interval in Eyelid Conditioning B. The Interstimulus Interval and Multiple Responses in Electrodermal Response Conditioning C. Confounding Temporal Variables in Trace Conditioning V. Trace-Delay Conditioning Studies A. Normal Subject Data B. Normal-Retardate Comparisons VI. Summary and Conclusions References

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1. INTRODUCTION

The process analysis approach to the understanding of the general behavioral deficiencies of the retarded has usually taken the form of comparing the performance of normal and retarded subjects in experimental situations which are designed to permit the interpretation of obtained differences, or the lack of them, in terms of the processes of interest. Unfortunately such process analyses Preparation of this paper was made possible by NIH grant HD08240 from the National Institute of Child Health and Human Development.

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have proven slow and difficult to accomplish. As is typical of behavioral research, theoretical and empirical cul-de-sacshave been plentiful, and conflicting data have more often been the rule than the exception. Part of the problem stems from the fact that performance in research situations is often quite sensitive to experimental parameters whose effects are too frequently unrecognized in cross-study comparisons. Similarly, variables and processes other than those of interest may be operating in a particular situation so that interpretation of results obtained from the use of seemingly simple paradigms may be quite difficult. The present chapter examines stimulus trace factors in normal and retarded subjects as investigated through the use of trace and delay classical conditioning procedures. Although those reviewing research on this topic have considered the data to be inconsistent and nonsupportive of the idea of normal-retardate differences in trace conditioning, the conclusions of the present chapter are quite to the contrary. Indeed a close examination of the skeletal and autonomic conditioning literature in the context of certain methodological considerations reveals surprisingly consistent and interesting performance differences on the part of normal and retarded subjects. Since practically all of the studies investigating the trace-delay variable in humans have employed either electrodermal response (EDR)or eyelid conditioning paradigms, only research involving these response measures, autonomic and skeletal respectively, will be considered.

II. RETARDATION AND THE STIMULUS TRACE CONCEPT

The concept of a stimulus trace and its use as an explanatory device in accounts of various behavioral phenomena has a long and continuing history in psychology. From this general background Ellis (1963) proposed a stimulus trace-behavioral inadequacy relationship on the part of the retarded. It was suggested that the lessened central nervous system integrity of the retarded resulted in shorter and less intense stimulus traces with resultant differences between the retarded and normals on behavior tasks dependent upon short-term memory. In his paper Ellis briefly reviewed the stimulus trace concept as it had been evoked from the early 1900s in diverse areas of psychology ranging from theories of retroactive inhibition, classical conditioning, and psychophysical judgment. h addition, evidence from a variety of research areas including investigations of serial position effects, delayed reactions, the EEG, operant behavior, reaction time, and paired-associate learning was examined with respect to the hypothesized stimulus trace-behavioral inadequacy relationship. It was tentatively concluded that many normal-retardate differences could be, at least

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in part, ascribed to immediate and short-term memory deficits, a conclusion that supported the stimulus trace theory. Ellis’ paper provided the impetus for numerous studies designed to examine stimulus trace theory by comparing normal and retarded subjects in situations where a stimulus trace deficit would be expected to adversely affect performance. The results of these studies have been inconclusive. Ellis (1970) commented that evidence for and against the stimulus trace deficit idea could be found in the literature, and Scott and Scott (1968) stated that at times its predictions have been confirmed and at other times not. Estes (1970, p. 115) in his review of Ellis’ theory concluded that tests of the original stimulus trace theory were “encouraging for the idea that a specific short-term memory deficit might characterize the mentally defective, but not for an identification of the deficit specifically with the stimulus-trace concept as developed in Hull’ssystem.” In his own work Ellis turned to short-term memory research and in 1970 published a paper on memory processes in retardates and normals which presented a memory model and an analysis of a series of short-term memory studies which used a serial position memory task. Ellis’ analysis led him to adopt, tentatively, a rehearsal strategy deficiency rather than a trace deficiency to account for the normal-retardate differences found in his memory task. In retrospect it is not surprising that stimulus trace theory failed to be supported consistently by research involving a number of diverse experimental paradigms. Ellis and others have pointed out that the 1963 stimulus trace theory was not intended to be a complete theory of memory. Obviously such a tentative and simple theory could not be expected to account for data from experimental situations that undoubtedly involve many perceptual, memory, and learning processes in various combinations. The translation of such a notion as a stimulus trace into experimental terms in complex situations now appears naive and simplistic given the complexity of both the behavioral processes involved and the memory models necessary to deal with them. Estes (1970), for example, points out how the operation of attentional and rehearsal processes offer alternative explanations of data interpreted as supporting the notion of a retardate stimulus trace deficit. The fact remains, however, that a stimulus trace deficiency on the part of the retarded might well correctly describe a source of normal-retardate differences. The absence of clear-cut data from more complicated situations do not rule out the possibility that the stimulus trace concept, or something similar to it, might be an important factor when examined by experimental paradigms which reduce the degree to which other processes affect the data. One paradigm possessing such characteristics is classical conditioning, which investigates a form of relatively simple learning but without necessarily requiring a “volitional” response, or any active involvement on the part of the subject.

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Trace conditioning is defined as a situation in which the conditioned stimulus

(CS) terminates prior to the onset of the unconditioned stimulus (UCS),while in delay conditioning the CS continues at least until the onset of the UCS. Thus poorer trace conditioning performance presumably reflects a failure of the trace representation of the CS to provide an effective CS substitute for the conditioning process. Perhaps a special and most precise method could be elaborated by means of trace conditioned reflexes. By changing, on the one hand, the duration of the indifferent stimulus, which must be turned into a special trace conditioned stimulus, and, on the other hand, the interval between the end of the indifferent agent and the beginning of the unconditioned stimulus that reinforces it, we shall be able directly to measure the degree of inertness or lability of the given nervous system. It can be anticipated, for instance, that depending on the time needed for the disappearance of the trace of the stimulus which has ceased to act, the above indicated interval will be of essential importance for a quicker or slower elaboration of a trace conditioned reflex, or even for the possibility of its elaboration in general. The duration of the indifferent stimulus will likewise make itself felt. It is conceivable that in a particularly inert nervous system there will be specially and rapidly revealed for this stimulus the minimum duration under which it is still possible to elaborate a trace reflex. [Pavlov, 1935, p. 333.1

As can be seen from the above quotation, the idea of identifying subject characteristics by comparing their performance under varying trace conditions is hardly new, although studies comparing the performance of normal and retarded subjects under trace and delay conditions are quite recent. Following Pavlov’s original description of the trace conditioning paradigm and trace reflexes (Pavlov, 1927), trace conditioning procedures were employed in several studies, but relatively little interest was displayed in comparing trace and delayed conditioning performance. Hilgard (1 940) described earlier studies as finding poorer EDR conditioning performance with trace conditioning, although the comparison he relied upon was rather indirect and the primary interest in these studies was in a comparison of the changes in the latency of responses under the two conditions. One of these studies was by Rodnick (1937), whose paper reported his Ph.D.dissertation done in Hull’s laboratory, and given the interest in trace conditioning it is not surprising that Hull (1943) made rather extensive use of the stimulus trace concept in his book Rinciples of Behavior. In Essentials of Behavior Hull (1951) further elaborated the role of the stimulus trace concept in his theory of behavior, Here, however, he juxtaposed the results of eyelid conditioning studies by Reynolds (1945) and Kimble (1947) and concluded from the trace and delay conditioning data that there did not appear to be much difference between the molar aftereffects of delay and trace stimuli.

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The fact that these skeletal conditioning data presumably conflicted with the EDR results was not noted, nor was the possibility discussed that the interstimulus intervals (ISIs) compared in the Reynolds and Kimble studies were quite short, 400 msec and less, where a trace deficit would be least likely to be found. Little interest was evidenced in further comparisons of trace and delay conditioning procedures until the middle 1960s when such studies again appeared. One group of studies, involving the conditioning of the EDR, derived from an interest in the effects of cognitive factors in conditioning. Presumedly in long-interval trace conditioning the subject would be less likely to discover and cognitively respond to the CS-UCS relationship. Interestingly, one study in t h i s group used retarded subjects in order to reduce the cognitive involvement of subjects in the conditioning situation. The second group of studies, which employed both skeletal and autonomic conditioning, were instigated rather directly by Ellis’s stimulus trace theory and typically compared the trace and delay conditioning performance of retarded and normal populations. The data of these two groups of studies will be analyzed in some detail following a discussion of some methodological considerations in interpreting the results of trace and delay conditioning experiments.

IV. METHODOLOGICAL CONSIDERATIONS

It appears that much of the confusion about a retardate trace conditioning deficit comes about as a result of methodological differences among studies. Often studies comparing normal and retardate conditioning performance have been designed without taking into account variables that are known to have a profound effect on conditioning, and thus considerable differences in experimental outcomes can often be related to differences in procedures and parameter values used. Several important methodological considerations are discussed below. A. The Interstimulus Interval in Eyelid Conditioning

The IS1 has been found to be a potent variable in both the single-cue and differential conditioning of skeletal responses in normal adults, retardates, and animals. For single-cue conditioning it has been a general finding that an IS1 of approximately 500 msec is optimal. Eyelid conditioning has been found at ISIs as short as 350 msec for both normal and retarded subjects, but an IS1 of 250 msec is clearly too short to be effective for eyelid conditioning for both of these groups (S. M. Ross, 1972; S. M. Ross & Ross, 1971). Conditioned eyelid

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responding is also found at ISIs in excess of 500 msec, although conditioned responding by retarded subjects declines as the IS1 approaches 1400 msec (S. M. Ross, 1972). Responding by normal subjects seems to decline at a somewhat slower rate, with conditioned responding still present when the IS1 is 1400 msec. The IS1 function for differential eyelid conditioning is similar to that for singlacue conditioning, but displaced by about 300 msec with an optimal value of 800 msec or more (Hartman & Grant, 1962). This longer optimal IS1 is consistent with the idea that differential responding involves processes in addition to those involved in singlecue conditioning. In particular, it has been argued (L. E. Ross & Nelson, 1973) that singlecue conditioning requires stimulus detection while differential conditioning has an added requirement of stimulus recognition. It is this additional recognition process which is thought to account for the greater time requirement in differential conditioning. Given the importance of IS1 as a variable in eyelid conditioning, studies which are designed to investigate the effects of CS parameters obviously must employ suitable ISIs. For example, an IS1 of 250 msec cannot be used if a particular variable’s effect on the conditioning process is to be investigated, since good conditioning would not be expected with such a short ISI. The IS1 should also not exceed 1400 msec if normal-retardate tracedelay conditioning differences are to be investigated, since a normal-retardate difference in the effect of IS1 itself appears at that point on the IS1 continuum. B. The Interstimulus Interval and Multiple Responses in Electrodermal Response Conditioning

The function relating EDR conditioning and IS1 is much more complicated

than is the case with eyelid conditioning. Difficulty arises because the EDR has a latency of several seconds and because more than one response can occur on any particular trial. When the IS1 is of sufficient length, these various response components, which may reflect different underlying processes, can be separated on the basis of latency. However, when the IS1 is short, less than 5 seconds, the response components overlap and cannot be analyzed separately. For this reason, Badia and Defran (1970) and others have argued that short IS1 and long IS1 EDR conditioning data cannot be meaningfully compared. The response components which are seen on long IS1 EDR conditioning trials have been identified in terms of their latency and the presumed processes underlying their occurrence. Responses which occur within the first few seconds after CS onset have been labeled first-interval responses, and some have suggested that these responses reflect orienting to the onset of the CS. Responses occurring more than 4 or 5 seconds after CS onset but prior to UCS onset have been labeled second-interval responses or conditioned responses (CRs), and a

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response which occurs on trials when the UCS is omitted, as on test trials and extinction trials, has been called an omission response. This response occurs after the point at which the UCS would have been presented had the trial been reinforced, and it has been described as an orienting response arising from the subject’s expectation of the UCS. It should be noted that several nomenclatures for these different response components have been suggested, including a more elaborate recent proposal by Prokasy and Kumpfer (1973). First-interval, second-interval, and omission response labels have been adopted for use in this chapter for simplicity’s sake. It is of particular importance to distinguish among these various response components since the responses have been found to be independent in some cases, and differentially sensitive to the manipulation of stimulus parameters in the conditioning situation as well, which implies that different processes are involved. In addition there is evidence to be described later in the chapter that normal-retardate differences in both trace and delay EDR conditioning occur only in the case of certain components of the multiple response. Finally, since a test trial procedure involving omission of the UCS must be used with ISIs less than the latency of the EDR, and since it is impossible to determine whether such test trial responses are first-interval, second-interval, or omission responses, the interpretation of the results of short IS1 studies is difficult indeed. C. Confounding Temporal Variables;in Trace Conditioning

In the case of trace conditioning two stimulus parameters in addition to IS1 are often manipulated: the duration of the CS and the length of the trace interval measured from CS offset to UCS onset. However, there are only two degrees of freedom in this situation since the selection of trace interval and a CS duration determines the ISI, the selection of an IS1 and a trace interval determines CS duration, and the selection of an IS1 and a CS duration determines the trace interval. A number of investigators have selected a fixed CS duration and varied the trace interval (e.g., Behrens, 1962; Carruthers & Lobb, 1973; Lobb, 1968). As Fig. 1 indicates, these variations in trace interval are confounded with IS1 differences. Thus, for a given CS duration the range of trace intervals which can be examined is limited since each trace interval must, when added to the CS duration, result in an IS1 which is effective for conditioning. If the CS duration and trace interval duration sum to an IS1 which is too short for conditioning, this IS1 effect cannot be interpreted as an effect of trace interval duration. Conversely, in attempting to evaluate a long trace interval, the longer IS1 might lead to poorer conditioning, an effect that could be incorrectly ascribed to the trace interval per se.

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performance as a function of increased CS duration may actually be a consequence of a reduction in the trace interval. Such interrelationships between the independent variables most likely to be examined in a trace conditioning experiment place considerable constraints on the design of any study and the interpretation of its results. The failure to note these constraints may lead to misinterpretations or the appearance of inconsistent results when no inconsistency exists. V. TRACE-OELAY CONDITIONING STUDIES

A. Normal Subject Data 1. SKELETAL RESPONSES

Several early eyelid conditioning studies carried out with normal adult subjects are relevant to the comparison of trace and delay conditioning even though none of these studies make a direct comparison of the effects of the two types of CSs. Bernstein (1934) and Reynolds (1945) both examined trace eyelid conditioning at several ISIs using a click as a CS. The two studies employed different UCSs (shock in the Bernstein study and air puff in the Reynolds study), with Bernstein reporting the percentage of CRs over a l l acquisition trials rather than the asymptotic levels of responding. Despite these differences, however, the results of the two studies were quite similar, with good conditioning evident at ISIs between 350 msec and 1480 msec in the Bernstein study and at ISIs between 250 msec and 1150 msec in the Reynolds study. Kimble (1947) examined eyelid conditioning using a visual delay CS and an air puff UCS with procedures and equipment quite similar to those of the Reynolds study. The IS1 was varied between 100 msec and 400 msec, and although a partial reinforcement test trial procedure was used, the data for anticipatory CRs were quite similar to the Reynolds (1945) data obtained with a trace CS. Thus, comparisons among early studies indicated that a trace CS is as effective as a delay CS in the single-cue eyelid conditioning of normal adults, although such a conclusion was tentative given the variation in procedures and data reporting, and the absence of statistical analyses, which characterize these early studies. More recently trace and delay conditioning of the eyelid response have been compared with single studies. S. M. Ross and Ross (1971) compared trace and delay single-cue eyelid conditioning at seven ISIs from 250 msec to 1400 msec. In this study auditory stimuli were employed, with a trace CS duration of 50 msec. Little conditioning was seen at ISIs shorter than 300 msec, and no differences were found between trace and delay conditioning at any of the ISIs

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examined. A similar study (S. M. Ross, Ross, & Werden, 1974) compared trace and delay differential eyelid conditioning at five ISIs between 300 and 1400 msec using a 50-msec auditory trace CS. Differential responding occurred at ISIs of 800 msec or more; conditioning, but without differential responding to CSt and CS-, was found when the IS1 was 500 msec; and no conditioning was observed when the IS1 was 300 msec. Trace and delay conditioning did not differ at any of the five ISIs. In view of the above studies it appears that ttace and delay CSs are equally effective in both the single-cue and diffetential classical conditioning of skeletal responses in normal adult humans. 2. AUTONOMIC RESPONSES

The data concerning the trace and delay classical conditioning of autonomic responses lead to a somewhat different conclusion. In 1937 Rodnick, in reporting the results of separate trace and delay conditioning experiments with normal subjects, noted that the conditioned response was more difficult to establish when a trace CS was used, and that response latency increased faster when a delay CS was used. In addition, Rodnick reported that on some trials multiple responses occurred during the IS1 (20.1 seconds for delay and 17.4 seconds for trace). The multiple responses were present in both trace and delay conditioning records, and there is some indication that such responses were more frequent with delay conditioning (32% of 48 trials) than with trace conditioning (16.4% of the first 100 trials and 28.6% of trials 301-400). Current research emphasizes the multiple response phenomenon in EDR conditioning (see Prokasy & Kumpfer, 1973 for a summary of this work), and recent experiments with normal adults confirm Rodnick's observations regarding multiple responses in both trace and delay conditioning. Baer and Fuhrer (1968) hypothesized that the EDR trace-delay difference occurred because the contingency between CS and UCS is less apparent to the subject when a trace CS is used. Thus, if level of conditioning is related to the subject's awareness, trace subjects should show a lower level of conditioning and be less able to verbalize the stimulus contingencies. When Baer and Fuhrer compared trace and delay conditioning, however, they found no trace-delay difference in fust interval responses or in responses to the omission of the UCS. Zeiner (1968) has also reported the absence of a trace-delay difference in these two responses. Baer and Fuhrer did find that traceconditioned subjects showed less differential second-interval responding than did delayconditioned subjects. When subjects were divided into those who could and those who could not describe the contingencies between the CSs and the UCS there were more aware subjects in the delay group than in the trace group. However, aware trace subjects failed to show significant differential responding until late in the 28-trial conditioning

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session, while aware delay subjects showed significant differentiation across all trials. When the data for all trials were considered, there was significant differential responding by aware delay subjects but not by aware trace subjects. Thus the authors attributed part of the trace-delay effect to the difference in the number of aware subjects in each group, pointing out that even for aware subjects a tracedelay difference exists in the number of trials necessary for second-interval differential responding to appear. Prokasy, Williams, and Clark (1975) analyzed responses categorized on the basis of latency in an experiment which used a trace CS in the investigation of CS and UCS intensity effects in singlecue conditioning. Although the study does not provide a direct trace-delay comparison, it is worthwhile to note that the frequency of first-interval responses was greater for the various conditioning groups than for their corresponding control groups, but none of the conditioning groups exceeded the control groups in second-interval response frequency. These findings of good frrst-interval responding and poor second-interval responding in the trace conditioning data of normal adults are similar to the results obtained by Baer and Fuhrer (1968). The Prokasy et uZ. data and the Baer and Fuhrer data both suggest that in normal adults the trace-delay variable has its effect on second-interval responding rather than on first-interval or omission responding. A number of other investigators have used trace and delay CSs in both single-cue (Baxter, 1966; GMgs & Schell, 1969; Kimme, 1967) and differential (Cermack & Wickens, 1969) EDR conditioning with adults. Some of these investigators have found trace-delay differences in acquisition (e.g., Baxter, 1966) and others have not (e.g., Grings & Schell, 1969). However, since all used relatively short ISIs and analyzed only one response per trial, it is difficult to compare these results to those of the studies described above. Generally, the normal adult EDR conditioning data seem to indicate that, when multiple responses are examined in long IS1 EDR conditioning, a difference between trace and delay conditioning occurs. This difference is seen in second-interval responding, and the Baer and Fuhrer (1968) results suggest that in differential conditioning the effect is at least partly a function of the subject’s awareness of the stimulus contingencies. In this population, first-interval responses and responses to the omission of the UCS seem to be insensitive to the tracedelay variable. B. Normal-Retardate Comparisons

In 1969 Belmont and Butterfield summarized the literature comparing the trace and delay classical conditioning performance of normal and retarded subjects and concluded that “trace conditioning involving varying demands upon retention does not differentiate Ss of different intellectual levels” (p. 47).

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However, since the time of their review additional data have been collected, and these data, as well as a reexamination of the data reviewed by Belmont and Butterfield (1969), indicate that their generalization may have been incorrect. 1. SKELETAL RESPONSES

Two eyelid conditioning studies (Ross, 1972; Ross & Ross, 1975) have compared trace and delay conditioning in retarded subjects. In the first (Ross, 1972) a 50-msec trace CS was used with trace and delay conditioning groups compared at ISIs of 350,500,800, 1100, and 1400 msec. When the IS1 was 350 msec, conditioning occurred in both the trace and delay groups, but when the IS1 was 500 msec or longer delay conditioning was superior to trace conditioning. These results are in clear contrast to the Ross and Ross (1971) findings, under quite similar experimental conditions, of no trace-delay difference in normal subjects of approximately the same chronological age. Trace and delay eyelid conditioning have also been compared in normal preschool children (Werden & Ross, 1972). In this study trace conditioning with a 50-msec CS and delay conditioning were compared using an IS1 of 800 msec. Delay conditioning was found to be superior to trace conditioning, a result consistent with the Ellis (1963) trace deficit hypothesis which predicts a trace deficit as a function of both M A and IQ. The trace subjects in this study did show a small increase in conditioned responding across trials while the retardates in the Ross (1972) study did not. This effect may be related to the fact that the normal children had a somewhat higher MA than the retarded subjects. Although these results are consistent with the Ellis trace deficit hypothesis, an alternative interpretation involving trace recruitment was possible. If the magnitude of the effective stimulus trace is a function of recruitment processes which take place during or shortly after the CS,then trace conditioning might be expected when CS duration is increased. To investigate this possibility in retardates Ross and Ross (1975) examined trace conditioning in two groups of subjects similar to those in the Ross (1972) study. For both groups, the length of the trace interval was 450 msec, the shortest value at which trace conditioning did not occur in the Ross (1972) study. The groups differed in CS duration with a 50-msec trace CS used in one group (IS1 = 500 msec) and a 500-msec trace CS used in the other (IS1 = 950 msec). The two ISIs which result are within the range of ISIs effective for retardate delay conditioning. Conditioned responding did not occur in either of the trace groups, although it was evident in delay groups conditioned at each of the two ISIS. Since a considerable increase in CS duration did not result in trace conditioning even when the length of the trace interval was close to the minimum value at which the trace deficit appears, the data suggest that the retardate trace deficit is a function of trace interval duration rather than trace CS duration.

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2. AUTONOMIC RESPONSES

A trace-delay difference in retardate EDR can be seen in data obtained by Grings (1969). Retarded subjects’ trace and delay responding were compared using a reinforced test stimulus and an unreinforced control stimulus, the two stimuli differing in modality. In t h i s study, the duration of the trace CS was 5 seconds, and the IS1 was 20 seconds for both trace and delay groups. Thus the trace interval was 15 seconds in length. Subjects in the delay group showed differential first-interval responding to CSt and CS- onsets, but the subjects in the trace group did not. Neither retardate group showed differential secondinterval responding to the CSt and CS-. The Grings (1969) data indicate that the trace-delay variable does effect EDR in the retardate population. However, it is important to note that this retardate trace-delay difference is not the same as the trace-delay difference apparent in the normal adult data previously described. While normals in the Baer and Fuhrer (1968) study showed a trace-delay difference in second-interval responding with no trace-delay difference in first-interval responses or responses to the omission of the UCS, the retardate tracedelay difference seen in the Grings (1969) data appreared in the first-interval response with second-interval responding absent under both conditions. No data seem to be available regarding omission responding by retardates when a trace CS is used. When the delay conditioning results obtained by Grings (1969) are compared to the previously described delay conditioning data obtained with normals, a normal-retardate delay conditioning difference becomes apparent. Normals show both first- and second-interval responding, but retardates show only first-interval responding in the delay conditioning situation. There appears to be no normal-retardate difference in omission responding in delay conditioning (Grings, Lockhart, & Dameron, 1962; Lockhart & Grings, 1964). These results emphasize the importance of analyzing multiple responses when EDR conditioning performance of diverse populations is compared. It is clear that population differences may appear in some components of the response and not in others. Thus if an IS1 of insufficient length is used, or if the various components of the response are not examined separately, real population differences may go undetected. The following EDR studies, which have yielded apparently conflicting results, all employed short ISIs, i.e., those less than 2 seconds, with responding measured on test trials or during extinction. Thus the responses measured in these studies could be first-interval responses, omission responses, or a combination of the two. It is not likely that anticipatory conditioned responses are included, however, since the Grings (1969) data indicate that such responses are probably not found in retardate performance. In spite of the imprecision in response analysis which characterizes these studies, their results do seem to be consistent

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with the Grings and Ross and Ross data indicating that if a UCS of moderate intensity is employed, the retardate trace deficit can be seen when the trace interval is 450 msec or longer. This seems to hold regardless of the duration of the CS,within the constraint that the CS duration and trace interval sum to an IS1 which is effective for conditioning. The results of an EDR conditioning study by Baumeister, Beedle, and Urquhart (1964) are among the most frequently cited data dealing with normal-retardate differences in trace conditioning. In this study normal and retardate conditioning was examined at trace intervals of 0,500,and lo00 msec. The duration of the auditory CS was lo00 msec, resulting in ISIs of 1000,1500, and 2000 msec, respectively. These ISIs were too short to permit analyses of anticipatory responding, test trials were not employed, and thus only responding during extinction was analyzed. Normal-retardate differences were not found at any of the trace intervals, which led the authors to conclude that normals and retardates condition equally well at the three trace intervals examined. The fact that Baumeister et ul. analyzed only extinction data presents a serious problem. No acquisition data were reported, and it is not known whether the normal and retardate groups at each trace interval actually conditioned to the same level of responding prior to the initiation of extinction trials. This information cannot be obtained from the extinction data, since there is ample evidence that extinction data from normal and retarded subjects do not necessarily parallel their acquisition data. Ross, Koski, and Yaeger (1964)and Mosley, Bakal, and Pilek (1974) have both found normals and retardates to attain the same acquisition levels and then show different rates of extinction with normals showing a more rapid decrease in responding during the first few extinction trials. Similarly, Lobb (1968) observed that normal and retardate groups who showed different levels of EDR acquisition, with normals responding at a higher level than retardates, subsequently showed similar responding during extinction. The rapid decrease in responding at the onset of extinction which characterizes the data of normal subjects has been interpreted as indicating that cognitive factors are of considerable importance in extinction. Data from both eyelid and EDR conditioning indicate that if the subject detects or is instructed about the change in stimulus contingencies rapid extinction will occur, while if the change in stimulus contingencies is made less detectable, as when a masking task is used, normal subjects will show more gradual extinction (Grings, 1973;L. E. Ross & Nelson, 1973). Apparently, when normal subjects detect the transition from acquisition to extinction an inhibitory set results, and responding decreases rapidly. There are indications that such inhibitory set factors do not operate as effectively in retardates (Mosley et ul., 1974;L E. Ross et ul., 1964). Since normal-retardate differences in responding during extinction seem to involve processes in addition to those operating during acquisition, and there is no evidence that the groups in the Baumeister e? ul study were at equal

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performance levels at the end of acquisition, the lack of a difference between normals and retardates in these data does not imply similar acquisition for the two groups. Thus the Baumeister et ul. data should be given relatively little weight in the evaluation of normal-retardate trace conditioning differences. Several studies by Lobb and his colleagues have examined the trace EDR conditioning of normal and retarded subjects. The first study (Lobb & Nugent, 1966) compared normal and retardate trace EDR conditioning at two trace intervals (250 msec and 1000 msec) and found a significant interaction between subject class and trace interval length. Normal subjects conditioned at both trace intervals, and retardates conditioned at the shorter trace interval but not at the longer one. These data were interpreted in terms of Ellis’(1963) trace deficit hypothesis. The second study (Lobb, 1968) presumably included a replication of the first, but no significant interaction was obtained, with retardates performing below the level shown by normals at all intervals tested. These results, which appear to be inconsistent, contributed to Belmont’s and Butterfield‘s conclusion that the retardate deficit in trace classical conditioning is an unreliable phenomenon at best. However, a close examination of the Lobb studies reveals that there was an important difference in stimulus conditions between the two studies which may account for the differing results. In these studies, conditioned responding was measured during acquisition by means of a test trial procedure, and thus a partial reinforcement schedule was employed. There is evidence that in classical eyelid conditioning, normals and retardates condition differently under partial reinforcement, although their conditioning performance is similar when continuous reinforcement is used. While it is not known whether the same holds true for normal and retardate EDR conditioning, it seems advisable to consider only the retardate data in the Lobb studies rather than emphasizing normal-retardate comparisons. In addition, half of the subjects in the second study received an amphetamine prior to conditioning and half received a placebo. Only the data for the placebo groups will be considered here. In the earlier study a 1000-msec auditory CS was used with trace intervals of 250 msec and 1000 msec, resulting in ISIs of 1250 and 2000 msec. In the later study the CS duration was only 100 msec and since ISIs of 250,500,1000, and 2000 msec were used, the trace intervals were 150, 400,900, and 1900 msec, respectively. Thus although studies contain groups with similar labels, the stimulus conditions for these groups, shown in Fig. 3, were actually quite different. In the first study retardates showed conditioned responding when the trace interval was 250 msec (IS1 = 1250) but responded at the same level as a sensitization control group when the trace interval was lo00 msec (IS1 = 2000). In contrast the retardates in the 250-msec IS1 group of the second study failed to show conditioning. However, as can be seen in Fig. 3 the stimulus conditions used with this group are not the same as those used with the 250-msec trace

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188 Lobb EL Nugcnt (1966) cs 1250 IS1

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FIG. 3. Schematic representations of CS durations, trace. intervals, and ISIs for trace conditioning groups in EDR conditioning studies by Lobb and Nugent (1966) and Lobb (1968).

interval group of the first study, and the level of conditioning is most probably due to the experimenter's use of an IS1 which was too short for conditioning2 rather than the unreliability of the trace effect itself. The retardates in the 500-msec IS1 group in the second study did show conditioned responding relative to a sensitization control group. Note that in this case the IS1 is within the effective range, and the trace interval is 400 msec in length. No conditioned responding by retardates was found in the second study's remaining trace groups for which the ISIs were 1000 and 2000 msec and the trace intervals were 900 msec and 1900 msec respectively. In both studies when the IS1 was within the range effective for conditioning, trace conditioning was found when the trace interval was 400 msec or less in length in spite of the considerable difference in CS duration. Thus, these data 'When response scoring procedures similar to those used by Lobb are used with a delay

CS, the function relating IS1 and GSR conditioning in normal adults is quite similar to that relating IS1 and eyelid conditioning for ISIs of 500 msec or less (Wickens, 1965; White & Schlosberg, 1952). Thus, while the nature of the response involved is ambiguous, it seems reasonable t o argue that an IS1 of 250 msec is too short for t h i s type of GSR conditioning as well as for eyelid conditioning.

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suggest that trace interval length and IS1 are the relevant variables in retardate trace conditioning and that CS duration is not. This interpretation is consistent with the eyelid conditioning data obtained by Ross and Ross previously discussed. The data from both Lobb studies are also consistent with the other data cited that show a reliable retardate trace conditioning deficit which is seen when the trace interval is 450 msec or more in length, provided the IS1 is appropriate. The third study from Lobb’s laboratory (Carruthers, 1969; Carruthers & Lobb, 1973) examined concurrent trace EDR and eyelid conditioning in retardates. In this study both CS duration and trace interval were varied, and both the EDR and eyelid data outcome led authors to conclude that CS duration was a more important factor in trace conditioning than either trace interval or ISI. Although these results seem to be at odds with the above interpretation, they actually are not. The Carruthers and Lobb study included three trace conditioning groups. For one group the CS duration was 100 msec and the trace interval was 150 msec which resulted in an IS1 of 250 msec. That this group showed poor eyelid and EDR conditioning performance is not surprising given the length of the ISI. The other two groups in the Carruthers and Lobb study were both conditioned at an IS1 of 1150 msec which is an effective IS1 for retardate eyelid conditioning. For one of these groups the CS duration was 100 msec with a trace interval of 1050 msec and for the other the CS duration was 1000 msec with a trace interval of 150 msec. The former group failed to show conditioned responding, but the latter group was superior to both of the other two as would be predicted by the trace conditioning deficit interpretation. The authors contrasted the poor performance of the 250-msec 1%-100-msec CS group and the 1050-msec ISI-100-msec CS group, with the higher level of responding shown by the 1050-msec ISI-1000-msec CS group. They argued that CS duration was the variable which was related to level of responding and that neither IS1 nor trace interval was relevant. However, if the poor performance of the short IS1 group is due to the use of an IS1 of insufficient length for good conditioning, the performance of the two longer IS1 groups is consistent with other data which indicate that when the trace interval is 450 msec or longer retardates show a trace conditioning deficit provided that an effective IS1 is employed.

VI. SUMMARY AND CONCLUSIONS

The data reviewed in the previous section of this chapter indicate that CS duration does not play a major role in retardate trace conditioning. Although the values used have tended to be either short (50 msec) or rather long (1 second), leaving the intermediate range of CS durations unexamined, responding does not seem to be correlated with CS duration.

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E. Ross

The data regarding trace interval length suggest something quite different. Responding was found only in groups for which the trace interval length was 400 msec or less and never in groups for which the trace interval was 450 msec or more. There are two cases in which responding did not occur even though the trace interval was only 150 msec (Lobb, 1968; Carruthers & Lobb, 1973), but these involve groups for which the IS1 was only 250 msec, presumably too short an interval for conditioning to occur. Thus it appears that there is a reliable retardate trace deficit in both EDR and eyelid conditioning. Under conditions similar to those used in these experiments, the critical trace interval length seems to be between 400 and 450 msec, although the EDR conditioning data in this trace interval range are limited. It is possible that further EDR conditioning research using trace intervals between 400 and 900 msec will reveal a somewhat different critical value for the EDR. While the available data suggest that the function relating trace interval length and conditioning is quite similar for both EDR and eyelid conditioning of retardates, there are important differences between the skeletal and autonomic conditioning effects of the trace-delay variable. In eyelid conditioning trace and delay CSs are equally effective for the conditioning of normal adults, while the effectiveness of a trace CS for retardate conditioning appears to depend upon the length of the trace interval. In EDR conditioning, trace and delay CSs are not equally effective for either normal adults or retardates. However, the trace-delay variable seems to affect different components of the EDR in these two populations. For normals trace-delay differences are seen in the secondinterval response, while for retardates second-interval responses seem not to occur in either trace or delay conditioning, and the first-intervalresponse shows the trace-delay effect. These resdts make it clear that when the EDR conditioning performance of different populations is to be compared, multiple responses must be analyzed separately. While the data strongly support a retardate stimulus trace deficit notion, there are several warnings that should be expressed with respect to the generality of the trace deficit data. First, some caution should be exercised in assuming that the trace conditioning deficit demonstrated in the eyelid conditioning of retarded subjects will be found in the same form if different conditioning parameters are employed. Aside from ceiling and floor effects which can always attenuate differences, it is possible that the conditioning situation could be changed, e.g., by varying some reinforcement schedule or UCS parameter, so that a trace deficit either would not be found or would appear at a shorter or longer trace interval. While changing CS parameters might also have such an effect, the evidence cited in this chapter suggests that CS duration is not an important variable. The trace deficit effect might be different, however, if qualitatively different stimuli such as speech sounds were employed as CSs. Since there are no trace-delay eyelid conditioning studies with retarded subjects

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that have employed a visual CS, possibly because the greater difficulty in assuring that the stimulus energy impinges on the receptors, it is not known if an eyelid conditioning trace deficit exists with visual CSs. Second, with respect to EDR conditioning there is considerable evidence that for normal adults relational awareness plays an important if not critical role in the conditioning process (e.g., see Grings & Dawson, 1973). Several investigators have proposed that there is no EDR conditioning without relational awareness, which if true could have major implications for the interpretation of the EDR trace and delay studies cited in this chapter. If should be pointed out, however, that studies investigating relational awareness have generally employed differential conditioning paradigms so their results are relevant to differential responding to the CSt and CS- rather than conditioning per se. AU of the retardate EDR studies discussed in this chapter involved singlecue rather than differential conditioning with the exception of Grings (1969), and even in that study the CSt and CS- were from different modalities. Thus, while relational awareness may play some part in single-cue EDR conditioning, the retardate EDR trace deficit very probably reflects processes other than reduced relational awareness on the part of the retarded. In any case an interpretation of the processes underlying normal-retardate differences in EDR conditioning must await further basic knowledge about EDR multiple response phenomena and the role of relational awareness in EDR conditioning. Finally, note should be taken that the trace deficit may not occur, at least with the same trace interval, after learning has taken place. Evidence relevant to this point was presented by Ross (1972). In this study retarded subjects who had previously been conditioned under delay procedures were switched to trace conditioning. Subjects switched to a 450- or 750-msec trace interval were able to maintain their conditioned responding at a high level, although subjects who started training with those trace intervals did not show conditioning. Thus maintenance of a conditioned response is possible under trace conditions that are insufficient for acquisition of the response. Specification of the conditions under which a stimulus trace deficit occurs and the determination of the implications of the deficit for the general learning and behavioral processes of the retarded would appear to be useful objectives for future research. REFERENCES Badia, P., & Defran, R H. Orienting responses and GSR conditioning: A dilemma. Psychological Review, 1970,77,171-181. Baa, P. E., & Fuhrer, M. J. Cognitive processes during differential trace and delayed wnditioning of the GSR. Journal of Experimental Psychology, 1968,78,81-88. BaumeLstet, A. A., Beedle, R., & Urquhart, D. GSR conditioningin normals and retardates. American Journal of Mental Deficiency, 1964,68,114-120. Baxter, R. Dimunution and recovery of the UCR in delayed and trace classical GSR conditioning. Journal of Experimental Psychology, 1966,3,447451.

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Behrens, R. F. Simultaneous and trace eyelid conditioning in normals and defectives. Unpublished master’s thesis, George Peabody College for Teachers, 1962. Belmont, J. M., & Butterfield, E. D, The relations of short-term memory to development and intelligence. In P. Lipsett & H. Reese (Eds.), Advances in child development and behavior. VoL 4. New York: Academic Press, 1969. Bernstein, A. L Temporal factors in the formation of conditioned eyelid reactions in human subjects. Journal of General Psychology, 1934,10,173-197. Carmthers, B. C. Effects of CS duration on classical conditioning of concurrent eyeblink and GSR in mental defectives. Unpublished master’s thesis, University of Western Ontario, 1969. Carruthers, B. C., & Lobb, H. Effect of CS duration of trace conditioning of mental retardates. Psychological Reports, 1973, 32,1215-1219. Cermak, L. S., & Wickens, D. D. Interstimulus interval and CS duration effects in differential conditioning. Journal of Experimental Psychology. 1969,79, 233-235. Ellis, N. R. The stimulus trace and behavioral inadequacy. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963. Ellis, N. R. Memory processes in retardates and normals. In N. R. Ellis (Ed.), International review of research in mental retardation. Vol. 4. New York: Academic Press, 1970. Pp. 1-32. Estes, W. K. Learning theory and mental development. New York: Academic Press, 1970. Crings, W. W. Anticipatory and preparatory electrodermal behavior in paired stimulation situations. Psychophysiology, 1969,5,597-611. Grings,W. W. Cognitive factors in electrodermal conditioning. Psychological Bulletin, 1973, 79,200-210. Grings,W. W., & Dawson, M. D. Complex variables in conditioning. In W. F. Prokasy & D. C. Raskin (Eds.), Electrodermal activity in psychological research. New York: Academic Press, 1973. Grings, W. W., Lockhart, R. A., & Dameron, L E. Conditioning autonomic responses of mentally subnornal individuals. Psychological Monographs, 1962, 76(39, Whole No. 558). Grings, W. W., & Schell, A. M. UCR diminution in trace and delay conditioning. JournuI of Experimental Psychology, 1969,79, 246-248. Hartman, T. F., & Grant, D. A. Differential eyelid conditioning as a function of the CSUCS interval. Journal of Experimental Psychology, 1962,64,131-136. Hilgard, E. R., & Marquis, D. G. Conditioning and Learning. New York: Appleton, 1940. Holden, E. A., Jr. Stimulus duration and subnormality in visual pattern recognition: A further test of stimulus trace theory. Journal of Comparative and Physiological Psychology. 1966,62,167-170. Hull,C. L Principles of behavior. New York: Appleton, 1943. Hull,C. L Essentials of behavior. New Haven, Conn.: Yale University Press, 1951. Kimble, G. A. Conditioning as a function of the time between conditioned and unconditioned stimuli Journal of Experimental Psychology, 1947,37,1-15. Kimmel, E. Judgments of UCS intensity and diminution of the UCR in classical GSR conditioning. Journal of Experimental Psychology, 1967,73,532-543. Lobb, H. Trace GSR conditioning with benzedrine in mentally defective and normal adults. American Journal of Mental Deficiency, 1968,73,239-246. Lobb, H., & Nugent, C. M. Interaction between intelligence level and interstimulus trace interval in electrodermal conditioning. American Journal of Mental Deficiency. 1966, 70,548-555. Lockhart, R. A., & Grings, W. W. Interstimulus interval effects in GSR discrimination conditioning. Journal of Experimental Psychology, 1964,67,209-214.

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Mosley, J. L., Bakal, D. A., & Pilek, V. Conditioned eyelid response, peripheral vasoconstriction, and attention in retarded and nonretarded individuals. American Journal of Mental Deficiency, 1974,78,694-703. Pavlov, I. P. Conditioned reflexes: An investigation of the physiological activity of the cerebral cortex. (Transl. by G. V. Anrep). London: Oxford University Press, 1927. Pavlov, I. P. Experimental pathology of the highest nervous activity. Leningrad: Ogiz,1935. Rokasy, W. F., & Kumpfer, K. L. Classical conditioning. In W. F. Rokasy & D. C. Raskin (Eds.), Electrodermal activity in psychological research. New York: Academic Press, 1973. Prokasy, W. F., Williams, W. C., & Clark, C. G. Skin conductance response conditioning with CS intensities equal to and greater than UCS intensity. Memory and Cognition, 1975, 3, 277-28 1. Reynolds, B. The acquisition of a trace conditioned response as a function of the magnitude of the stimulus trace. Journal of Experimental Psychology, 1945,35,15-30. Rodnick, E. H. Characteristics of delayed and trace conditioned responses. Journal of Experimental Psychology, 1937,20,409-425. Ross, L. E., Koski, C. H.,& Yaeger, J. Classical eyelid conditioning of the severely retarded: Partial reinforcement effects. Psychonomic Science, 1964,1,253-254. Ross, L. E., & Nelson, M. N. The role of awareness in differential conditioning. Psychophysiology, 1973,10,91-94. Ross, S. M. Trace and delay classical eyelid conditioning in severely and profoundly retarded subjects as a function of interstimulus interval. American Journal of Mental Deficiency, 1972,77,39-45. Ross, S. M., & Ross, L. E. Comparison of trace and delay classical eyelid conditioning as a function of interstimulus interval. Journal of Experimental Psychology, 1971, 91, 165-167. Ross, S. M., & Ross, L. E. Stimulus input recruitment and stimulus trace decay factors in the trace conditioning deficit of the severely retarded. American Journal of Mental Deficiency, 1975,80,109-113. Ross, S. M., Ross, L. E., & Werden, D. Trace and delay differential classical eyelid conditioning in human adults. Bulletin of the Psychonomic Society, 1974, 3,224-226. Scott, K. G., & Scott, M. S. Research and theory in short-term memory. In N. R. Ems (Ed.), International review of research in mental retardation. Vol. 3. New York: Academic Press, 1968. Werden, D., & Ross, L. E. A comparison of the trace and delay classical conditioning performance of normal children. Journal of Experimental Child Psychology, 1972, 14, 126-132. White, C. T., & Schlosberg, H. Degree of conditioning of the GSR as a function of the period of delay. Journal of Experimental Psychology, 1952,43,357-362. Wickens, D. D. Compound conditioning in humans and cats. In W. F. Prokasy (Ed.), Classical conditioning: A symposium. New York: Appleton, 1965. Zeiner, A. R. Second interval discrimination conditioning of the GSR as a function of UCS intensity and trace and delay conditioning paradigms. Journal of Experimental Psychology, 1968,78,276280.

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Malnutrition and Cognitive Functioning J. P. DAS AND EMMA PIVATO' CENTRE FOR THE STUDY OF MENTAL RETARDATION AND DEPARTMENT OF EDUCATIONAL PSYCHOLOGY, UNIVERSITY OF ALBERTA, EDMONTON, CANADA

.................................................. ............ A. General Review .............................................. B. Design of Malnutrition Studies .................................. TheOrissa Study ............................................... A. Classandcaste ..............................................

1. Introduction

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B. Measures of Cognitive Competence C. Method D. SomeHypotheses E. Results F. Discussion summary References

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1. INTRODUCTION

An ecological approach to malnutrition has been adopted in the present chapter in order to relate it to cognitive competence. One may view the relationship in the context of social cultural factors which coexist with malnutrition, and assess competence also in the context of the conditions in which it is displayed. We know that malnutrition is a man-made disorder. It appears in endemic form in certain segments of society and in certain regions of the world. It is not a disease, although a severe deficiency in protein-calorie results in marasmus or kwashiorkor, which require hospitalization.

'Emma Pivato is coauthor for the review part of this chapter. 195

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A disease model of malnutrition is at variance with the ecological approach. It can distract one from a proper understanding of the dimension of the problem. It encourages fatalism-the mother assumes that the child’s illness is the fault of

no one, and that it could not have been prevented. Such beliefs can interfere with her understanding of nutritional instruction, and with the rehabilitation of the child following the treatment for malnutrition. A “disease” also implies a cure. The family and the community at large may feel that once the child has recovered from the disease, he will be back to normal, and no long-term rehabilitation measures will be necessary. As an illustration of how malnutrition may be an ecological phenomenon, one may cite the longitudinal study of Cravioto and Delicardie (1972). Their project, operating in a Mexican village, monitored the nutritional status of babies from prenatal to postnatal stages. In the village, infections, infestations, poverty, and illiteracy were not at all uncommon. But after Cravioto’s project started, the village came to have three pediatricians, four psychologists, ten social workers, and two administrators, all of them concerned with the prevention of malnutrition. In spite of this, 22 children developed signs of severe malnutrition. One does not suspect that adequate diet was lacking. It was the quality of home environment, the attitude of the mother, the lack of education; in other words, there were factors in the child’s microenvironment which contributed significantly to the development of the clinical signs of malnutrition. The present chapter is divided into two major parts, a review and an experiment on the effects of malnutrition. 11. PROTEIN-CALORIE MALNUTRITION (PCM) AND MENTAL DEVELOPMENT

A. General Review

The relationship between malnutrition (PCM) and subsequent mental development in humans has been very closely examined during the past decade. Kaplan (1972) has recently provided a review of most of the major studies which associate malnourishment to mental deficiency. However, many elements of this association still are not clearly understood. Peak development of the human brain occurs before birth during the third prenatal trimester. Severe maternal malnutrition at this time can reduce the protein and DNA content in the fetal brain, permanently reducing brain cell number (Winick & Rosso, 1969). Whether or not such damage can lead to permanent intellectual retardation has not yet been established. However, Beargie, James, and Green (1970) have shown that the small-for-date newborn lags developmentally behind his control. Even if this developmental lag could eventu-

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ally be outgrown, it may not be easy to make up for the loss of learning time during the critical early years of mental development. The relationship between low birth weight and intellectual impairment only holds, however, in cases of true intrauterine growth retardation and not in cases of premature birth (Chow, Blackwell, & Sherwin, 1968; Platt & Stewart, 1971). The human brain is still developing very rapidly during the first 6 postnatal months of life and is therefore vulnerable to damage from PCM. If maternal lactation is adequate, the infant’s nutritional needs can be met. However, lactation can itself be affected by malnutrition. Severe PCM at the time of the mother’s own physical development can seriously impair her lactating ability (Stewart, 1968). Poor nutrition during or after pregnancy can reduce the quantity and quality of her milk (Manocha, 1972). Many researchers believe that once a child has reached 6 months of age the major danger to the brain from malnutrition is over. Dobbing (1974) suggests that the myelin sheaths in the brain are synthesized during this dmonth period and, once completed, their “remarkable stability” protects the brain from any irreversible damage due to PCM. However, Counin (1965) has suggested that the critical period of brain myelination can extend over the fust 4 years of life, and that even short periods of PCM occurring at a critical period during this time can cause permanent damage. How does malnutrition affect brain myelination? It can alter amino acid metabolism, possibly by interfering with the development of the enzyme system responsible for the conversion of phenylalanine to tyrosine (Eichenwald & Fry, 1969). The effects are similar to those in phenylketonuria, although probably not as severe (Kotch, 1970). There is a selective depression of amino acids resulting in a high concentration of phenylalanine in the brain which may lead to irreversible brain damage (Coursin, 1965). How critical is the balance between protein and calorie? If adequate calories and marginal protein are available in the diet, protein utilization is very efficient (Edozien & Obasi, 1965). Munro and Allison (1964) attributes this to the protein-sparing action of carbohydrate. However, if either calories or protein are too restricted, the body is unable to utilize the available protein well. Grimble and Whitehead (1971) suggest that “preferential synthesis of muscle protein in response to insulin secretion” does not take place if the serum amino acids are too limited. According to Morrison and Rao (1967), inadequate calories produce a similar effect. If there are not enough calories available to supply the basic energy needs of the body, dietary and even tissue protein are catabolized for this purpose and the freed nitrogen is excreted in the urine. Even when adequate protein is available in the child’s diet, it may not be absorbed. Most of the children in the malnourished communities have infections and infestations which interfere with the proper utilization and absorption of dietary protein. Scrimshaw, Taylor, and Gordon (1968) consider the relationship between infection and malnutrition to be a “synergistic interaction,” meaning

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that when both conditions are present one aggravates the other. Infection compounds the effects of PCM in two ways. First, it leads to a high rate of protein catabolism. During a severe illness, the body may catabolize as much as 135 gm of protein a day in its attempts to defend itself against the disease organisms (Co Tui, 1953). This could be at least five or six times the daily protein intake of a child in proteindeficient areas of the world. Second, when diarrhea is involved, much dietary protein is leached out of the system before it can be metabolized. Illness has such a depleting effect on the body protein supplies that some researchers consider it to be the main precipitator of PCM. Few cases of malnutrition acute enough to be hospitalized are found to be free from infection on admittance. In addition to infections, worm infestation is a contributing factor to malnutrition. Tripathy, Gonzalez, and Lotero (1971) found that abnormal amounts of fat and nitrogen were being excreted in the feces of 12 malnourished Colombian children with Ascaris infestation. The resulting loss of dietary protein and calories could aggravate an existing deficiency. Another line of evidence suggests that malnutrition can reduce the offspring’s competence in fighting infections. Chandra (1975), for instance, considers intrauterine malnutrition to be a major cause of immunodeficiency. The cultural peculiarities of a community or region where malnutrition is widespread can act directly to increase malnutrition and to interfere with rehabilitation. These can also obscure the nature of the PCM damage; usually the cultural milieu can be characterized as unstimulating. As such, it will not reveal the child’s deficiencies nor will it encourage him to overcome them (Birch & Gussow, 1970). There is great variation between cultures as to what is considered appropriate food for children. In some cultures it is traditional to give most of the more nutritious foods to the older members of the family, on the assumption that the younger children do not require it. Meat is not given to children in some areas because it is believed they cannot digest it Gotch, 1970). Thus, cultural traditions can affect feeding patterns adversely even in well-educated families with ample means. Several familial factors are closely related to malnutrition in children. For instance, Chase and Martin (1970) found that the common element underlying all the factors-a large family, more children under age 2, poverty, paternal separation, and alcoholism-was the additional stress they placed on the mother. Similarly, Cravioto (1967) noticed that the mother’s educational background was directly associated with developmental level of the child as assessed by intersensory organization. His explanation was that the better educated women were less bound by tradition in methods of feeding and child care. However, the explanation does not support a purely environmental determination; there could also be a mediating genetic factor in the relationship between mother’s education and child’s developmental level. Monckeberg (1968) found that the IQs of

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the mothers of malnourished children tended to be lower than the IQs of the mothers of well-nourished children. He also observed a positive correlation between maternal and child IQ in the malnourished group, Apart from family conditions the motivational condition associated with PCM can be important. Apathy is ftequently found in malnourished children. It may affect learning, thereby indirectly affecting IQ. Apathy and withdrawal characteristic of PCM children lead to a self-imposed lack of environmental stimulation. This results in a high degree of sensory deprivation (Pollitt, 1969). Grotberg (1970) has suggested that sensory deprivation at crucial periods during development can result in permanent organic impairment or nondevelopment of neural structures. However, how severe would be the sensory deprivation in order to retard development is still an unresolved issue @as, 1973a). The apathy which accompanies severe malnutrition is most unlike the restlessness which characterizes hunger. It has been suggested that apathy is due t o separation trauma which occurs when the PCM child is hospitalized for his condition. However, Cravioto and others have observed the same severe withdrawal in the PCM children when they are at home. Eichenwald and Fry (1969) point out that apathy is accompanied by electroencephalographic changes in the brain, and when these return to normal, the apathy tends to disappear. This observation agrees with the notion that one of the earliest signs of recovery from PCM is a return of responsiveness to the environment. The major influence of malnutrition, according to some researchers (Rio cuitti, 1972), may be displayed in attentional, arousal, or motivational responses in children, rather than in their basic intelligence and competence in learning. If this is so,then it would follow that apathy is the major cause of the developmental lag found in PCM children. It could either result in retardation by preventing attention to the environment during critical learning periods or, if PCM occurred at a later stage of development and over a long period of time, it could result in a “cumulative deficit” (Kotch, 1970). This would interfere with learning and intellectual ability indirectly since the child would not have acquired the proper foundation for later intellectual development. An indeterminate number of ecological variables are associated with PCM, and they are extremely difficult to control for in research projects. Pollitt (1969), in his examination of this problem, contends that none of the behavioral studies on the relationship between PCM and mental development has taken full account of these cultural variables, and he suggests that until they are fully assessed, it cannot be determined whether or not the intellectual impairment found in PCM cases is due to organic damage to the brain. In the Colombo study which is to be described later, we have attempted to control for the major ecological variables. In concluding this section, the following points about the relationship between PCM and mental development were made.

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1 . Malnutrition does not exist alone. It is complicated by social factors such as low socioeconomic status, susceptibility to childhood diseases, and poor educational level of parents, particularly of the mother. 2. The effects of severe malnutrition on cognitive development are probably most visible if marasmus or kwashiorkor has occurred before age 2, but such effects are not quite irreversible. Beyond that the evidence is not consistent. 3. Less severe poverty and malnutrition have an adverse effect on the school achievement of the child, but it is doubtful that this could be traced to brain development. The effect, on the other hand, might be produced by lack of attention and motivation. B. Design of Malnutrition Studies

The basic problem here is to isolate the effect of malnutrition from the effects of coexisting factors. Subsequently, there is a need to identify the specific mental functions which may deteriorate or fail to develop fully in children who have gone through a period of severe malnutrition. The logic behind isolating the effect of malnutrition is not clear. For if severe malnutrition seldom occurs alone in humans, it may be unnecessary to study its effect by itself. The relative contributions of factors associated with malnutrition are to be determined along with the unique contribution made to mental retardation by malnutrition. Different designs allow us to assess these, some to a greater extent than others. Three kinds of studies can be carried out in order to determine the effect of malnutrition and its associated conditions: (1) prospective, (2) retrospective, and (3) anthropometric. The first two involve children who have been hospitalized for PCM, whereas the last is done on nonhospitalized children. 1. PROSPECTIVE STUDY

Prospective longitudinal studies are the best for detecting the influence of clinical malnutrition and its associated factors. Cravioto and DeLicardie (1972) have been conducting such a study in a Mexican village, observing children from birth to 7 years of age. At age 7, the children will be in elementary school and can be given psychological tests. The experimental group comprises those children who develop clinical malnutrition, whereas the control group will comprise their agemates from the same village. Such a control group has unique advantages over a random group of nutritionally adequate children; the two groups of children have grown up together in the same environment. The study recognizes that malnutrition is an “ecological event,” and uses ecological methods to examine (1) the extent to which social, economic, and family conditions influence the development of malnutrition; (2) the effect of malnutrition on physical growth and intellectual performance; and (3) the interactions between the eco-

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logical and nutritional factors as these are revealed in the child’s physical and intellectual growth. The investigators are discovering definite retardation in language behavior among the malnourished children even before the age of 7. For example, they find that after recovering from severe malnutrition, the children at the age of 46 months have significantly fewer concepts than their control counterparts. How important are the ecological factors according to the results of the study which are already available? Here we have some surprises. Biological characteristics such as parents’ height and weight, and the number of children in the family have no connection with the development of malnutrition in the family, nor do social-cultural variables such as personal hygiene or education of the parents distinguish the families of control children from the families of malnourished children. However, on the amount of home stimulation (adult contact, vocal stimulation, avoidance of restrictions, availability of toys, etc.) the control group is at a higher level. In their interim report, Cravioto and DeLicardie observe that they are not sure for how long the control children will continue to be superior in their language scores to the malnourished children. 2. RETROSPECTIVE STUDY

Where a prospective longitudinal study of severely malnourished children is not possible a retrospective method is often adopted. This too requires children who have been hospitalized for severe malnutrition, preferably before the age of 2. Such children are usually given tests of intellectual abilities when they reach school age (Champakam, Srikantia, & Gopalan, 1968; Richardson, 1972), although younger children may be tested. The age at which clinical malnutrition was first noticed in the child is an important factor. Recent researchers appear to have considered age 2 rather than an age of 6 months to be the critical age (Hertzig, Birch, Richardson, & Tizard, 1972). Champakam et al. working at the National Institute of Nutrition in India, assumed that malnutrition occurring even at the age of 3 affects cognitive functions of the child when he is tested between the ages of 8 and 11 years. Retrospective studies present as many problems as prospective ones. Quite often, in underdeveloped countries, hospital records are not accurate. The criteria for entering a diagnosis of malnutrition vary widely between the attending physicians. Thus, ideally the same physician should be in charge of a malnutrition unit in the hospital for about 6 to 8 years so that the researcher can go over the records with the physician and select the “true” cases of malnutrition. This becomes especially important, because in those regions of the world in which malnutrition usually occurs, many superficial signs of it, such as edema, may be commonly shared with infections and infestations of various kinds. In some regions of India, the accurate birthdate for the child may not’be available. Birth certificates are not required. If the baby is born at home rather than in the

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hospital, it is not easy to get an accurate date of birth. Lower class parents may not have this information, and upper class parents may falsify the date of the baby’s birth in public records such as in registration forms for entering the elementary school. In addition to this, record keeping in the hospital is not organized for easy retrieval, especially those records which are as old as 6 years. The hospitals in India, for instance, have to deal with an extremely large number of cases but have severely inadequate financial and clerical support. A good retrospective study not only needs accurate hospital information, but appropriate control groups. What should constitute a control group for the malnourished child or the index case? A child of comparable age without the history of severe malnutrition can constitute a control group. The control and the index case, of course, must come from the same low socioeconomic status and preferably be in the same school and in the same grade. Index cases, however, are frequently school dropouts. They also come from unstable families. Matching a control subject in each of these relevant characteristics to an index case becomes not only impractical but infringes some of the basic assumptions of sampling. It is apparent from the review of Warren (1973) and several methodological papers (cf. Hopkins, 1969; Stanley, 1967) that one-to-one matching techniques for comparing index cases with a control are not defensible. Strict matching of this sort restricts both the internal and external validity of comparisons and reduces the generalizability of the fmdings. The matched control group, simply, may not represent any real population. Gottfried (1973) considers this problem in reviewing the effect of perinatal anoxia on intelligence and rejects matching. He recommends, instead, the following: “a more fruitful approach would be to study the relationship between anoxia and IQ in its natural interplay with other covariances rather than in an artificially isolated context” [p. 2401. The use of multiple correlations can fm the relative saliency of a number of variables associated with PCM. A determination of the relative contribution of these factors, in turn, will guide us in designing programs with a view to prevent the deleterious effect of malnutrition. There is the need for another kind of control, the need to partial out the genetic factors inherent in a family in which malnutrition occurs. The best one can do is to include the sibling of the index case in the study and compare the sibling with his or her classmate of equivalent age and socioeconomic status. Thus, a retrospective study will have four groups: (1) the index case, (2) his control, (3) the sibling, and (4) his control. A comparison between (1) and (2)may tell us to what extent malnutrition and other environmental factors depress cognitive functioning, but the result will be confounded by genetic propensities which may facilitate both the occurrence of malnutrition and the poor cognitive functioning. A comparison between (3) and (4) will, then, be necessary to take this into account. One has to show that the difference between (1) and (2) is greater than the difference between (3) and (4). Many practical difficulties, however, may hold back the researcher from these ideal compari-

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sons. The problem of finding an index case and his or her sibling of the same sex who is relatively close in age is one such detractor from achieving the ideal statistical design. Often the sibling is not the same sex. Further, he is so much older that the tests of cognitive competence cannot be appropriate for both ages; the comparison becomes inappropriate from a developmental point of view. In the research project currently continuing in Colombo, Sri Lanka,we are attemp ting to get as many subjects as possible in the fourfold ideal design for a retrospective study. We have in our team the head pediatrician of the malnutrition unit who had first admitted the child to the malnutrition ward of the hospital about 6 years ago. It ensures that the criteria for clinical malnutrition have been the same for all children in our project. 3. ANTHROPOMETRIC INDEX: HEIGHT

Differences in height constitute one of the familiar anthropometric measures for relating reduced intelligence to PCM. Children suffering from severe marasmus or kwashiorkor during infancy are usually stunted in their growth. Garrow and Pike (1967) have argued that although the effect of undernourishment on body size is well established in animal samples, it is not so clear in human samples. Their experiment on the long-term prognosis of severe malnutrition in infants carried out on Jamaican children indicated the possibility that children who have been clinically malnourished might have a genetic component to outgrow their siblings when they are nutritionally rehabilitated. Why, then, is it generally found that malnourished children are relatively stunted in height? Garrow and Pike point out that most of these findings relating to stunting of growth were based on comparisons of malnourished children and control children from different families. Perhaps it is not surprising that the children who are malnourished usually come from families who exist on a subsistence level, and the average height of children in these families would be lower than a comparable group of children from the normal population. Cravioto (1967) found evidence of a relationship between height and intersensory organization (his criterion for normal development) in the rural but not in the urban subjects of his study. Krueger (1969), who did find evidence of depressed height in her 152 PCM subjects, observed that the two postpubertal girls in the study fell within the normal height-for-age range. On the basis of this observation, she speculated that height may be temporarily but not permanently depressed by PCM and that it may be compensated for by an adolescent growth spurt. Sanstead, Carter, House, McConnel, Horton, and Vander Zwaag (1971) also found a positive correlation between reduced height and vitamin A deficiency. Reduced height could be only one of many possible adaptations by the body to chronically poor nourishment. Manocha (1972) suggests there may be a "genetically based variation in physiological adjustment which prevents so much mental damage in populations all over the world living on barely subsistent diets." The tendency to think of PCM as a disease and to think of all the

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physical factors associated with it as symptoms may have prevented other adaptive mechanisms from being recognized. For example, reduced head circumference and brain cell number, two other commonly used anthropometric measures of PCM brain damage, are also adaptive to a certain degree. Garn (1964) has shown that head circumference can be reduced under PCM conditions by the thinning of skull bones and the loss of temporal musculature. Winick and Ross0 (1969) have demonstrated that severe PCM can greatly reduce RNA in the brain, which in turn is an indication of reduced brain cell number. As an anthropometric measure of the effect of cumulative malnutrition, height is not an accurate index. Whereas children who have a history of clinical malnutrition tend to be short-statured compared to normal children of the same age, it cannot be assumed that all children who have short stature have experienced severe malnutrition. But, if one wishes to use height as an index, one should take children from low socioeconomic status where malnutrition occurs in an endemic form and ideally partial out parental height. The design adopted by Cravioto and DeLicardie (1972) is essentially a good one to follow in research where height is taken as an index. They used two groups of children from the same population and from the same ethnic background within the age range of 6-1 1 years. Then they compared the upper and lower quartiles by height in each age group on a psychological test of intersensory organization. In order to prove the point that in the higher socioeconomic class height would not be a salient variable affecting psychological processes, they took an upper-class urban group of school children and divided them into short and tall groups; as expected, the comparison did not yield a significant difference. Even among the lowsocioeconomic class children from urban areas little difference was noticed between short- and tall-statured subjects. Cravioto remarked that in the rural area the malnourished child is completely at the mercy of his environment. 111. THE ORlSSA STUDY

We are using height as an index in an ongoing project in India’s Orissa State. The complexity of such a study is vastly increased when one wishes to carry it out in a traditional society. For instance, in addition to controlling for the effect of age and educational level, social class, and urban or rural residence, one has to consider the effect of membership in high and low caste. The latter interacts with socioeconomic conditions. An elaboration of the role of caste and socioeconomic status is called for at this point. A. Class and Caste

The disadvantages of belonging to the lower economic class are well documented (Deutsch dc associates, 1967). The term “culturally disadvantaged” in fact refers to the poor intellectual ability of children in the low socioeconomic

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class. Although the poverty of culture among the lower class of people has been assumed to be universal, such an assumption may not be valid for India where the high caste is supposed to have a culture superior to that of the low caste given the same low socioeconomic class. The high-caste Brahmin, being the highest caste, is assumed to have a culture which encourages intellectual achievement. In contrast, the lowest caste, Harijan, is not known to have a scholastic tradition as the Brahmin has. Apart from sociocultural factors which m a t favor cognitive growth in Brahmins, there may be genetic advantages. If one believes in the legend of the origin of the caste system, the Harijans are, to start with, the slaves of the caste Hindus. They were supposed to be inferior in intellect and did the most menial jobs. In contrast, the Brahmin was the interpreter of religious texts, advisor to the king, and was generally regarded as a source of wisdom. Both of these castes have been inbreeding for hundreds of years. It would seem then that the Brahmins have the advantage of a scholastic environment and a superior genetic stock to start with. The cumulative effect of these factors would be an increasing gap between the Brahmins and the Harijans. Brahmins themselves can be divided into upper and lower economic groups, but Harijans are overwhelmingly in the lower economic class. The upper-class Brahmin child certainly grows up in a superior social-cultural environment in contrast to the lower-class Brahmin child. Hence, in cognitive tests, he should do better than the poor Brahmin child. Compared with a Harijan child of low economic class, the poor Brahmin child, one assumes, has grown up in an environment which facilitates intellectual growth. One should remind oneself that this is merely conjecture, as we do not have any studies in India to show exactly how the scholastic traditions which may exist in a poor Brahmin home may influence the child-rearing practices and the day-to-day interactions between the child and the parents or other elders. Thus, the supposed difference between the poor Brahmin and the poor Harijan child in intellectual ability is based on historical rather than psychological facts. The specific design of the study is as follows. The study examines four groups of children divided on caste and height. All the groups belong to the lower socioeconomic class. The four groups are tall and short Brahmin children and tall and short Harijan children. Their ages are between 9 and 11 years, and all of them go to school and are in grade 5 . All subjects are boys. First of all, a distribution of heights of a large number of 9-, lo-, and 11-year-old Brahmin boys is obtained. The same is done for Harijan boys separately. The highest and lowest 25th percentile of height for each age group is determined. Then, only those children who fall in the 25th percentile ranges are chosen for inclusion in the sample of tall and short boys from each caste. The reason for classifying children into tall or short stature separately for each caste is to guard against possible genetic differences which may determine height in the two castes. The design fits into a 2 (short and tall) X 2 (low and high caste) factorial analysis of variance.

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B. Measurer of Cognitive Competence

The other major problem in the design is to find a proper method for determining mental ability. In the past, IQ tests of various kinds have been used to detect the depression of intellectual ability resulting from malnutrition. Sometimes, the difference in IQ has been found to be too small for serious consideration. The other tests that have been infrequently used are Reading Achievement and Cross-Modal Coding. Sometimes crossmodal coding is called intersensory integration because the child receives the input through one modality, for example, a pattern of sound, and then is asked to judge visually from a pattern of dots (Birch & Gussow, 1970). He has to say whether or not the sound pattern matched the dot pattern. None of the researchers in the area of malnutrition, however, has gone deeply into the problem of measuring cognitive competence itself. It is evident that our knowledge of cognitive competence is rather poor. How do you spot a competent child, or, alternatively, how do we construct a series of tests to measure cognitive competence? Broadly speaking, competence is manifested in academic work or in school learning. In American and European schools, reasoning and verbal abilities are selectively reinforced. Children who are good at both reasoning and language are thought t o be superior in ability to those who are poor in these skills. School systems in underdeveloped countries where malnutrition occurs in endemic form more or less emphasize reasoning and language too. Especially in the early school years, teaching of numerical and verbal skills become the major tasks in all schools. Reasoning and memory refer to a hierarchical structure of abilities, reasoning being at a higher level than memory. Recently we @as, Kirby, & Jarman, 1975) have proposed an alternative to reasoning and memory. The alternative refers to two information-processing modes: simultaneous and successive. Simultaneous and successive processing are viewed as habitual modes of processing information employed by an individual while solving several cognitive problems. Both are centrally mediated processes, are parallel to each other rather than hierarchical, and are available to any individual for use by him according to the nature of the task as well as on the basis of the individual’s preference for one or the other method of information integration. We recognize that cultural and individual preference for the use of a specific mode of processing does exist @as, 1973a). How do these modes of processing information relate to intelligence? We believe that intelligence does not inhere in a preference for reasoning over memory, nor does it evidence itself by a facility in using a simultaneous rather than a successive mode. Rather, intelligence manifests itself in the use of information obtained through these transformational procedures in order to plan and structure behavior effectively for goal attainment. A description of the two modes is given by describing the tests which measure them. We have used a battery of tests which measures three distinct kinds of

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cognitive processes. These are simultaneous, successive, and the speed of processing. The simultaneous processes are tapped by tests such as the Progressive Matrices (Raven, 1956) and Figure Copying (Ilg & Ames, 1964), the successive by tasks such as serial recall of short lists of words and digit span (Das, 1973a). The model of simultaneous and successive processing has been borrowed from Luria (1966) which can be described as follows: Simultaneousintegration refers to the synthesis of separate elements into groups. These groups often have spatial overtones. The essential nature of this sort of processing is that any portion of the result is at once surveyablewithout dependence upon its position in the whole. For example, in order for the individual to grasp systems of relationship, it is necessary that the components of the systems be represented simultaneously. In this way, the relationships between components can be explored and determined. Successive processirig, on the other hand, refers to processing of information in a serial order. The important distinction between this type of information processing and simultaneous processing is that in successive processing the system is not totally surveyable at any point in time. Rather, a system of cues consecutively activates the components. Although the two processes, simultaneous and successive, may superficially resemble reasoning and memory, they are not found to be so in empirical studies (Das, 1973b; Das & Molloy, 1975). To illustrate, a simple skill such as watch repair could be entirely subsumed under the first. On the other hand, verbal comprehension may need successive synthesis to a great extent. Certainly verbal comprehension does not depend entirely on memory. Thus, rather than assessing the effect of malnutrition by a global IQ test, one must look at the processes that are involved when an individual is functioning in a test situation. It is quite possible that malnutrition depresses one kind of functioning rather than the other. The battery of tests which we have used has measures of simultaneousand successive processing as well as the speed of processing. The effect of malnutrition may be observed in some or all of these three processes. C. Method

The subjects were 360 boys from the high (Brahmin) and low (Harijan, formerly “untouchables”) castes. They were in Grade 4 of neighborhood schools. In addition to caste, residence in urban or rural areas was a variable for the low-caste samples: The low-caste children were from rural and from urban areas, whereas all high-caste children were from the rural area. In order to divide the boys into tall and short groups, a distribution of the heights of a large number of boys in each caste was obtained, and the 25th and 75th percentiles were calculated. This was done for ages 9-1 1 for the high caste and ages 9-12 for the low caste as these were the range of ages found in Grade 4 of the local schools. Upper and lower quartiles of heights are given in Table I. Following the initial calculation of percentiles, the samples for the study were

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J. P.Das and Emma Pivato TABLE I UPPER (75th PERCENTILE) AND LOWER (25th PERCENTILE) QUARTILES FOR HEIGHTS (IN INCHES)

9

10

11

12

Tall Short

51 46

52 48

54 49

-

Low caste Tall Short

51 41

53 48

54 49

51 52

High caste -

selected. Only children from the low income group were included. Their family income was $40.00 (300 rupees) or less a month. Standing height of the children was measured by a portable wooden ruler and pedestal. The first step was to select an elementary school in a rural or urban area, and obtain permission for testing Grade 4 children. Then Brahmin and Harijan boys were identified by going through the class registration list with the class teacher. All eligible boys were then gathered and their heights measured. Only those who were above the 75th percentile (tall) or below the 25th percentile point (short) for their age were accepted. Since in this project we wished to record parents’ heights, a further stipulation was that the child must have both parents living. Age of the child was determined by taking into consideration his date of birth as mentioned in the school register, and then the figure was checked with the teacher. In case of doubt, the teacher’s estimate was accepted. It is difficult to find out the exact age of the child, as most children do not have a birth certificate. Only when a baby is born in a hospital can a birth certificate be obtained; but almost all rural children were not born in the hospital. Complicating accurate maintenance of birth records was the illiteracy of parents-less than 45% of the males and 12% of the females can read at Grade 1 level in the rural areas. These percentages are still lower for the low caste. At the time of admission to the school, one of the parents may accompany the child, and it is he or she who gives the child’s age. We recorded the child’s age in terms of the nearest whole number (9, 10, 11, or 12) because the data were no more accurate than that. The age is thus the “declared age.” It is not grossly inaccurate-the average correlation (r) between age and height in our subject sample of 360 boys

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is .70. For the tall group (N = 120), r = .64and for the short group (N=120), r = .76. Sample characteristics such as age and height are given in Table 11. Residence in urban or rural areas also implies that the child went to a school located in his neighborhood. Rural children lived in villages which are defined as a settlement (for revenue purposes) containing less than 5000 persons. Urban children lived in towns of more than 5000 persons within a municipality. In terms of occupation, the majority in the towns have nonagricultural professions as a means of livelihood. The project was located in the coastal part of Orissa, a relatively poor and small state (population 20 million) in the Indian Union. According to official estimates of the Indian Government, 60%of its people live below the poverty line. The major focus of the project was on the rural samples, comparing the intellectual performance of short and tall children in two castes. Urban low-caste children, however, were also included to determine the beneficial effect which town living may have on cognitive development of low-caste children. Past studies in Orissa (Das,1973a; Das & Singha, 1975) had shown no difference between rich and poor high-caste children as far as performance on cognitive tasks was concerned. We assumed that we are unlikely to obtain a difference among high-caste urban children when only the economically poor are taken and

TABLE I1 SAMPLE CHARACTERISTICSa

Rural low caste

Urban low caste

Rural high caste

Characteristics

Tall

Short

Tall

Short

Tall

Short

Child’s age M SD

10.13 1.05

10.41 1.15

9.85 .79

10.45 .95

9.93 .75

9.98 .69

Father’s height M SD

64.12 2.88

62.77 3.24

64.05 1.95

63.12 2.42

65.00 2.38

64.58 3.03

Mother’s height M SD

59.63 2.71

59.10 2.65

58.96 2.87

59.37 2.41

60.16 3.02

59.70 2.47

Child’s height M SD

54.48 2.82

48.40 2.38

53.72 2.37

48.05 1.92

53.16 1.77

47.46 1.29

~

O N = 60

in each group.

~~

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compared on the basis of height, because the much more powerful rich-poor contrast did not show differences in intellectual performance. The low-caste children living in towns may compensate for the presumed lack of intellectual stimulation at their homes because of their exposure to the enriched urban environment. If t h i s were the case, the urban group as a whole, irrespective of height, will be superior to the rural group. But it is not clear if the tall-short difference in the cognitive tests will be narrowed. TESTS

A battery of tests was administered to the children; the tests had been shown to measure simultaneous and successive processing and the speed of processing @as, 1973b; Das et al., 1975). The nature of the tests as defined by the performance of the various samples in this study will become apparent later while considering the factor analyses of the test battery. Testing was conducted at the schools of the participating children. Usually an empty room was provided for individual testing. Each child was tested for four half-hour sessions. The sequence of test administration was the same for all children. With the exception of Progressive Matrices and Figure Copying, all tests were given individually.

a Raven’s Colored Progressive Matrices Raven’s Colored Progressive Matrices is a widely used test devised as a culture-fair measure of reasoning ability. The test consists of 36 tasks increasing in difficulty. The tasks are visually presented as a sequence of patterns with one piece omitted. The child is required to complete the pattern by selecting the appropriate match from a series of given alternatives. It is a commonly used instrument in cross-cultural comparisons and serves as Jensen’s (1970) criterion measure of Level I1 abilities. According to Luria (1966), the tasks require simultaneous synthesis for their solution, Luria’s general finding is that patients suffering from lesions of the occipitoparietal divisions of the cortex manifest noticeable shortcomings in their performance on this test. Such patients concentrate on only one aspect of the stimulus array and are unable to integrate the necessary spatial relationships to effect the correct response. b. Figure Copying Test This test was developed by Ilg and Ames (1964) as a measure of developmental readiness. The child is required to copy 10 geometrical forms increasing in level of difficulty. The copying requirement removes any dependence on memory from the test, The test appears to be a measure of cognitive development rather than perceptual motor ability (Jensen & Rohwer, 1970). Luria (1966) believes that asking a person to copy a series of geometrical figures possessing a certain spatial orientation represents one of the simplest forms of simultaneous synthesis.

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21 1

c. Memory for Designs This task was developed by Graham and Kendall (1960) primarily as an instrument to detect minimal brain damage. The child is presented visually with a series of 15 different designs. Each figure is presented individually to the child for a 5-second viewing interval. Subsequently, the child reproduces the design from memory on a blank 8-by1I-inch sheet of paper. Responses are scored for errors. It has been used to distinguish normals from retardates (Ritchie & Bottler, 1964) and among normals, the slow from the average reader. In the present study it was employed solely as a memory task for designs. This task loads highly on the simultaneous factor in all analyses @as et ul. ,1975). d. Auditory Serial Recall In this task subjects were aurally presented with a series of 4word sequences. Immediately following each presentation, the child was required to recall verbally the sequence in the given order. Responses are scored for their serial correctness only for Serial Recall, and for items correctly recalled regardless of position for Free Recall. The task can be classified as a Level I measure and, projecting from Das’ (1972, 1973a, 1973b) fmdings, it will serve as an index of successive synthesis (aural presentation minimizes the possibility of arranging elements into a simultaneous spatial array).

e. VisualShort-Tern Memory The task was adopted from a test originally devised by E. Howarth and J. Browne of the University of Alberta. In this successive task, a series of 5-item grids are visually presented by a slide projector for recall. Each matrix is viewed for 5 seconds, followed by a 2-second filer task of color naming to preclude rehearsal. When the stimuli are numbers, the child is required to reproduce the digits on an empty grid immediately following the fder task. Responses are scored for free and serial position. The procedure was slightly modified for testing in Orissa in that it was not possible to give the ffier task (which usually required a slide projectorinterval timer hookup). The stimulus matrices were presented on separate cards; subjects waited for 2-3 seconds before they were allowed to put down their answers. The slide projector could not be used in many schools because the buildings had no electricity.

f: D&itSp~-FonVmd The tests were abstracted directly from the Wechsler Scale for Children. Directions and scoring followed the procedure proposed by the test manual. The digit series were presented by means of a cassette tape recorder. J e m n (1970) singles it out as a good test of Level I ability; it usually loads on the successive factor.

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g. CrOssModal Coding

The task was developed by Birch and Belmont (1964) as a measure of auditory-visual integration and has been shown to discriminate between children of high and low reading ability. The test bears a significant general relationship to IQ, suggesting that t h i s kind of intersensory integration may be one of the processes underlying adaptive or intelligent behavior. The task samples the ability to integrate and compare a temporally structured set of auditory stimuli with spatially distributed visual stimuli. Specifically, the child listens to sound patterns and is subsequently required to visually identify the auditory set from three simultaneously presented dot patterns. Factor loadings for this test are sometimes split between the simultaneousand the successive factors.

h. Word Reading and ColorNaming These tasks employ the Stroop (1935) charts. In the Word Chart, the names of four primary colors (red, green, yellow, and blue) are capitalized in black letters and occur 10 times in random order. The child is instructed to perform the task as quickly as possible and is timed for reading the 40 words. In the color-naming variant, colored strips replace the written word. These tasks serve as marker tests for the speed factor. D. Some Hypotheses

The primary objective of the present investigation is to explore the relation between malnutrition (as indexed by stunted growth) and cognitive competence. There are two secondary objectives: One is to examine the difference between high- and low-caste children in their performance in cognitive tasks. The other is to assess the effect of urban versus rural residence of the children on test performance. Even though the study is an exploratory one, some anticipations of the outcomes are possible. 1. Height is an impure measure of malnutrition. As mentioned in the review, it is jointly determined by several factors, only one of which is severe malnutrition in early childhood. In past investigations, notably by Cravioto, children divided on height have sometimes shown differences in cross-modal coding (Cravioto & Debcardie, 1975). It is hypothesized that the tall subjects will be superior to short ones in some of the cognitive tests. 2. Previous research (Das, 1973a; Das, Jachuck, &Panda, 1970; Panda & Das, 1970) has sometimes indicated that the Brahmin (highcaste) children do better than Harijan (low caste) children in cognitive tasks. However, this has not been always confirmed. One reason is the use of different cognitive tasks in the different studies. The other factor may be the urban residence of the children. In one case we have compared a group of Brahmin children from orthodox villages

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with a group from the cities (Das & Singha, 1975) of Orissa and noticed a consistent superiority of the city children’s performance in several cognitive tests. The differences, however, were not statistically signifcant. It is hypothesized that the high-caste children will perform better on the cognitive tasks than the low-caste children when both groups live in the villages. 3. If urban children have a greater amount of stimulation than rural children, an urban versus rural difference will be noticed when we control for caste and economic status. The varieties of experiences in urban settings are likely to offset some of the disadvantages of belonging to the low caste, which may be responsible for the inconsistent results of comparisons of urban children from low and high castes. In the rural area, the lower class child is much more at the mercy of his home environment; the outside environment is not intellectually stimulating. It is hypothesized that among the children from low caste and low economic class, those who live and go to school in the town are superior to those living in the village and attending village schools.

E. Results Descriptive statistics giving means, standard deviations, and correlations were computed for the samples. Means and standard deviations are presented in Table 111. The intercorrelations between the tests were later used for factor analysis. Of some importance, initially, are the correlations between parents’ and child‘s height. The average r between father’s and child’s height was .02 and r between mother’s and child’s was .24; neither was significant. Cravioto and DeLicardie had also found that among the malnourished population, the heights of parents and their children do not correlate significantly. If malnutrition were ruled out, the correlation between the average height of the two parents and that of the child should be S O . Because the r for the present sample was not significant, it was not necessary to partial out the effect parental height might have on the child’s height for subsequent analyses. The next set of computations was the analyses of variance (ANOVA). Comparisons between short and tall groups of the two castes, and the urban versus rural samples were called for in order to verify the hypotheses of the present study. Essentially two analyses of variance were considered to be adequate for our purposes: (1) A 2 X 2 ANOVA involving the two castes, and within each, the short and tall groups, and (2) a similar ANOVA for urban versus rural residence and height, within the low-caste group. It was observed (see Table N)that the Brahmin (high caste) boys performed significantly better than the Harijan (low caste) boys in Visual Short-Term Memory (STM), Serial Recall, Digit Span, Cross-Modal Coding, and Word Reading. Usually, for Canadian samples, the first three tests load on the successive

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TABLE I11 PERFORMANCE OF TALL AND SHORT BOYS ON COGNITIVE TESTSa

Rural low caste

Urban low caste

Rural high caste

Tall

Short

Tall

Short

Tall

Short

18.05 5.45

16.67 5.43

16.12 5.16

14.88 4.12

18.37 6.29

17.05 5.54

11.21 2.01

11.12 2.24

15.58 4.69

12.65 2.84

11.05 2.30

10.85 1.92

8.25 5.54

9.35 6.07

9.15 6.15

8.93 4.91

9.17 5.79

10.78 6.41

5.48 1.93

5.25 1.63

5.68 1.83

5.55 1.53

6.50 2.08

5.85 1.96

51.40 11.33

51.95 9.98

54.65 11.41

48.22 12.99

56.33 9.43

55.10 9.69

Digit Span M SD

4.43 .90

4.58 .84

4.90 .88

4.53 .88

5.02 .88

5.02 .I6

Visual STM M SD

84.48 14.90

51.95 9.98

84.98 16.58

84.12 16.03

91.87 14.32

92.91 10.61

42.31 26.05

39.68 24.61

43.01 26.29

45.21 31.18

33.13 16.06

34.11 14.32

11.12 34.01

14.45 69.59

62.33 24.40

73.03 34.08

69.33 25.14

14.10 32.81

Tests Progressive Matrices

M SD

Figure Copying M SD Memory for Designs (errors) M

SD Cross-Modal Coding M SD Serial Recall M SD

Word Reading (latency)

M SD Color Naming (latency) M

SD ON

= 60 in each group.

215

MALNUTRITION AND COGNITIVE FUNCTIONING

TABLE IV 2 (HEIGHTS) x

SUMMARY OF 2 (CASTES) ANALYSES OF

VARIANCE^

F ratios Tests

Caste main effect

Height main effect

Interaction

Progressive Matrices Figure Copying Memory for Designs Cross Modal Coding Serial Recall Digit Span Visual STM Word Reading Color Naming

<1 <1 2.28 10.62' 9.39' 21.12d 15.62d 6.76' <1

3.32' <1 3.05b 3.17'

<1 <1 <1 <1

<1 <1 <1 <1

<1 <1 <1 <1

factor; the last two, sometimes, also load on that factor. But the picture is not the same for the present samples from Orissa; it will be discussed later along with the results of factor analyses. Tall boys did better than the short in the following tests although the F ratios were of borderline significance (.lo): Progressive Matrices, Memory for Designs, and CrossModal Coding. All the three tests usually load on the simultaneous factor. In the second ANOVA, the low-caste tall were better than the short in their scores on Progressive Matrices and Figure Copying. In addition to these two simultaneous tests, in the urban sample, they were also better in Serial Recall. The urban boys had better mean scores on Figure Copying irrespective of height, and on Digit Span only in the tall group. Curiously, the rural were better than the urban in Progressive Matrices. The above analyses were based on data collected by one experimenter. We had some additional data gathered by another experimenter in urban and rural areas adjacent to those covered by the first experimenter. These were added and an analysis of variance was performed as summarized in Table V. Note that the groups have unequal numbers of subjects. The new analysis showed a significant tall/short main effect for the same three tests as the old one did-Progressive Matrices, Figure Copying, and Serial Recall. Further, in the Serial Recall test, the significant interaction term implied that the tall were better than the short in the urban sample, but the short were better in rural. In summary, taking into account the two analyses, the results clearly show that the tall boys had higher scores on Progressive Matrices and Figure Copying. In the new analysis, urban/

J. P. Das and Emma Pivato

216 TABLE V

SUMMARY OF 2 (HEIGHTS)X 2 (URBAN/RURAL) ANALYSES OF VARIANCE’

F ratios Tests Progressive Matrices Figure Copying Memory for Designs Cross-Modal Coding Serial Recall Digit Span Visual STM Word Reading Color Naming

Urbanlrural main effect

Height main effect

Interaction

<1 36-18‘ 4.95’ 2.43

3.87’ 11.97’ <1 <1 3.80 1.10 <1 <1 3.2Sd

<1 <1 <1 <1 6.70e (urban tall>rural tall) 4.93’ (urban tall>rural tall) 1.31 <1 <1

2.1Sd

3.3Sd <1 <1 4.81’

‘UnequalNs;df= 1336;bp<,OS;cp<.OO1;dp~.lO.

rural main effect was significant for Figure Copying, Memory for Designs, and Color Naming, an improvement over the old analysis. For Canadian samples, Color Naming usually loads on the speed factor whereas the other two load on the simultaneous factor. But as will be apparent from the factor analyses, their loadings cannot be so clearly interpreted for the Orissa samples. Next to be reported are the factor analyses. Principal component analyses with Varimax rotation were performed on the correlation matrix obtained in each of the six samples of subjects. One way of looking at the results is to consider whether the three factors-simultaneous, successive, and speed-were generally obtained. Another way is to sort out the tests in terms of their loadings on factors identified as simultaneous, successive, and speed. On the whole, the three factors could be recognized in four out of the six samples; the exceptions were the two rural low-caste samples. Factor analysis of rural low-caste tall data showed a speed factor, a factor which may be labeled successive-simultaneous (Serial Recall, Progressive Matrices, Digit Span, CrossModal Coding, and Visual STM loaded hierarchically in that order), and an unnamed factor on which Figure Copying, Visual STM,and Word Reading speed loaded in that order. The rural low-caste short sample did not have any factor which could be named clearly. The first factor was a combination of speed and successive tests (marker test was Word Reading); Factor 2 had its two highest loadings on Progressive Matrices and CrossModal Coding, but substantial loading on Digit Span, followed by Memory for Design and Serial Recall. Factor 3 had its only high loading on Figure Copying. In terms of their factor loadings, the speed tests and successive tests were more stable than the simultaneous tests. Usually, in Canadian samples, Word

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217

Reading and Color Naming load on a speed factor; these tests given to the samples in Orissa behaved in the same manner. Likewise of the three successive tests (Serial Recall, Digit Span, and Visual STM), Visual STM had some loadings on the speed factor although it had the same high loadings as the other two on the successive factor. The four simultaneous tests were the Progressive Matrices, Figure Copying, Memory for Designs, and Cross-Modal Coding. Of these, Figure Copying was the least consonant, often loading highly on a separate factor. Progressive Matrices loaded most frequently on the simultaneous factor. Patterns of information processing are indicated by the factor analyses of our battery of tests @as, 1973a). If so, did the malnourished groups (short) differ generally from the relatively nonmalnourished (tall) groups? Did they show characteristic patterns? As far as the present results are concerned, they did not. The short group did not differ from the tall in the manner in which it approached the tests. But since the analyses of variance indicated that on some of the tests it scored lower than the tall, the difference can be best described as one of level or degree of competence. F. Discussion

The first part of the discussion will be devoted to the hypotheses. In the second part, the general implications of the present research along with those of past studies will be discussed. As far as the cumulative effect of malnutrition is concerned, a tallshort difference will provide the critical evidence. It was hypothesized that the tall group will be superior to the short in some cognitive tests; it was not possible to predict in which particular group of tests this would be noticed. The results of the analyses of variance support the hypothesis. The performance of the tall group was clearly better than that of the short for Figure Copying, Progressive Matrices, and Serial Recall in one analysis. The tall group’s superiority approached statistical significance in the other analysis for three tests-Progressive Matrices, Memory for Designs, and Cross-Modal Coding. The last test, Cross-Modal Coding, is of special importance in Birch and Cravioto’s research on malnutrition (Cravioto, Gaona & Birch, 1967) in that the test indicated a relatively poor “auditory-visual integration’’ in short children. In the present study on Orissa children, the Cross-Modal Coding was not as strong a discriminator as some of the other tests (Progressive Matrices, Figure Copying, and Serial Recall). Is it possible to describe the superiority of tall over the short as one of simultaneous processing? Except for Serial Recall, all the other tests on which the tall group was better belonged to the simultaneous category. However, in the present study, the factor loadings of these tests in terms of the dual processes of simultaneous and successive were not as clear-cut as those obtained from Canadian samples.

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J. P. Das and Emma pivat0

The second hypothesis predicted that irrespective of height, the high-caste children will excel the low caste in most of the cognitive tests. This was indeed true: The Brahmins were superior to the Harijans in the three successive tests (Serial Recall, Visual STM, Digit Span), and in Cross-Modal Coding (split loadings on simultaneous and successive) and Word Reading (speed). All children were from the rural areas. What do the caste differences reflect? Subcultural differences in the microenvironments of the homes of the two castes are apparent; their “ways of life” are obviously different. But how these result in a higher cognitive competence for the Brahmin caste is not clear. Research into the factors in the microenvironment and their mode of influence on cognitive development of children from the two castes has not been carried out. The third hypothesis predicted that the urban group will perform better than the rural group in some of the tests. They did so in Figure Copying and Memory for Designs, which are traditionally simultaneous tests, and on Color Naming, which is a speed test, Additionally, tall urban boys were superior to tall rural boys in Digit Span. Owing to the fact that the loadings of Figure Copying and Memory for Designs are not exclusively on the simultaneous factor, it will be correct to say that urban-rural differences exist in all three processing categories. Generally, then, the results from the research in Orissa add to the existing pool of evidence showing the deleterious effects of malnutrition and its associated ecological factors on cognitive competence. In particular, it is reaffirmed that stunted growth can be associated with some amount of cognitive incompetence. It should be clearly stated that stunted growth cannot be a causative variable for poor performance in some mental tasks; the present study was not designed to establish a causative relation. Indeed, it may be extremely difficult to design one as explained in the review section of this chapter: It is impossible to separate the influence of malnutrition from factors in the macro- and microenvironments where malnutrition is widespread. Both short stature and poor performance could be the product of the ecological setting of malnourished populations. Previous research had shown that I@ were depressed in malnourished children identified either through a history of severe clinical malnutrition or on the basis of height (Cravioto & DeLicardie, 1975; McLaren, Yaktin, Kanawati, Sabbagh, & Kadi, 1973; Richardson, Birch, & Hertzig, 1973). The present results point out what specific processes are adversely affected. These are simultaneous, and to a lesser extent successive, “Speed” as defined in our battery of tests does not differentiate between short and tall children. Malnutrition also does not affect performance in sensorimotor tasks of Piagetian Scales as Dasen (1973) seems to have discovered among the Baoule children of Africa. The difference seems to lie in complex mental processes. Returning to the issue of isolating the effects of malnutrition from other associated conditions, the consensus appears to be that such attempts will be

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219

counterproductive. As Tizard (1975) remarked,". . .it is not any longer very profitable to attempt to determine whether malnutrition makes a specific and unique contribution to later retardation. . . . We know enough already to say that early nutritional status is a significant factor influencing later development. A reasonable approach to the relation between malnutrition and mental function is to view it in the context of cultural disadvantage. Socioeconomic status and other subcultural differences independent of economic prosperity contribute to competence in learning and thinking (Bresnahan & Shapiro, 1973; Das, 1973a; Feshbach, 1973). The Orissa study is precisely one on disadvantaged children; but among them are the less and more disadvantaged depending on caste and urban or rural residence. Since all children are from low socioeconomic class, economic disadvantage is not an independent variable here. Birth into the high or low caste becomes significant as an independent variable only when one can demonstrate distinct subcultures associated with the homes in each caste, and if the subculture influences cognitive competence directly or indirectly. Obviously, the influences exist and cause the high-caste children to excel the low castes in rural areas where the stimulation provided by the family becomes the major sustenance for the cognitive growth of the child. The urban subculture provides a variety of experience for the young child and it is not surprising that the urban children were superior to the rural on some of the tests. Short stature can be understood as a dependent variable along with the poor performance on the cognitive task. The conditions which inhibit growth in chronically undernourished families may be also responsible for poor performance. Cravioto and DeLicardie's prospective study in a Mexican village, as mentioned earlier in the review, should come up with several of these conditions. One of these has been identified as the mother's desire to know and accept new information. Among the disadvantaged families, some other factors have been recognized: mother-child interactions mess & Shipman, 1968), quality of mothering (Gray, 1970), and parental expectancy regarding the child's education (Das, 1973a). Apart from the conditions inherent in the family, the child's attention, motivation, and strategy during problem solving (Bresnahan & Shapiro, 1973) directly influence his task performance. Does malnutrition further depress cognitive functions of culturally disadvantaged children? The answer to this question is of some importance. Suppose PCM does not have an additional effect over and beyond the effect of cultural disadvantage. Then the biomedical evidence linking malnutrition to damage to the structures of the brain needs to be reexamined. A crucial study which may answer the above question should have two samples of children for comparison-one which is culturally disadvantaged and has survived severe clinical malnutrition and the other which is equally disadvantaged but without such a clinical history. The two groups should have comparable family environments. In Colombo, we have just completed a study of this sort as mentioned in the review section. The family and biographical histories of the malnourished and control

220

J. R Das and Emma Pivato

children are found to be quite similar; on such variables as father and mother’s education and the quality of the home environment as measured by Richardson’s (1972) questions, the two groups are comparable. We are awaiting the analysis of the cognitive performance data from the Colombo study. Whatever may be the outcome of the future studies on the effect of malnutrition which invariably occurs in culturally disadvantaged homes, remedial measures to improve the children’s cognitive functions should be developed and used. Even if the extant differences between the malnourished and the control children were partly due to hereditary factors, remedial programs for the preschool children can compensate for their lag in cognitive functioning. The cause of intellectual differences does not have any implication for educability.

IV. SUMMARY

In the first part of the chapter, the relationship between PCM and mental development was reviewed. The conclusions were: (1) effects of PCM are inextricably blended with the effects of social-cultural disadvantage; (2) the survivors of marasmus and kwashiorkor demonstrate the adverse effects of PCM in their cognitive functioning during childhood; and (3) PCM of less severe magnitude may affect school performance. Three major designs for examining the effect of malnutrition on cognitive functions were presented with illustrations from the author’s (Das) projects in Colombo, Sri Lanka, and in Orissa, India. A preliminary report of the results of the Orissa study in which short stature was used as an index of malnutrition was presented in the second part of the chapter. The design of that study is novel in that economic status was uniformly low for the short and tall children, but “cultural” disadvantage was varied by taking the children from high and low castes and from urban and rural areas. Results supported poor cognitive functioning as revealed by some (not all) of the tests in short children when compared with the tall. The cultural variables significantly influenced test scores-high-caste children did better than the low caste, and urban children did better than rural children in some tests. Whether or not malnutrition adds to the deleterious effect of economic and cultural disadvantage could not be adequately answered by the design of the Orissa study. An answer may be oqtained from the Colombo study in which the survivors from severe PCM seem to have the same unstimulating home environment as those of control children. ACKNOWLEDGMENT The Orissa study was a part of the project on the effect of malnutrition supported by Canada Council Grant $73-0056 to J. P. Daa Research assistants for the project were Tapati Dutta, P. S. Singha, and A. Paul; their help is gratefully acknowledged.

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REFERENCES Beargie, R. A., James, V. L., & Greene, J. W. Growth and development of small-fordate newborns. Pediatric Clinics of North America, 1970,17,159. Birch, H. G., & Belmont, L. Auditory-visual integration in normal and retarded reader. American Journal of Orthopsychiatry, 1964,36,852-861. Birch, H. G., & Gussow, J. D. Disadvantaged children, health, and school failure. New York: Harcourt, 1970. Bresnahan, J. L., & Shapiro, M. M. Learning strategies in children from different socioeconomic levels. In H. W. Reese (Ed.), Advances in child development and behavior. VoL 7. New York: Academic Press, 1973. Pp. 32-81. Champakam, S., Srikantia, S. G., & Gopalan, C. Kwashiorkor and mental development. American Journal of Clinical Nutrition, 1968,21,844-852. Chandra, R. K. Antibody formation in first and second generation offspring of nutritionally deprived rats. Science, 1975,190,289-290. Chase, H. P., & Martin, H. P. Undernutrition and child development. New England Journal of Medicine, 1970,282, 17. Chow, B. F., Blackwell, R. Q., & Sherwin, R. W. Nutrition and development. Borden Review of Num'tional Research, 1968,29,3. Co Tui. Review: Fundamentals of clinical proteinology. Journal of Clinical Nutrition, 1953, 1,232-246.

Coursin, D. B. Effects of undernutrition on central nervous system. Nutrition Reviews, 1965,23,3.

Cravioto, J., & DeLicardie, E. Nutrition and mental subnormality.Paper presented at the Third Far East Symposium on Nutrition, Manila, February 1967. Cravioto, J., Gaona, C. E., & Birch, H. G. Early malnutrition and auditory-visual integration in school age children. Journal of Special Education, 1967,2,75-82. Cravioto, J., & DeLicardie, E. Environmental correlates of severe clinical malnutrition and language development in survivors from kwashiorkor or marasmus. In Nutrithn, the nervous system and behavior. Washington, D.C.: Pan American Health Organization, 1972.

Cravioto, J., & DeLicardie, E. Environmental and nutritional deprivation in children with learning disabilities. In W. M. Cruickshank & D. P. Hallahan (Eds.), Perceptual and learning disabilities in children Syracuse: Syracuse University Press, 1975. Pp. 3-104. Das, J. P. Patterns of cognitive ability in nonretarded and retarded children. American Journal of Mental Deficiency, 1972, 7 7 , 6 1 2 . Das, J. P. Cultural deprivation and cognitive competence. In N. R. Ellis (Ed.), International review of research in mental retardation. VoL 6. New York: Academic Press, 1973. (a) Das, J. P. Structure of cognitive abilities: Evidence for simultaneous and successive process ing. Journal of Educational Psychology, 1973,65,103-108. (b) Das, J. P., Jachuck, K., & Panda, T. P. Caste, cultural deprivation and cognitive growth. In H. C. Haywood (Ed.), Social-cultural aspects of mental retardation New York: Apple ton, 1970. Das, J. P., Kirby, J., & Jarman, R. Simultaneous and successive syntheses: An alternative model for cognitive abilities. Psychological Bulletin, 1975,82,87-103. Das, I. P., & Molloy, G. N. Varieties of simultaneous and successive processing in children. Journal of Educational Psychology, 1975,67,213-220. Das, J. P.,& Singha, P. S. Caste, class and cognitive competence. Indian Educational Review, 1975, 10,1-18.

Dasen, P. R. Preliminary study of sensori-motor development in Baoulb children. Early child Development and Care, 1973,2,345-354.

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Deutsch, M.,& associates. The disadvantaged child. New York: Basic Books, 1967. Dobbing, J. The later development of the brain and its vulnerability. In J. P. Davis & J. Dobbing (Edr), Scientific foundation o f paediatrics London: Heinemann Medical Books, 1974. Edozien, J. C., & Obad, M. E. Protein and amino acid metabolism in kwashiorkor. Clinical Science, 1965,29,1-24. Eichenwald, H. F., & Fry, P. C. Nutrition and learning. Science, 1969, 163,644-648. Feshbach, N. D. Crowcultural studies of teaching styles in four-year olds and their mothers. In A. D. Pick (Ed.), Minnesota symposium on child psychology. VoL 7. Minneapolis: University of Minnesota Press, 1973. Pp. 87-1 16. Cam, S. M.Malnutrition and skeletal development in the preschool child. Proceedings o f t h e International Conference on the Prevention of Malnutrition in the Preschool Child, 1964. Washington, D.C. Pp. 7 4 8 4 . Garrow, J. S., & Pike, M. C. The long-term prognosis of severe infantile malnutrition. Lancet, 1967, i, 1-4. Gottfried, A. W. Intellectual consequencesof perinatal anoxia. Psychological Bulletin, 1973, 80,231-242.

Graham, F. K., & Kendall, B. S. Memory-for-designs test: Revised general manual. Percep hrol and Motor Skills, 1960,11(Monogr. Suppl. 2-7), 147-188. Gray, S. W.Intervention with mothers and young children: The focal endeavor of a research and training program. In H. C. Haywood (Ed.), Social cultural aspects of mental retardation. New York: Appleton, 1970. Pp. 508-519. Grimble, R. F., & Whitehead, R. G.The effect of an oral glucose load on serum free amino acid concentration in children before and after treatment for kwashiorkor. British Journal ofNutrition, 1971,25,253. Grotberg, E. H. Neurological aspects of learning disabilities: A case for the disadvantaged. Journal of Learning Dhbilities, 1970,3,25-31. Hertzig, M. E., Birch, H. G., Richardson, S. A, & Tizard, J. Intellectual levels of school children severely malnourished during the first two years of life. Pediatrics, 1972,49, 814-824.

Hess, R. D., & Shipman, V. C. M a t e d influences upon early learning: The cognitive environments of urban preschool children. In R. D. Hess & R. M. Bear (Eds.), Early education, Chicago: Aldine, 1968. Pp. 91-104. Hopkine, K. D. Regression and the matching fallacy in quasiexperimental research. Journal of Special Education, 1969,3,329-336. llg, F. L., & Ames, L. School readiness New York: Harper, 1964. Jensen, A. R. A theory of primary and secondary familial mental retardation. In N. R. Ellis (Ed.), International review of research in mental retardation VoL 4. New York: Academic Press, 1970. Pp. 33-100. Jensen, A. R., & Rohwer, W. D. An experimental analysis of learning abilities in culturally disadvantaged children. Final Report, 1970, OEO Project No. 2404, U.S. Office of Economic Opportunity. Kaplan, B. J. Malnutrition and mental deficiency. Psychological Bulletin, 1972, 78, 32 1-3 34.

Kotch, J. Proteirrcalorie malnutrition and mental retardation. Social Sciences und Medicine, 1970,4,629-644. h e g e r , R. Some long-term effects of severe malnutrition in early Life. Lancet, 1969, i, 514-517. Luria,A. R. Human brain and psychological processes New York: Harper,1966. Manocha, S . L. Malnutrition and human development. Springfield, Ill.: Thomas, 1972. McLaren, D. S., Yaktin, U. S., Kanawati, A. k,Sabbagh, S., & Kadi, Z. The subsequent

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mental and physical development of rehabilitated marasmic infants. Journal of Mental Deficiency Research, 1973,17,273-281. Monckeberg, F. The effect of malnutrition and environment on mental development. Proceedings, Western Hemisphere NumYion Congress, 1968, 11, American Medical Association, Chicago. Morrison, A. B., & Rao, M. N. Some relationships between proteins and calories. World Review of Nutrition and Dietetics, 1967,7,204-224. Munro, H. H., & Allison, J. B. (Ed$.) Mammalian protein metabolism. Vol. 1. New York: Academic Press, 1964. Panda, K. C.,& Das, J. P. Acquisition and reversal in four subcultural groups generated by caste and claw Canadian Journal of Behaviorrrl Science, 1970,2,267-273. Platt, B. S., & Stewart, R. J. C. Reversible and irreversible effects of protein-calorie malnutrition on the CNS. In G. H.Bourne (Ed.), Review of nutrirfon and dietetics VoL 13.Basel: Karger, 1971. Pollitt, E. Ecology, malnutrition and mental development. Psychosomatic Medicine, 1969,

31, 193-200. Raven, J. C. me mloured progressive matnces guide. London: Lewis, 1956. Riccuiti, H. N. Malnutrition and psychological development. Paper presented at Cornell University, 1972.In J. I. Numberger (Ed.), Biological and environmental determinants of early development. Baltimore: Williams & Wilkins, 1973,Chapter 4. Richardson, S. A. Ecology of malnutrition: Nonnutritional factors influencing intellectual and behavioral development. In Nutrition, the nervous system and behavior. Sci Publ. No. 251.Washlagton, D.C.: Pan American Health Organization, 1972. Richardson, S. A., Birch, H. G., & Hertzig, M. E. School performance of children who were Jeverely malnourished in infancy, American Journal of Mental Deflciency. 1973, 77,

623-632. Ritchie, J., & Bottler, A. Performance of retardates on the Memory-for-Designs Test. Journal of Clinical Psychology, 1964,20,108-110. Sanstead, H. H., Carter, J. P., House, F. R., MSoMel, F.,Horton, K. G., & Vander Zwaag, R. Nutritional deficiencies in disadvantaged preschool children. American Journal of Diseasesof children, 1971,121,455463. Scrimshaw, N. S., Taylor, C. 0.. & Gordon, J. E. Interactions of nutrition and infection. WHOMonograph Series, 1968,No. 57. Stanley, J. C. Problems in equating groups in mental retardation research. Journal of Special Education, 1967,11,241-256. Stewart, R. J. C. Maternal diet and prenatal death. Proceedings of the Royal Society of Medicine, 1968,61,1292-1294. Stroop, J. R. Studies of interference in seM verbal reaction& Journal of Experimental Psychology, 1935,18,643-661. Tizard, J. Nutrition and human development. In D. A. A. Primrose (Ed.), Proceedings of the Third Congress of the International Association for the Scientiflc Study of Mental Deficiency. Warsaw: Polish Medical Publishers, 1975. Tripathy, K. E., Gonzalez, F., & Lotero, H. Effects of ascaris infection on human nutrition. American Journal of i?opical Medicine and Hygiene, 1971,20,212-218. Warren, N. Malnutrition and mental developmemt. Psychologicnl Bulletin, 1973, 80,

324-328. Winick, M., & ROW, P. Head circumference and cellular growth of the brain in normal and marasmic children. Journal of Pediktrics, 1969,74,774-778.

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Research on Efficacy of Special Education for the Mentally Retarded MELVIN E. KAUFMAN AND PAUL A. ALBERT0 GEORGIA STATE UNIVERSITY, ATLANTA, GEORGIA

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I. Introduction 11. ResearchReview A. Studies of the Educable Mentally Retarded B. Studies of the Trainable Mentally Retarded 111. An Analysis of the Experimental Control of Variables in Efficacy Research A. Randomness B. Control of Classroom and Instructional Variables C. Appropriateness of Measuring Devices IV. The Future of Efficacy Research in Special Education How Can Future Efficacy Studies Be Improved? References

225 226 226 241 243 243 245 249 251

251 253

1. INTRODUCTION

A review of the studies of special educational intervention for the educable

(EMR) and trainable (TMR) mentally retarded children is presented in this chapter. A fundamental problem in this area is that the reviewer must evaluate complex field-based studies where often several independent variables have not been adequately controlled, and the dependent variables have not always been clearly defined. Yet it remains extremely important to review and assess past attempts to study efficacy, because of the necessity to determine how much credence we can place on specific research efforts and what directions appear to be constructive in increasing the meaningfulness of future research and educational planning in this area. Included herein are published studies and Government project reports as well 225

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as selected unpublished doctoral dissertations. The chapter is organized fust to present descriptions, general results, and conclusions of the studies. Since reviewers such as Cegelka and Tyler (1970) have analyzed efficacy studies in terms of academic and social development, it is necessary to view the studies from a chronological perspective in order to assess methodological changes that have occurred over the past 40 years. Included are studies that span the period from 1936 to the present time. Second, there is a section dealing with some of the key experimental variables which need to be considered in attempting to assess the methodological soundness of the studies. Finally, there is an attempt to suggest some future directions of research on efficacy. II. RESEARCH REVIEW

A. Studies of the Educable Mentally R m r d d Pertsch (1936) attempted to investigate the educational achievement and personal adjustment of educable mentally retarded (EMR)children within regular and special classes in the New York City School System. There were 278 subjects matched for CAYMA, IQ, sex, and race. Subjects were tested for educational achievement, mechanical aptitudes, and personal adjustment. On all but mechanid aptitudes, children in the regular classes were superior. The groups were retested after an additional &month period. Once again the children in the regular classes were found to be superior in educational achievement (reading comprehension, arithmetic computation, and arithmetic reasoning), and in personal adjustment. Cowen (1938) reviewed Pertsch’s (1936) study and found substantial methodological errors in that work. Among the many problems was poor matching of segregated and integrated groups. At the onset of the study, the groups integrated with regular classes were substantially ahead of the groups segregated in special classes on a majority of the independent variables which included the tests of both academic and social variables. Further, Cowen presented data which compared mean percentage gains in test scores during the period of placement of the two groups. When calculated in terms of mean percentage gains, the Pertsch results provided evidence directly contradictory to his conclusions, i.e., rather than showing superiority for the group integrated in regular classes, the results suggested the greatest percentage gains in academics were made by the children segregated into special classes. Johnson (1950) investigated the social position of mentally handicapped (MH) students in regular classes and compared such children with “typical non-retarded subjects” in the same classes. The study was conducted in two communities in which there were no special classes for the mentally retarded. A total of 25 classes, each with one or more MH children, were selected. There were

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five classes at each grade level (Grades 1-5). The experimental group members were selected on the basis of teacher’s recommendations, low academic ability as determined by the Progressive Achievement Tests, low scores on a group test of intelligence, and an IQ of 69 or below on the Stanford-Binet. A comparative description of the mentally handicapped yV = 39) and typical group (N= 621) included the following: (1) there was a proportionately larger number of MH boys in the classes; (2) the MH group was significantly older; (3) the mean IQ on the California Test of Mental Maturity (short form) for the MH group was significantly lower than the mean of the typical group; (4) the mean combined reading and arithmetic age of the MH group was significantly lower. However, differences at the different grade levels of social ages were not significantly lower. Sociometric questionnaires were developed and administered to every child in the study. Responses to the questionnaires indicated that the MH children were less accepted and more rejected than the typical children. The acceptance scores increased as mean IQs of established subgroups (low MH, high MH, borderline, etc.) increased. An important exception to this general trend was that the highest percentage of rejectees was found for the upper MH group. It should be noted parenthetically that Johnson’s N for the upper MH group was 32 which represented the majority of the experimental group, with the lower MH group consisting of only 7 subjects. The majority of reasons given for rejection of the MH group by peers were unacceptable behaviors such as bullying, fighting, misbehaving, showing off, swearing, lying, and cheating, and an apparent inability or desire to conform to group standards of behavior. Lapp (1957) conducted a study to investigate the comparative social adjustment of an EMR population in two class settings. Specifically, she set out to evaluate social acceptance and rejection among peers in special classes and in regular classes, and whether special class placement made a difference in the social position of EMR children. The study made use of the one EMR class and nine regular classes ranging from third to sixth grades in a single elementary school in suburban Cleveland. The special class had 16 children (CA 7-14 years), all of whom had been referred by a local guidance council. Twelve of the children spent some time each day in regular classes (physical education, music, art, social studies, and/or science). An effort was made to place the special class students in regular classes with children of equivalent CA and physical development, and with teachers who “could understand their adjustment needs.” In order to determine social position, Lapp administered the sociometric questionnaire developed by Johnson (1950). The interviews were conducted in the spring of two consecutive years. The author concludes that: (1) acceptance scores of the children kept within the special class were significantly lower than those who were integrated into the regular classes, whereas rejection scores did

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not differ between groups; (2)the integrated children were not sought out individually as were the other children in the regular class; (3) the low scores of the integrated children, as compared to the nonretarded children, may indicate they were more passive than active in the regular class setting; (4) the integrated EMRs were not overtly rejected; ( 5 ) the EMRs in the special class appeared to be more accepted and more rejected than their peers who were integrated into the regular classes. Elenbogen (1957) sought to compare the academic and social adjustment of two groups of EMR children in the Chicago public schools. One group spent the last 2 years of their education program in special classes; the other remained in regular classes. The groups were matched on CA (mean of 13.46 years for both groups), sex, IQ, and school district. Academic achievement in reading and arithmetic was measured by the Stanford Achievement Test. School adjustment was evaluated by rating scales and interview questions, The rating scales, completed by the classroom teacher, included classroom work, behavior, adjustment to other children, and social participation. The personal interviews dealt with vocational aspirations, earning responsibilities, leisure time activities, friends, and attitudes toward school. The results on measures of reading and arithmetic indicated significantly higher mean scores for subjects without special education training in paragraph meaning, word meaning, and arithmetic computation. The rating scales indicated significant differences in favor of the special education children who exhibited more realistic vocational aspirations, a greater percentage of after school jobs with higher earnings, a larger number of friends, more participation in after school activities, and positive attitudes toward school. Baldwin’s (1958) study explored the following questions: (1) To what extent were the EMR children in regular grades of the public school accepted socially? (2)What was the social position of the children of different levels of mental retardation, CA, public school grades, and socioeconomic status? (3) What desirable or undesirable characteristics seem to be related to degree of social acceptance of the mentally retarded child? Baldwin’s sample population consisted of 572 normal children and 31 mentally retarded children (IQ range 50-74) in 22 fourth-, fifth-, and sixth-grade classes in ten different elementary schools in a large public school system. The data for the study were collected from the office of the Director of Special Education, principals, classroom teachers, the child’s cumulative folder, and interviews with one group of fifth-grade nonretarded children. Two sociometric tests (The Ohio Social Acceptance Scale and the Ohio Social Recognition Scale) were given by the classroom teacher to each child in her class. The results on the Ohio Social Acceptance Scale indicated that the degree of social acceptance of the EMR children in the regular grade was significantly lower than that of the nonretarded children. The difference between the social acceptance scores of the EMR children in groups based on level of retardation, sex, CA, and grade level

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was not significant. The presence of other EMR children within the same classroom did not appear to be related to the social acceptance scores. The results on the Ohio Social Recognition Scale indicated that the number of desirable characteristic scores given to the EMR students was significantly less than the number given to the nonretarded students. In addition, the difference in undesirable characteristics attributed to the EM% was significantly greater. During the interviews with all of the teachers and pupils, the investigator reported being impressed by the fact that the antisocial activity of the EMR children seemed to be the behavior that both groups resented. Porter and Milazzo (1958) conducted a follow-up study on retarded adults who had attended special and regular classes. They investigated social competence and economic efficiency. The 24 subjects were a minimum of 18 years old (mean CA 21.5 years) and matched IQ (mean of 63) and years in class. The 12 special class subjects had attended the Laboratory School of Indiana State Teachers College. The 12 regular placement subjects were selected from case histories of outpatients at the Special Education Clinic of Indiana State Teachers College and had attended classes in the Terre Haute City Schools. Data were collected by interviews with the subjects and their parents, friends, neighbors, and employers. Social competence was defined as frequency of change of residence, home conditions, conformity to laws of society, church attendance, and marital status. The regular education group were found to have a greater tendency to move, and to move to less desirable living conditions. Home conditions were rated slightly higher for the special class group. Also, whereas there were no arrests among the special class group, 33% of the regular class group had been arrested. The special class group attended church with somewhat greater frequency and the number of marriages was about equal. Economic efficiency was defined in terms of employment variables. Of former special class students, 9 had full-time employment, 2 parttime, and 1 was unemployed. Of former regular class students, 2 had full-time employment, 2 parttime, and 8 were unemployed. All the jobs held by those employed were unskilled or semiskilled. Porter and Milazzo reported that the employers said “schools should be concerned with the development of social skills,” as the employers could do the job training. The employers regarded the students’ major working strengths to be their ability to persist on the job, dependability, honesty, and getting along with their fellow workers. In their conclusion, Porter and Milazzo indicated the special class group tended to conform more to social standards than nonretarded subjects and showed greater frequency of employment. Blatt (1958) was interested in differences in physical development, personality characteristics, and academic status between EMR children in segregated special classes and those in regular classes. He selected 125 EMR students from

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two Pennsylvania counties, chosen because of their equivalent socioeconomic characteristics and sample availability. Ofthe 125 sample population, 75 were in special classes. These 75 subjects were selected on three bases: (1) completing at least 2 years in the elementary special class; (2) CA range of 8-6 to 16-0 years; (3) diagnosis of EMR by a certified psychometrician using an individual intelligence test, The 50 remaining subjects were matched for CA , IQ, MA, and sex and were selected on the following bases: (1) regular class placement; (2) never having been in a segregated special class; (3) living in a community that had no special classes; (4)diagnosis of EMR by a certified psychometrician on an individual intelligence test. In terms of physical status, no significant difference was found in number of days absent, power (measured by vertical jump), grip strength, motor ability, dental defects, height, and weight. However, when compared to age norms of average children, 25.33% of the special class group were more than 10% underweight, whereas only 10% of the regular group were more than 10% underweight. The special class children were found to have significantly more uncorrected or permanent physical defects. In terms of personality status, the students in the special class were viewed as more socially mature and emotionally stable as measured by the New York City Scales of Social Maturity and Emotional Stability. A significantly greater percent of this group held parttime jobs, and a significantly smaller percent had ever been classified as truant. Blatt found no significant differences between groups on these items: (1)delinquency and behavior records, (2)number of times having been brought before law enforcement agencies, (3) frequency of stealing in school, (4) number of exclusions from school because of behavior, (5) time in a detention home, and (6) percentage regularly attending Sunday school. Also, there were no significant differences between the groups on measures of personal and social adjustment on the California Test of Personality (CTP). However, when compared to the norms for average children, both MR groups had a greater number of problems in personal and social adjustment. Examination of academic status indicated no differences between the groups in reading, arithmetic, and language achievement on the California Achievement Test (CAT). When compared to norms for average children of equal MA, both retarded groups had greater total achievement in these three areas. In reading, the special class children improved more from one year to the next than those in the regular classes. Thurstone (1959) compared the intellectual, academic, social; and gross motor development of EMR children in regular and self-contained special classes. There were 1273 subjects with an IQ range of 50-79 and a CA range of 9-4 to 14-11 years. Evaluative instruments used were the Stanford-Binet Test of Intelligence, Stanford Achievement Test. Primary Mental Abilities Test, and a

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battery of gross motor and sociometric tests. No testing was done by class teachers. The Stanford Achievement Test was administered again after 1 year and the regular class children were significantly superior in all areas except arithmetic. The third administration, after 2 years, showed no significant differences between the gain scores. When divided into high IQ (60-79) and low IQ (50-59) groups, the low IQ group in special classes had significantly higher achievement gain scores than the low IQ group in regular classes. One exception to this general finding was that the low IQ regular students exceeded low IQ special students in arithmetic. In terms of social development it was found that in regular classes the EMRs (high as well as low IQ) were very likely to be social isolates. They did not receive as favorable ratings on personality traits as did normal students by either peers or teachers. In special classes, students seemed to be better adjusted in school and to have more friends than those in regular classes. In gross motor skills the EMRs were consistently inferior in accomplishments to normals of equal CA. Mullen and Itkin (1961) conducted a 2-year study using a sample EMR population from the Chicago public school system. A total of 140 pairs of students in special and regular classes were matched for age (CA range 7-13 years), IQ (range 50-74), sex, socioeconomic status, reading achievement, and foreign language spoken at home. Measures of educational achievement and personal adjustment were taken at the beginning of the period of study and after the fmt and second years. After the first year the regular class children had significantly greater gains in arithmetic, but on no other educational or adjustment measure. At the end of 2 years there were no significant differences between the groups on any educational measures. Personal adjustment was measured by teacher ratings and behavior checklists. Over the 2-year period the regular class group made significantly higher ratings in overall classroom adjustment. The special class group showed a significant decrease in hostility in the school environment. Johnson (1961) reported the results of a comparison of retardates in regular classes and self-contained classes. The basic hypothesis was that the personal and social adjustment and social acceptance of EMR children in self-contained classes would be superior to that of EMR children in regular classes. The experimental group was selected from school districts where all children diagnosed as being mentally handicapped were enrolled in special classes. The control group was selected from school districts where no special classes existed. “Subjective evaluation” was made to assure comparability of socioeconomic level, school facilities, and type of instruction. Concerning the educational experience, Johnson states, “The initial selection of the school system had insured that one could reasonably assume all the mentally handicapped children were enrolled in special

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classes since sufficient facilities were available and adequate survey methods were in use” [p. 171. Each group consisted of 16 matched pairs of subjects, half boys and half girls. The principal evaluative instrument used by Johnson was the Syracuse Scales of Social Relations (adapted from the CTP). The author reported that social acceptance of children in self-contained classes was significantly superior to EMRs in regular classes. No differences were found between experimental and control groups with respect to results of the CTP. Warren’s (1962) study was designed primarily to evaluate the effectiveness of EMR classes as measured by changes in achievement, intelligence, tests, and integrative ability test scores during the first year of such placement. The experimental group consisted of 24 children who had been placed in an EMR class for the first time during the 1959-60 school year. The 24 control children were eligible for EMR placement, but were retained in a regular class during the entire school year. The children were matched on sex, IQ, CA, and number of years in school. The sample was selected from six schools with EMR classes and seven schools without such classes. There was some attempt to match on socioeconomic factors using an estimate based on the occupation of the subject’s father and/or mother. A battery of tests consisting of the Stanford-Binet, Draw-A-Person, Bender Gestalt, Hunter-Pascal Concept Formation, and the CAT were administered at the beginning and end of the school year. Change scores were analyzed using nonparametric statistics. No discussion of educational programming was included. Warren concluded that there were no significant differences between the groups regarding achievement or IQ change. There were many indications that early EMR placement is superior to placement at a later date “after the child has begun to recognize his tendency to be a failure.” Evidence of early success was the only predictive feature obtained in the study. Kern and Pfaeffle (1962) evaluated the social adjustment of three groups of children each consisting of 31 EMR children placed in (1) a segregated public school for retarded, (2)segregated EMR classes in a public school, and (3)regular public school classes. The authors used the CTP to measure social adjustment of the children in the three educational settings. Noteworthy was that the regular class EMR group was on a “waiting list” to be placed in a segregated EMR class and therefore were considered matched to the segregated class group in all respects, save class placement. Yet, there may have been some differences in these two groups, since the authors point out that the EMR children in the regular classes tended to be younger and had higher IQ scores. Results indicated that the special-school children demonstrated the highest overall adjustment scores and the retardates in regular classes had the lowest overall scores on the CTP. The authors conclude that EMR children placed in

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segregated classes or in special schools show much better school adjustment than EMR children in regular classes. In a study by Meyerowitz (1962), the author reported testing two hypotheses: (1) that EMRs are more self-derogatory than nonretarded children; and (2) retarded children in regular grades are more self-derogatory than retardates in special classes. A sample of 120 EMRs and 60 normals were included in the study. Placement in regular or self-contained classes for the retarded was based upon random selection. The measuring instrument was the Illinois Index of Self-Derogation (IISD). In this test, the child is presented with 30 items, each consisting of two sentences. One of the two sentences describes “a socially undesirable ascription,” the other a “socially desirable” or “neutral ascription.” The child is asked to select the sentence which he feels is most like himself. The results support the first hypothesis, that EMRs have a significantly higher self-derogation score than nonretarded peers. The second hypothesis was not confirmed; Meyerowitz found that EMR children in regular classes obtained significantly lower self-derogation scores than those children in special classes. Stanton and Cassidy (1964) conducted two complementary investigations of the efficacy of special education. The subjects (IQ 50-75, CA 12-14 years) were selected from samplings of various school systems in Ohio to test differences in achievement and adjustment. The first study was a comparison of regular and special class children. Regular class children performed better academically (Stanford Achievement Test Scores of 2.7 for the special class and 3.1 regular class). Neither group approached the norm for average 13-year-old children (7.0),nor did they reach the expected achievement level for their MA. The authors then evaluated an additional group of residential EMRs and found the following relative performance of the three groups: The special class children performed better than the regular class children but were surpassed by the residential children on the CIT, Goldstein-Scheerer Stick Test, Raven’s Coloured Progressive Matrices, and the WISC block design. No statistical data were included in this report. Regular class children surpassed special class children on the Stanford Achievement Test and WISC coding subtest. Residential children scored lowest, special class children were highest, and regular class EMRs maintained a middle position on the Ammons Picture Vocabulary Test, Goodenough Draw-A-Man test, and the Kent E-GY. Data collected from teacher scored checklists reflected the view that regular class EMR children were functioning within their ability to learn; residential class children were functioning below their ability. Stanton and Cassidy state residential subjects “were both more keenly interested in school and more afraid to fail.” Stanton and Cassidy drew several inferences from the data collected: (1) there are differential performances within the EMR range (i.e., IQ 50-59, 70-75); (2) current practices seem to be of more overall benefit to the low (IQ

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5+59) end of the EMR population; (3) least responsive to “adjusted educational environments” are those within the 70-75 IQ range; (4)competition within the regular class raised the performance of the low IQ children but may have frustrated the high IQ children; ( 5 ) chances for greater academic performance by the higher IQ children lies in the segregated class; and (6) the accepting environment of the segregated class encourages social adjustment. Bacher (1964) selected an experimental group and a control group of 30 pupils each from among the slow learners in grades 6 through 8 attending the Ridgefield Park, New Jersey, elementary schools. A slow learner was defined as having a measured IQ of 75-95 and scoring one or more years below that expected for his CA in reading. The experimental group consisted of 15 students from each of the two slow learning groups who met the criteria for the slow learner classes but who had not been placed because of unavailable space. Test analyses were computed to measure the differences in self-concept, social adjustment, and reading growth of the two groups over 1 year. Selfconcept was measured with the student’s self-concept score on the Columbia Classroom Social Distance Scale and the student’s “I Think Score” on the Davidson-Lang Checklist of Trait Names. Differences between the two groups were not significant for either of the two measures employed. There was also no significant difference between the self-concept of either the experimental, control, or “grand” group for either of the two measures employed. The “grand” group consisted of the total number of students in Grades 6-8 whose classes contained the subjects of the controls, exclusive of the control subjects (N=

225).

Social adjustment was measured by the Columbia Classroom Social Distance Scale. Difference between the two groups were highly significant for both measures and demonstrated the more positive social adjustment of the experimental group. A comparison of the experimental and control group with the “grand” group further clarified the more positive social adjustment of the experimental group. The students of the experimental group accepted their peers and were accepted by their peers more than the students in the “grand” group. There was no significant difference found in acceptance of peers between the control group and other students in a regular class. However, scores evidenced that the control group students were less accepted by their regular class peers. Reading growth, as measured by average reading scores obtained on the Intermediate Partial or Advanced Partial Batteries of the Stanford Achievement Tests over the period of 1 academic year, was not significantly different between the experimental and control groups. No significant differences were observed between the groups at different grade levels. Significant correlations in pre- and posttests suggested little growth in reading ability for either the experimental group or the control group. Goldstein, Moss, and Jordan (1965) attempted to compare the rate of progress of MR children assigned to special classes and those remaining in the

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regular grades on measures of mental, social, and academic achievement. The study was designed to compensate for methodological inadequacies of previous investigations. Special classes were established in three Illinois counties which previously had no provisions for primary age EM&. A total of 129 children scoring within a W e t IQ range of 56-85 were randomly assigned to two groups, special classes, and regular fust grade. A series of intellectual, academic, and personal adjustment measures were administered annually. The special class teachers had all received bachelors’ degrees in the education of the mentally retarded. The Illinois Curriculum Guide formed the basis for the educational program during the 4 years the special classes were in operation. The authors maintained that, in spite of attrition to about three-fourths the original sample, an analysis of the characteristics of the children who left the program indicated that the results of the study were not significantly affected by t h i s attrition. Both the groups increased significantly on intelligence test scores. The gains in IQ occurred primarily during the first year of school experience. There was no significant difference in IQ gains between the groups. Among the children with IQ 80 or below, the experimental group tended to exceed the control group. Personal adjustment both inside and outside school was considered. Mothers of experimental group members tended to view their children in a less derogatory manner. On neighborhood sociometric studies it was found that (1) control children tended to interact to a slightly greater degree with other children and (2)neither group was overtly rejected. The experimental group exceeded the control group in (1)greater originality, flexibility, and fluency in productive thinking on verbal tasks, but not on nonverbal tasks; and (2)freedom of interaction as determined by risk taking in answering difficult questions. There were no differences in anxiety levels in reading situations as measured by skin conductance tests. Hoeltke (1966) investigated the effectiveness of special class placement of EMR children by evaluating the areas of attitudes toward the teacher, selfconcept as a learner, academic achievement, social maturity, and behavior development. Two standardized tests, the Wide Range Achievement Test (WRAT) and Vineland Social Maturity Scale, were used to measure academic achievement and social maturity. Additional scales were developed to measure behavior development. The total sample population was composed of 122 children. The mean IQ of the special class sample (N = 72) was 65.34 and the mean CA was 138.39 months. The mean IQ of the regular class sample (N=50) was 66.40 and the mean CA was 139.16 months. The special class students had been enrolled in a special class for 3 or more years. The regular class students had never been enrolled in a special class. The special class sample scored significantly higher on Self-concept as a Learner, Desirable Group Activity, Peer Group Relations, Cooperation, and Leadership. The last four variables were derived from the Behavior Rating Scale

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filled out by the teacher. A comparison of paired individuals resulted in the Special Class Group scoring significantly higher only on the Self-concept as a Learner scale. The regular class sample scored significantly higher on reading, spelling, and arithmetic achievement. Paired students from the regular class scored significantly higher on the same achievement tests. Additionally, sex of the enrollee was not a primary determinant of academic, social, or emotional outcomes in either the regular or special class. On the Vineland Social Maturity Scale the difference between the two samples was not significant. No correlation was found on the Attitude Toward the Teacher scale or the Self Concept as a Learner scale and scores on the other variables considered. Hoeltke’s concluding observation was that on the standardized tests, the regular class children tended to score higher than special class children. When teachers rated pupils, the special class children tended to be rated higher. A somewhat different approach to the problem of the effects of special class placements is described by Mayer (1966). This author investigated the effects of early and late placement in special classes on “emerging self-concept.” The basic hypothesis tested was that early placement of EMRs resulted in more positive self-concepts than later placement. The subjects were 100 junior high school students enrolled in EMR classes. The CA range was 12-17 years with an IQ range of 50-75 and absence of observable physical, sensory, or emotional disability. The group was divided into early (0-3 years), middle (4-6 years), and late special class placement (7-9 years). Two tests of self-concept were used, Upsitt’s “The Children’s Self Concept Scale,” and a test developed by Mayer, Piers, and Harris called “The Way I Feel About Myself.” The results obtained were not significant with respect to the age of special class placement and the two measures of self-concept used in this study. Group differences between boys’ and girls’ self-concept were also nonsignificant. Smith and Kennedy (1967) attempted to evaluate the effects of a “comprehensive” classroom approach to special education. A total of 96 subjects with an IQ range of 50-80 were divided into three treatment groups: (1) 45 minutes per day of instruction and attention in small special classes; (2) 45 minutes per day in small group activity; (3)attendance in regular classrooms all day without special instruction or attention. The children were pretested first in September, 1961, and posttested in April, 1963, using the CAT, WISC, Vineland, and Johnson’s (1950) sociometric scale. No significant differences were found on the four dependent variables. The authors felt that certain limitations in the study may have led to the absence of significance. These concerned the short period of time covered, the number of grade levels studied simultaneously, and the “uncertain ability of the measures to detect small changes in behavior.” The authors concluded that “not only did retarded children fail to show a significant gain in performance as a result of participation in special classes, but retarded children who missed approximately 12.5% of their regular classroom activities failed to show a decrement in performance.”

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Carroll (1967) studied two school programs, “segregated” and “partially integrated” and the effect that each program had on self-concept and academic achievement during a l-year period. The study consisted of 39 students selected from five suburban districts in the Denver area. A total of 19 students were included in the partly integrated classes (half-day placement in regular elementary classes and half-day in self-contained EMR classes) and 20 students were involved full time in self-contained classes, All children fell within an IQ range of 60-80 on the Binet or WISC. Both groups were tested with the WRAT and an advanced form of the IISD 1 month into the study and following the completion of the school year. The results indicate a significantly greater reduction of self-derogations in the partially integrated group than in the segregated group (a mean change of 1.42 self-derogations for the integrated children versus 1.10 for the segregated). A significant change favoring the partially integrated group was recorded in the pre- and posttesting of the reading section of the WRAT. However, the spelling and arithmetic changes were not significant (actually the segregated group was slightly more proficient in the arithmetic test). The author concluded that partial integration results in a “better self-concept,” as indicated by a lower self-derogation score. More caution is suggested with respect to the achievement results, with Carroll indicating a need for further study of the academic results. In 1967, Meyerowitz tested the hypothesis that the “Educable Mentally Handicapped child (EMH) in the special classroom is more acceptable to his peers (whether classmates or not) than the EMH child in the regular classroom.” The base population consisted of 60 students, 30 of whom were randomly assigned to a self-contained class for the retarded (experimental group); the remaining 30 children stayed in regular classes (control group). In addition to the two groups of retarded children, there was a criterion group of 30 nonretarded children who were in the same classes as the controls. The latter group was matched on socioeconomic status with the two retarded groups. Of the total group of 90 children, 33 were found to meet requirements of sufficient peer interaction to be included in the study (10 experimental, 12 control, and 11 criterion). A sociometric interview was conducted with each child and measures of interaction were derived from the results of this interview. The findings tended to indicate that both experimental and control groups were more isolated from their classroom peers residing in the same neighborhood than were the intellectually normal criterion group members. Additional specific results viewed as negative by the author included the findings that (1) placement in a special class discourages the child in initiating contacts with peers and (2)regular class placement makes the child more reactive to his normal peers; however the latter group does not reciprocate. Towne, Joiner, and Schurr (1967) studied the effects of special class placement on self-concept. A total of 62 EMRs, CA range 6-15 years, who were on waiting lists for placement in segregated classes were selected for the study. An

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8-item test was administered prior to knowledge of placement and readminis tered four times during the first year of special class participation. The test items asked children how well they thought they were doing in school. The children showed significant improvement in self-concept of ability following placement. Scores increased until the end of the first year, when they began to decrease. The same authors reported some additional findings concerning a small subgroup of seven children who had returned to regular classes and were no longer labeled as EMR (Schurr, Towne, & Joiner, 1972). The self-concept score was found to be significantly lower 1 year following the reintegration into a regular class, In the report of Monroe and Howe (1971) two questions that relate to the social acceptance of EMR adolescents in an integrated junior high school were investigated: (1) Does the social acceptance of the retarded adolescent increase the longer he is in an integrated program? (2) Is the retarded adolescent’s social acceptance positively related to his social class? Five junior high schools in eastern Iowa were selected where retarded students were in classes with nonretarded students. However, in each school the number of hours the retarded were integrated and the types of classes involved varied. A total of 70 boys with CAs from 13-16 years (median = 14) and (Qs from 54-92 (median = 73) were selected. Nineteen physical education classes were selected (based on Rucker’s findings that acceptance was the same for academic and nonacademic classes). The length of time the EMR students had participated in these classes vaned from 1 to 3 years. No significant differences were found on the Ohio Social Acceptance Scale (SAS) among the mean scores for students in their first (N= 33), second (N = 28), or third year (N= 9) in an integrated program, although all scores were low relative to nonretarded students. Four groups were formed on the basis of Socioeconomic Index for Occupations. Two of the four groups consisted of EMR students divided into high (N= 30) and low (N = 40) social class. The other two groups were nonretarded, with IQ scores below 90, and likewise were divided into high (N = 30) and low (N= 40) social class. A significant difference was found between the mean SAS scores for special and nonspecial students. A significant difference was also found between the mean SAS scores for the high and low socioeconomic groups. The nonspecial high socioeconomic group had the highest SAS mean, while the special class low socioeconomic group had the lowest SAS mean. Lewis (1973) conducted a comparative investigation of four school environments for young EMR students (CA 6 to 10-9 years) on self-concept, academic achievement, attitude toward school, and social adaptive behavior. The students were drawn from lists of students in four school settings from 26 school districts. Group I children had been declared eligible for special education but had not been placed. These students (N= 16) were attending regular classes and

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“had not for all intensive purposes been labeled retarded.” Group I1 nonintegrated students (N = 20) had been placed in a self-contained class. Group I11 integrated students (N = 20), had been placed in special classes with a high degree of integration. Group lV resource room students (iV = 10) had been assigned to resource rooms or learning centers while maintaining membership in a regular class. All students had met the same eligibility requirements. School attendance ranged from always having been in special classes to never having been assigned to a special class. No significant differences were found among the four groups on self-concept as measured on The Way I Feel About Myself concept scale. However, females in Group I (Waiting List) and Group lV (Resource Room) scored significantly lower than the males in the groups. The analysis of the criterion variables, Sounds, Reading, and Numbers as measured by the Metropolitan Test, revealed no significant differences among the groups. Further analysis indicated that females in Groups I, II, and I11 scored significantly higher than males in reading. Group IV reported mean scores of males and females as almost equal. No significant differences among the groups regarding attitude toward school were found, An Adaptive Behavior Scale was completed by the teacher most familiar with each student, Analysis revealed significant differences for physical development and indicated that Group I1 (nonintegrated) were significantly lower than the other three groups on Adaptive Behavior. Teachers of students in Group I1 also perceived their students as having significantly less self-direction than did teachers of students in Group IV. Teachers reported students in Group I1 as significantly lower on socialization than the other groups. The study by Bradfield, Brown, Kaplan, Rickert, and Stannard (1973) was an attempt to demonstrate that, with modifications in regular classes, the special child can gain as much or more than these children gain in traditional selfcontained classes. Three children each of EMR and Educationally Handicapped (EH) classification were placed in modified third-, fourth-, and fifth-grade classes. Control children remained in self-contained special classes. The modified regular classes emphasized individualized instruction through the use of learning centers. After the first year, emphasis was placed on precision teaching with the development of a special cirriculum. The children were pre- and posttested for academic achievement, self-concept, and changes in behavior ratings. On academic development in third-grade children, the authors found no significant differences between the two EMR groups in reading, spelling, or arithmetic, using the CAT. A gain of .5 year was reported in the regular third class over the special class in arithmetic for EH children. No difference between groups was found in reading and spelling. In the fourth grade, the regular class group gained significantly more than special class children in reading and arithmetic as measured on the WRAT.There was no si&icant difference in any achievement area for EH children.

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Behavior ratings were reported using the Quay-Peterson Behavior Problem Checklist. EMR children in the third-grade regular class showed a significantly greater decline in disruptive behavior than was found among the special class students. The EH children showed improvement in social behavior to be equal in both regular and special classes. Both EMR and EH children in fourth-grade regular classes showed considerable improvement in interpersonal behavior compared to special class children. Walker (1974) also studied the effects of resource versus self-contained classes for the retarded. The hypothesis tested was that at the end of a 2-year period, EMR children taught in a regular class with resource room exposure (experimental group) would be less self-derogatory, better socially adjusted, and make greater academic gains than a control group assigned to self-contained classes. There were 29 experimental and 41 control children who were matched on CA, individual IQ test, and reading level. The children were pretested on the Bristol Social Adjustment Guides (an adaptation of the IISD),and the word reading, vocabulary, and arithmetic subtests of the Stanford Achievement Test. The results are somewhat difficult to interpret in the form in which they were presented in the article. Walker indicated that there were no differences found between the groups on the self-concept variable. Yet she then discussed “residual gains’’ (not defined) of the two groups and reported that there was no significant difference between the residual gains made over the 2-year period in the areas of self-concept, social adjustment, and arithmetic. Experimental children made “significantly better” residual gains in word reading and vocabulary than selfcontained children. The conclusion stated by the author was as follows: “The findings indicate that the academic and social-emotional needs of the mentally retarded child can be met as well, if not better, in the resource room program as in the special class.” Bruininks, Rynders, and Gross (1974) assessed the social acceptance of retarded children enrolled in regular classes who were receiving supportive assistance in resource learning centers within either suburban or innercity schools. Subjects were 65 elementary-school age mildly retarded, and 1234 nonretarded pupils enrolled in regular classrooms in adjoining urban and suburban school districts. The children in urban and suburban districts averaged between 10 and 11 years of age and had mean IQs of 75 and 69, respectively. Nonretarded pupils were selected from regular classrooms in the same schools attended by the retarded pupils. All retarded pupils received approximately 2 hours per day of “supplemental instruction” which varied to meet their individual needs. This instruction was given in a resource learning center by a certified special education teacher. The Peer Acceptance Scale used was a modified version of the Ohio Social Acceptance Scale. A peer acceptance score for each group member was obtained by totaling the rating received from each respondent and computing a mean. A

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sample of eight peers represented 2 5 4 0 % of a total class and was considered an adequate sample size. Correlations of .70 or above were obtained between this sample size and total class in an earlier study to validate this procedure. The principal findings were that mildly retarded children attending urban schools were significantly higher than nonretarded children in social acceptance among same-sex peers, while retarded children in suburban school settings were found to achieve significantly lower ratings than nonretarded children of the same sex. When peer ratings were combined (boys and girls, N = 4 of each), however, there were no differences between social acceptance of retarded and nonretarded in either school setting. 6. Studies of the Trainable Mentally Retarded

There have been few major studies of the efficacy of TMR education conducted to date. Unlike the EMR studies where integrated and segregated classes are compared, the TMR studies compare formal education versus no educational programming and/or public school versus institutional classes. “The New York Study” (Johnson & Capobianco, 1957) involved a 2-year investigation of the effectives of classes in public schools and institutions. Seven public school classes (N = 47) and two institutions (N = 96) were selected. With the Vineland Scale of Social Maturity no significant change in social quotient (SQ) was measured after the training period. The children with IQs less than 30 tended to decrease in SQ; children with IQs greater than 30 tended to increase slightly. To measure certain behavioral and academic changes, a behavior checklist was devised which included dressing, hygiene, table manners, following instructions, personal information, responsibility, and tool academics. Children with low IQs showed no gains; children with middle range IQs had gains that were lost in the second year; children with high IQs showed final slight gains. The Fels Behavior Rating Scale indicated some positive changes: (1) The public school children increased in tenacity and friendliness, and there was a reduction in competition; (2) the institutionalized children showed an increase in conformity and a decrease in gregariousness. The Illinois Test of Psycholinguistic Abilities (ITPA) was used as a language measure. A matched control group was established which was tested and retested at the same intervals. No significant difference in retest scores was found, nor were there significant differences on a test of articulation. Hottel’s (1958) 1-year “Tennessee Study” sought to determine if special classes produced greater development than training from parents in the home. There were 21 children matched on sex, clinical type, CA (8.6 years), and IQ (40.5) in two groups. One group was in public day classes; the second group was living at home without a special education program. Hottel used the StanfordBinet, Vineland Scale of Social Maturity, Fels’ Parent Behavior Rating Scale, and

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a Child Behavior Rating Scale he devised. The findings indicated no significant difference in score changes of either group in MA, IQ, Social Age (SA), SQ, behavior rating, or on the Fels. When the children were divided into low (30-40) and high (40-50) IQ groups, the high IQ special class children gained significantly in IQ, but not in SA or SQ. The 2-year “Texas Study” of Peck (1960) compared four groups of children: public school, private agency, and institutional classes, and children living at home receiving no training. Of a total of 30 children, there were 9 in the public school class, 6 in the private agency class, and 8 in the institution class. The remaining 7 children lived at home with no special education program. The CA range was 6-12 years; IQ range was 25-50. The study employed a single curriculum for all classes. Teachers were observed and supervised in the areas of provision for individual differences, social organization and classroom psychological climate, efficiency and orderliness of classroom activities, and ordermaintaining techniques. Peck used the Stanford-Binet, the Vineland Scale of Social Maturity, and a teacher rating scale which included the areas of social adjustment, self-care, language development, physical development, arts and crafts, economic usefulness, and music. The three classroom groups were rated six times per year. The nonschool group was rated three times per year. The findings showed more progress in learning as measured by the rating scale for the three classroom groups. No significant change in IQ or SQ was found in any of the four group. Cain and Levine (1963) in a 2-year study sought to assess the effects of special classes in institutional and community settings on the development of social competency. There were 182 subjects (IQ = 37.1, CA = 9.4 years, MA = 3.2 years) in four groups: (1) Community Experimental Group in which the children attended one of 31 public school classes and lived at home; (2) Community Control Group in which children received no schooling and lived at home; (3)Institutional Experimental Group in which children attended classes at the institution and lived there; (4) Institution Control Group in which children received no schooling and lived in the institution. Measurement was taken at the beginning and end of the 2-year period on an instrument devised by the investigators-The Cain-Levine Social Competence Scale. The scale consists of 72 items divided into four subtests: self-help, social skills, communication and initiative, and responsibility. Cain and Levine found that both the school and nonschool community groups made significant improvement in social competency. However, the difference between the two groups was not significant. Both school and nonschool institution groups significantly decreased in social competency. No significant differences were found between institutional experimental and institutional control groups. Both community groups made significantly greater gains than either institutional group.

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111. AN ANALYSIS OF THE EXPERIMENTAL CONTROL OF VARIABLES IN EFFICACY RESEARCH

A. Randomness

Random selection of children is a cardinal feature of valid experimental comparisons. As Kerlinger (1973) indicates, it is a prime consideration for the investigator to establish that experimental and control groups are approximately equated on variables which possibly may be related to the dependent variables. An inspection of the efficacy studies strongly suggests that, in most cases, randomness is not achieved. In surveying the efficacy studies, several types of subject selection procedures are observed. The procedures included either the use of preexisting groups or, in the minority of studies, random assignment to newly established groups. Each of these methods of selecting subjects will be examined in terms of how such selection might confound the interpretation of the research findings. The first approach to the use of existing groups is to select a school system that already has an established special education program and to study the relative efficacy of self-contained and integrated programs within that particular school system. Representative of this approach are the studies of Bacher (1964), Baldwin (1958), Kern and Pfaeffle (1962), and Walker (1974). The major problem in using existing groups from within the same school system is that even though the children in the varying treatment groups may be matched on a number of variables such as CA, MA, and IQ, there is still the distinct possibility that systematic bias enters into determining placement into preexisting programs. Such.a view has been suggested by Cegelka and Tyler (1970), Spicker and Bartel(1968), and Stanton and Cassidy (1964), among others. The main objection to using already existing groups is that such groups are not placed into alternate forms of educational treatments on a random basis. Rather, many school systems will transfer the most “educationally problematic” children into the segregated classes while retaining other less problematic children in regular classes. The term “educationally problematic” has no precise operational defmition, but is meant to cover a wide variety of school adjustment problems, motivational difficulties, and academic achievement failures on the part of the child. It also may include teacher and administrative unhappiness with the presence of such children within a regular class setting. Given limits to the number of children who may be placed in segregated classes, those most disturbing to the regular class teacher may be disproportionately represented in segregated EMR classes. It is a reasonable hypothesis that the school and adjustment histories of children in segregated classes may not be similar to those who are allowed to remain in integrated education. Thus it may be that any

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differences between groups may be due to antecedent conditions and not due to treatment effects. The notion that integrated and segregated EMR groups differ on some potentially important variables is suggested by the findings of Blatt (1958). As has already been reported, Blatt found that there were physical differences between self-contained and integrated EMRs, with the former group being significantly more underweight and having significantly more uncorrected or permanent physical defects than the latter group. The second approach to the use of existing groups is to select two or more school systems which differ in terms of whether or not they provide special educational services. The selection of segregated children would come from the system offering special educational services, and the integrated children would come from the system not providing any special education. Johnson (1961) is representative of the latter approach. This investigator selected experimental children who were enrolled in self-contained EMR classes. Johnson “assumed” that all retarded children in the experimental school systems were enrolled in segregated classes because of their availability, and that he had used adequate survey methods. The control group was selected from school systems with no defined programs for the MR. Control children were then identified by a series of screening procedures beginning with teacher identification of children they considered to be significantly below their peers intellectually. This group was subsequently administered a series of tests, including the Binet, which resulted in a control group of children whose IQs were found to be within the 50-75 IQ range. Johnson maintained that his subject selection procedures avoided earlier criticisms of sample bias which included an absence of assurance that (1) all EMRs in large schools had been identified and (2) that there were selective factors regarding which EMRs were placed in special education and which were retained in regular classes. Yet there remains the basic criticism that school systems may vary not only in terms of whether or not they provide special educational services, but also in matters concerning overall equivalence. For example, the period from 1955 to the present has been characterized by a rapid development of special education services in the schools. School systems that have not provided such special services have been generally smaller, poorer, educationally more conservative, and have provided a much narrower range of educational services than those systems which have developed special pupil programs. It is difficult for the authors to accept the case for equivalence of the school systems used to select experimental and control groups on a prima facie basis. While most efficacy studies compared existing groups, there have been a few that have used random placement to the various experimental conditions. The

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study of Goldstein et al. (1965) represents the most sophisticated approach to the problem of establishing experimentally equated groups and then randomly assigning them to experimental and control conditions. Goldstein et aL screened all 1807 first graders in three Illinois counties using the Primary Mental Abilities 5-7 Test. A total of 280 children scored 85 or less on this test, and were subsequently administered the Stanford-Binet, Form L. Identified were 120 children having Binet IQs of 60-85. Half of the children were assigned to four segregated special classes and half remained in regular first-grade classes. The Goldstein et al. method of randomization provided the opportunity for all entering first graders to be considered for placement in all experimental conditions. Antecedent educational experience was controlled by using only first graders and there was an equal opportunity for every child to be placed into experimental or control groups. As will be observed, there are many variables to be controlled, but Goldstein et aL have minimized one source of variance that is relatively uncontrolled in a majority of the efficacy studies in special education. Another frequently encountered but significant deviation from appropriate sampling procedure involves using unrepresentative sex distributions of EMR subjects. While many studies merely fail to report sex distributions, most studies used a 50-50 male-female ratio. However, virtually all prevalence studies of school-aged EMRs report a substantially higher proportion of boys than girls. Mumpower (1970), for example, found that in a school population surveyed over a 10-year period, 65.3% of the EMR children (N= 730) were boys and only 34.7% were girls. Yet many of the efficacy studies have simply ignored the sex variable in their sampling procedures. There are several studies that take cognizance of the sex distribution of the retarded, as evidenced by their selection procedures. Blatt (1958), studying a variety of characteristics of EMR children, included 29.3% girls in his study. Likewise, Stanton and Cassidy (1964) reported using a ratio of 1.86 males to 1 female in their study of EMRs. Employing a 50-50 male-female ratio appears warranted in TMR studies. In the same report described above, Mumpower (1970) found that of 195 Th4R children, 49.2% were boys and 50.8% were girls.

B. Control of Classroom and Instructional Variables The basic question being asked in efficacy is whether a program is doing what it purports to be doing. This goal is presumably incorporated into the curriculum that is being used. The achievement of the specifics is the responsibility of the teacher; the measurement of these specifics should be accomplished by using instruments sensitive to precise aspects of these goals or instructional objectives. Therefore,

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curriculum, teacher competency, and appropriate measurement constitute three essential classroom variables which should be considered in the conduct of efficacy research. The basic tenet in the creation of special classes is that the children to be served are of such a qualitative difference that the content and/or rate of presentation of the curriculum within the regular classes are inappropriate for them. To compensate, a specialized curriculim is established. Therefore, with the model of efficacy studies to date we are forced into a proposition of comparing special children on the basis of two sets of curricular content and objectives. As it is conceded that we are dealing with two diffdrent sets of materials and rates of presentation, it should be seen that we have not been measuring equal entities in terms of significant progress markers, yet we draw conclusions about program effectiveness as if we are. Most studies make no note of curriculum content. If the curriculum is not specified in the study, one does not know against which set of criteria achievement is being measured, nor is it possible to make an informed appraisal of achievement. In addition, since the curriculum is conceded to be different, the plausible points of comparability between the curriculum of the regular and special classes should be aligned in order that they may be meaningfully compared. If differences in rate of presentation and acquisition are conceded, growth should be seen from that point of view. That is, instead of comparing the scores on various instruments, one should be comparing gain scores. If curriculum content is different or presented at a reduced rate, then it is not appropriate to expect equal achievement on material. The criterion should be a percentage of achievement gain that is examined. The one study that attempted to deal with the curriculum dilemma was Bradfield et al. (1973). Within both the regular and special classes an attempt at curriculum control was made through “the precise defintion and structuring of curriculum” for use within both the regular and special classes. Specific details are not provided. Another alternative employed has been to control the curriculum of only the special classes, thereby establishing essentially the same testable content in each of these classes. In the studies by Peck (1960) and Goldstein et aL (1965) this type of control was maintained through use of the Illinois Curriculum Guides. Peck used the Illinois Curriculum Guide for Teachers of Trainable Mentally Handicapped Children. This guide includes the content areas of social adjustment, self-care, language development, physical development, music, arts and crafts, and economic usefulness. Even greater control of the curriculum was afforded by using a 4month preplanning period. Prior to the beginning of the teaching, the investigators and teachers met on two afternoons per week for 4 months, experimenting with tasks and activities and also coordinating plans and methods. Such meetings continued after teaching began. The lesson plans developed included: (1) activities within each curriculum area, (2)the methods of

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teaching each activity “SO that each teacher could use essentially the same method of teaching,” (3) the mutually agreed upon materials for each activity. Lesson plans were projected for the month and then further developed for each week. If deviations were made, the rationale and substitution had to be recorded. However, substitutions of activities were required to deal with the same content as the activity for which the substitution was made. Goldstein et aL (1 965) used the Illinois Curriculum Guide for Teachers of the Educable Mentally Handicapped. This guide includes the areas of arithmetic, frne arts, language arts, physical education, practical arts, science, and social relationships. Similar control of the curriculum of the regular classes is not mentioned. With the establishment of a program’s content, the next question to be raised is the effectiveness with which it is being implemented. If we are to compare accurately development and achievement of subjects, we must be certain that all the teachers of the program have approximately equal ability to match content, child, and appropriate methodology and materials; all teachers need to demonstrate a minimum standard of methodological skill; and all teachers must be performing an equally effective job. As part of their observations Cain and Levine (1963) made an analysis of the percent of quality instruction taking place in their research classrooms. In the community schools they judged 44% of the class day to be instructional in nature; 29% of this was of “high adequacy.” In the institutional schools they judged 35% of the class day to be instructional in nature; 1.7% of t h i s was of “high adequacy.” The criteria for this analysis were quantity and accessibility of material for instruction, teacher supervision of activities, number of children engaged in a learning activity, individualization of instruction, opportunity provided for the children to assume responsibilities, teacher evaluation during class, and the amount of teacher attention concerned with deviant behavior. When looking at the dates of the preponderance of efficacy studies, one notes that the number of adequately trained and certified special education teachers was limited during that period. Wide differences existed in the amount and nature of course and practicum experiences required at various training institutions. For many years, obtaining “intensive summer preparation” or “add-on certification” was a very frequent practice in special education. It is doubtful that such hasty preparation provides for adequate and/or effective training of a competent teacher. Further, it brings into question the problem of the comparative competence of both special education and regular education teachers within well-controlled studies. Three attempts have been made at reducing teacher related variance: Peck (1960) with TMR teachers, Goldstein et al. (1965) with special education teachers, and Bradfield et al. (1973) with the special and regular education teachers. Peck and his associates observed the procedures of each teacher to assure the

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implementation of the methods and materials decisions made during their planning sessions, and to assure equalization of teaching and curriculum between the groups. They also studied and discussed with each teacher the progress and behavior of her students. Attempts at control of the effectiveness and equality of the teaching was done through the use of Sanders’ Descriptive Schedules. Each teaching situation was described by three different observers using the following schedules: provision for individual differences; social organization and classroom psychological climate; efficiency and orderliness of classroom activities; order maintaining techniques. In that each class will vary as a function of the teacher, it would be desirable to rotate the teachers among the classes to assure equalization of the teacher competency variable. However, this is a practical problem, especially in studies with an in situ sample. Coldstein et al. (1965) made such an attempt by having no individual teacher teach the same class for more than 2 years. As further controls, each of their special education teachers had MR certification, teacher conferences were held, and close supervision maintained. During the academic year the teachers met at approximately 6-week intervals to discuss classroom experiences and plans. During the summer, evaluation of the past year and preparation for materials for the next were accomplished. Bradfield et al. (1973) attempted to control the teacher variable in both special and regular classes through the use of a single instructional philosophy, namely, “individualization of instruction.” During the first year the learning center approach coupled with the use of behavior modification techniques was used. The orientation was changed during the second year to precision teaching; specifically, “the precise definition and structuring of curriculum and consequences for appropriate performance.” Teachers underwent an inservice training program in techniques of individualization of instruction. New teachers had additional workshops and spent 1 week in a model classroom. One variable which has not been sufficiently considered in efficacy research is that of differing expectancy levels for academic achievement and social behaviors of EMR students that are held by regular and special class teachers. Although conflicting evidence exists as to the specific effects of teacher expectancy upon student behavior, the possible effects of this variable should be considered in an investigation. Teacher expectancy should be of particular concern when an investigator is using teacher completed checklists of social or adjustment behaviors such as in the studies by Blatt (1958), Elenbogen (1957), and Mullen and Itkin (1961). When such checklists lack an objective standard, the findings may be used on what Gardner (1966) refers to as “differences in frame of reference.” Identical behaviors exhibited by EMR students in the special and regular class may be judged qualitatively different, based on the teachers expectancy of her students. Bradfield et al. (1973) attempted to get at this source of discrepancy by use of “precision charts” to measure within-class

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progress. Precise criteria for the presence or absence of behavior are reported to have been established for progress. The charts included an arithmetic problemscorrect rate chart, arithmetic problems-incorrect rate chart, reading correct and incorrect rate charts, and a social behavior rate chart. This procedure involving the use of precisely defined behavioral criteria has the effect of neutralizing the influence of teacher expectancy. C. Appropriateness of Measuring Devices

Measurements of achievement and social behaviors are as much a result of the instrument used as they are of the instruction that takes place within the classroom. There have been essentially four achievement instruments used within the research that has been reviewed. These include the Stanford Achievement Test (Bacher, 1964; Stanton & Cassidy, 1964; Thurstone, 1959; Walker, 1974), the CAT (Blatt, 1958; Bradfield et aL, 1973; Smith 8c Kennedy, 1967), the WRAT (Carroll, 1967; Hoeltke, 1966), and the Metropolitan Achievement Test (Lewis, 1973). A first question of importance concerning these instruments is that of the validity. For instance, the authors of the Stanford Achievement Test (Kelley, Madden, Gardner, & Rudman, 1968) completely neglect empirical validity data. They present the statement that they “sought to insure content validity by examining appropriate courses of study and textbooks as a basis for determining the skills, knowledge, understandings, etc., to be measured.” Not only is content validity not sufficiently present, but concurrent validity with comparable achievement batteries was neglected. Similarly, this lack of content validity is found for the other tests as well. In his review of the WRAT, Thorndike (1972) states that “the content validity of the test is not considered by the authors at any point. This review does not believe that it would be judged to be high.” The absence of such information leads to extreme difficulty in interpretation of the results of efficacy studies, for it first raises the question as to whether the tests are in fact measuring appropriate achievement for the regular classrooms. Furthermore, if there is question of their use with regular students, how can they be a valid measure for achievement in the special class where it must be conceded that the curriculum is, to say the least, modified? Another question is that of sensitivity of the instruments. Consider the apparent discrepancies between the findings of Smith and Kennedy (1967) who, in their study, used the rather specific results of the CAT, and Carroll (1967) and Hoeltke (1966) who used in their study the less sensitive and more limited findings which can be obtained from the WRAT. Smith and Kennedy reported the results of the CAT, with its numerous set of academic skills and subskills and found no significant difference between groups; these authors suggested that one problem of interpreting the findings was “the uncertain abilities of the measures

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[CAT] to detect small changes in behavior.” However, by using an even less sensitive instrument in their studies, i.e., the WRAT,Hoeltke and Carroll both found significant improvement. The question remains as to how such discrepant results can be reconciled. Another general but related problem is that variations in the sensitivity of measuring instruments used in the various efficacy studies highlights the difficulty in generalizing from research employing widely diverse tests. The validity and reliability of the measures of social behavior used in various efficacy reports must also be questioned. Blatt (1958) stated in his study that validity testing had not been performed on the New York City Scales of Social Maturity and Emotional Stability, which was used in his study on EMR characteristics. Similarly, questions of validity are raised by Hoepfner, Stem, and Nummedal(l971) on other frequently used measures of social behavior. These authors, after scrutinizing the available statistical research, rated the validity of the Bristol Social Adjustment Scale (a later adaptation of the IISD) and the CTP as “fair,” and their reliability as “poor.” The use of the CTP as a dependent measure has been reported in a number of efficacy studies (Blatt, 1958;Cassidy & Stanton, 1959;Johnson, 1961;Kern & Pfaeffle, 1962). Kern and Pfaeffle and Cassidy and Stanton found significant differences between groups; Blatt and Johnson found no such differences using major category scales. In his discussion of the use of the CTP, Gardner (1966) raises serious questions regarding the use of subtest scores instead of major category scores. Further, as to the CTPs appropriate use, Gardner (1966)states that since the retarded subjects got mean raw scores below the fifth percentile, “One could assume that, to the extent the CTP actually reflects significant and meaningful aspects of personal and social adjustment, the mentally retarded are inferior to the group represented by the test norms.” A possible interpretation of this fact is “that the test is not an appropriate instrument for use with the mentally retarded.” Where curricular areas were not included on available standardized instruments, many investigators chose to devise checklists as measurement instruments. However, validity and reliability must be brought into question. Without the establishment of criterion references to compensate, such checklists are open to the subjectivity of the rater. Also, there needs to be the established outside norms against which a sample population may be compared. In this way, one can then measure whether regular or special education programs most effectively and efficiently instruct the child. Measuring against standardized norms is a questionable procedure. If we accept that the norms of most standardized measures are inappropriate for the special education child, does this necessitate the establishment of deviation norms against which to measure to the achievement of this population? The seeming popularity of the use of sociometric techniques (Baldwin, 1958; Bruininks et aZ., 1974; Johnson, 1961; Monroe & Howe, 1971) as a valid

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measure of social development has been questioned by Quay (1963). She points out two weaknesses inherent in their use with special education subjects. First she states, “it is reasonable to expect them [special class students] to name the children who are present at the time they take the test. Second, on the basis of their experiences, special class teachers are likely to have lower internal norms for personal traits in children than are regular class teachers” [p. 6721.

IV. THE FUTURE OF EFFICACY RESEARCH IN SPECIAL EDUCATION

On the basis of the review of efficacy research and the analysis of experimental variables to be considered in such research as just presented, it should be clear that generating clear-cut studies in this area is an exceedingly difficult task. At a minimum, we need to sensitize researchers in this field to attempt to reduce error factors associated with lack of random sampling, poor matching of subjects, inappropriate or invalid test instruments, unclear curricula, as well as poorly stated objectives of the intervention procedures. It was indicated earlier that since most of the efficacy studies were performed in the 1950s and early 19609, a major source of uncontrolled variance was related to the high probability that a significant number of special education teachers had received minimal formal and specialized training in dealing with retarded children. In the late 1960s and early 1970s we have witnessed the emergence of a significantly greater number of organized training programs, and it is proposed that teachers trained in the last decade may have a firmer basis for providing more effective educational services. Of course, such a proposition needs to be evaluated empirically. In the same vein, the past decade has produced the emergence and refinement of a larger number of teaching strategies characterized by greater specificity of educational objectives, e.g., precision teaching, applied behavioral analysis, task analysis, and similar approaches. There is mounting evidence that such approaches have produced specific and circumscribed gains in educational and social performance. However, there are no comprehensive studies involving the efficacy of these “behavioristic” approaches which span relatively prolonged educational periods and involve a variety of academic subjects and/or social variables. How Can Future Efficacy Studies be Improved?

The concluding section of this chapter deals with three general classes of variables, with specific recommendations on techniques for reducing uncontrolled sources of variance. The variables to be discussed include teacher selec-

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tion, standardization of curriculum, and use of measuring and evaluation instruments. The first variable, selection of teachers, has been almost consistently neglected. While individual teachers will always vary somewhat in their approach, the following suggestions are offered in terms of helping to reduce the degree of teacher variability: (1) All teachers participating in the study should meet certain basic criteria in terms of their education and prior experience. One method of approaching t h i s problem is to select only teachers who have been systematically evaluated during their formal training in a competency-based college or university special education program. While such an approach is far from foolproof, at least it can be certified that the teacher was exposed to a variety of training experiences and was able to demonstrate a series of teacherrelated skills deemed important by professional special educators. Thus, efficacy researchers who use a population of competency-based trained teachers can be reasonably sure that such teachers possess certain minimum requisite skills at the time they begin teaching. Related to the discussion of prior training is the recognition that university departments of special education impose a variety of methodological and theoretical viewpoints which have a significant bearing on the general approach a teacher adapts in subsequent teaching efforts. Rather than being frustrated by these training program variations, such variations can be incorporated into the design of future efficacy studies. For example, two competency-based training programs vary in their basic theoretical orientation: Department “A” is highly behavioristic, with much emphasis in defining specific behavioral objectives, and Department “B’ is psychoeducational in its approach. Each department has developed a series of exiting competencies which are used to evaluate students. It not becomes possible to evaluate the effectiveness of approach “A” versus approach “B,” although it is recognized that there are additional independent variables to be controlled in such an evaluation procedure. The second variable to be considered is the need to standardize the curriculum used in the study. Training workshops on the application of a teaching strategy to curriculum content are required to increase standardization. The workshops should be of sufficient duration to assure adequate mastery of both the methodological approach and curriculum content. Exiting criteria for teacher proficiency should be clearly indicated and mastered prior to the start of the research. Further, once the study is underway, the researcher should engage in a series of checks on classroom activities to determine whether or not the teacher is continuing to use the specified methods and curriculum, according to the criteria established during the training workshop. Time or event sampling of classroom activities represents one way of evaluating the problem of fidelity of stated educational intervention on the part of the teacher.

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The third variable related to use of appropriate measuring instruments in evaluating educational and behavioral results. Some of the studies reported earlier used instruments that were relatively well standardized. However, it is also necessary to make certain that the standardized test used is applicable to the population being studied in the efficacy research. Gardner (1966) presents one example of the misuse of a standardized test (CTP)and its use on populations of subjects not originally considered in the standardization. A final suggestion concerning measuring instruments involves the use of rating forms. While such instruments will continue to be used, the writers strongly recommend that the language of the rating forms be stated in specific behavioral terms, with subjective judgments being eliminated or kept to an absolute minimum. Further, it is assumed that intermittent reliability tests on all rating and observational instruments will be made throughout the course of the study and not restricted to the initial phase of the research. REFERENCES Bacher, J. The effect of special class placement on the self-concept, social adjustment, and reading growth of slow learners. Unpublished doctoral dissertation, New York University, 1964. Baldwin, W. K. The educable mentally retarded child in the regular grades. Exceptional

Children, 1958,25,106-108,112. Blatt, B. The physical, personality, and academic status of children who are mentally retarded attending special classes as compared with children who are mentally retarded attending regular classes. American Journal of Mental Deficiency, 1958,62,810-818. Bradfield, R. H.,Brown, J., Kaplan, P., Rickert, E., & Stannard, R. The special child in the regular classroom. Exceptional Children, 1913,39,384-390. Bruininks, R. H.,Rynders, J. E., & Gross, J. C. Social Acceptance of mildly retarded pupils in resource rooms and regular classes. American Journal of Mental Deficiency. 1914,78, 377-38 3. Cain, L. F., & Levine, S. Effects of community and institutional school programs on trainable mentally retarded children. CEC Research Monograph, 1963,No. B-1. Carroll, A. W. The effects of segregated and partially integrated school programs on self concept and academic achievement of educable mentally retardates. Exceprional Chil-

dren, 1967,34,9349. Cassidy, V., & Stanton, J. An investigation of factors involved in the educational placement of mentally retarded children. USOE Project No. 043, U.S. Office of Education, 1959. Cegelka, W. J., & Tyler, J. L. The efficacy of special class placement for the mentally retarded in proper perspective. Training School Bulletin, 1970,67,33-68. Cowen, P. A. Special class vs. grade groups for subnormal pupils. School and Society, 1938,

48,21-28. Elenbogen, M. L. A comparative study of some aspects of academic and social adjustment of two groups of mentally retarded children in special classes and in regular grades.

Dissertation Abstracts, 1951,17,2496. Gardner, W. I. Social and emotional adjustment of mildly retarded children and adolescents: Critical review. Exceptional Children, 1966,33,97-106. Goldstein, H.,Moss, J., & Jordan, L. The efficacy of special class training of the develop

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ment of mentally retarded children. USOE Project No. 619, U.S. Office of Education, 1965. Hoeltke, G. M. Effectiveness of special class placement for educable mentally retarded children. Unpublished doctoral dissertation, University of Nebraska, 1966. Hoepfner, R., Stern, C., & Nummedal, S . G. (Eds.) CSE-ECRCPreschool/Kindergarden Test Evalucrtions. Los Angeles: Center for the Study of Evaluation and Early Childhood Research Center, Graduate School of Education, University of California at Los Angeles, 1971. Hottel, J. An evoluotion o f Tennessee's day chss pmgrom for severely mentally retarded tminoble children. Nashville, Tenn.: State Department of Education, 1958. Johnson, G. 0. A study of the social position of mentally handicapped children in the regular grades. Americm Jountrrl of Mentol Deficiency, 1950,55,60-89. Johnson, G. 0. A comparative study of the personal and social adjustment of mentally handicapped children placed in special classes with mentally handicapped children who remain in regular classes. Unpublished manuscript, Contract M2514, U.S. Department of Health Education and Welfare, 1961. Johnson, G. O., & Capobmco, R. J. Research project on severely retarded children. New York: Interdepartmental Health Resources Board, 1957. Kelley, T., Madden, R.,Gardner, E., & Rudman. H. Stonford Achievement Test. New York: Harcourt, 1968. Kerlinger, F. N. Foundations ofbehoviorol research. New York: Holt, 1973. Kern, W. H., & Pfaeffle, H. A. A comparison of social adjustment of mentally retarded children in various educational settings. American Journal o f Mentol Deficiency, 1962, 67,407-413. Lapp, E. R. A study of the social adjustment of slow-learning children who were assigned part-time to regular classes. Americon Jouml of Mentol Deficiency, 1957,62,254-262. Lewis, M. A comparison of selfancept, academic achievement, attitude toward school and adaptive behavior of elementary school children identified as educable mentally retarded in four different school environments. Unpublished doctoral dissertation, University of Michigan, 1973. Mayer, C. L. The relationship of early special class placement and selfconcepts of mentally handicapped children. Exceptwnol Children, 1966,33,77-81. Meyerowitz, J. H. Selfderogations in young retardates and special class placement. Child Development, 1962,33,443-451. Meyerowitz, J. H. Peer groups and special classes.Mento1Returdation, 1967,5,23-26. Monroe,J. D., & Howe, C. E. The effects of integration and social class on the acceptance of retarded adolescents. Education ond lhiningof the Mentolly Retoded, 1971,6,20-23. Mullen, F. A., & Etkin, W. Achievement ond odjustment o f educable mentolly hmdicapped children fn xpeckrl cloxes m d in regulor closes. Chicago: Chicago Board of Education, 1961. Mumpower, D. L. Sex ratios found in various types of referred exceptional children. Exceptionol Children. 1970,36,621-622. Peck, J. R. A comparative investigation of the learning and social adjustment of trainable children in public school facilities, segregated community centers, and state residential centers. USOE Project No. 6430, U.S. Office of Education, 1960. Pertsch, C. F. A comparative study of the progress of subnormal pupils in the grades and in special classes. Unpublished doctoral dissertation, Teachers College, Columbia UNversity. 1936. Porter, R. B., & Milazzo, T. C. A comparison of mentally retarded adults who attended a

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Quay, L. C. Academic skills. In N. R. Ellis (Ed.), Handbook of mental deficiency. New York: McGraw-Hill, 1963. Schurr, K. T.. Towne, R. C., &Joiner, L. M. Trends in selfconcept of ability over two years of special class placement. Journal of Special Education, 1972,6,161-166. Smith, H. W., & Kennedy, W.A. Effects of three educational programs on mentally retarded children. Perceptual and Motor Skills, 1967,24,174. Spicker, H. H., & Bartel, N. R. The mentally retarded. In G. 0. Johnson & H. D. Blank (Eds.), Exceptional children research review. Washington, D.C.: Council for Exceptional Children, 1968. Stanton, J. E., & Cassidy, V. M. Effectiveness of special classes for educable mentally retarded. Mental Retardotion. 1964,2,8-13. Thorndike, R. L. Tests & reviews: Achievement batteries. In 0. K. Buros (Ed.), The seventh mental measurementsyearbook. Vol. 1. Highland Park, N. J.: Gryphon Press, 1972. Thurstone. T. G. An evaluation of educating mentally handicapped children in special classes and in regular grades. USOE Project No. 6452, U.S. Office of Education, 1959. Towne, R. C., Joiner, J. M., & Schurr, T.The effects of special classes on the self-concepts of academic ability of the educable mentally retarded. Paper presented at the 45th annual Council for Exceptional Children convention, St. Louis, April 1967. Walker, V. S. The efficacy of the resource room for educating retarded children. Excep tional Children. 1974,44 288-289. Warren, K. An investigation of the effectiveness of educational placement of mentally retarded children in a special class. Dissertation Abstmcts, 1962,23,2211.

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Subject Index

A

Digit span test, 211 Discriminative function, of self-injurious behavior, 13-16 Distractibility, 153-159

Abstractions, 49-5 3 Auditory serial recall test, 211 Avoidance learning, self-injurious behavior as, 11-1 3

E Environment, linguistic, 69-76 E v o l ~ t i o psychology, ~y 35-5 3 abstractions and logical problem solving and, 49-53 brain and, 39-42 digit span and, 48 learning and complex, 49 strategic behavior in, 4 8 4 9 performance congruence and, 47 reasoning and, 39 rote memory and, 4 7 4 8 stereotyped response and, 45-47 types of evolution, 3 6 3 7 uniquely human traits, 37-39 Expansion, language acquisition and, 76-78

B Brain, 39 negentropic, 40-42 self-organizing, 40 C

Caste and class, malnutrition and, 204-205 Coding, cross-modal, 212 Cognitive psychology, 105-1 34 changes in, 108-109 cognitive instruction and, 127-1 33 explanation by specification of unobservablesand, 109-113 individual difference tests and, 113-1 27 present status, 107-108 Color naming test, 212 Communication,see Language acquisition Comprehension,language acquisition and, 87-88 Computer programs, 110 Correction, language acquisition and, 79-80 Cross-modal coding, 212 Crying, language acquisition and, 63-64 Cultural deprivation, 141-144

F Facial expression, language acquisition and, 65-66 Figure Copying Test, 210 Flow charts, 110

C Gestures, language acquisition and, 66-67

D I

Design memory test, 211 Digit span, as rote learning or strategic behavior, 48

Imitation, language acquisition and, 78-79, 86-87 25 7

258

Subject index

Individual difference tests, 113-127 mvarian~tests, 119-120 US^ Of, 113-115,127 validation of cognitive theory by, 120-121 Instruction, cognitive, 127-133 Intelligence testing, 160-162 Interpretation, language acquisition and, 79 Interstimulus interval in electrodermal response conditioning, 178-179 in eyelid conditioning, 177-178

L Language acquisition, 57-98 child language learning strategies, 85-89 learning in, 59-60 linguistic environment and, 69-76 maternal speech and, 76-85 preverbal communication strategies in, 63-69 social agent in communication deficiencies and delayed language development and, 93-94 communication model and, 96-98 communicative match and, 91-93 implications for language intervention, 94-96 theoretical perspectives on, 60-62 Learning, 144-153 complex, 49 in language acquisition, 59-60 of mazes, 150 pairedassociate, 148-149 probability, 150 rote, digit span as, 48 strategic behavior in, 49 Logical positivism, 110-1 11

M Malnutrition, 195-220 class and caste and, 204-205 cognitive competence and, 206-207 hypotheses, 212-213 method, 207-21 2 results, 213-220 mental development and, 1 9 6 2 0 0 experimental design in, 200-204

Maze learning, 150 Memory, 144-153 for designs, 21 1 rote, 47-48 short-term, visual, 2 11 Memory trace, inaccessibiLity of, 146-148

N Nonvocal behavior, language acquisition and, 65-69 0

Operationism, 11Ck111 P Pairedassociate learning, 148-149 Perceptual 163 Performance congruence, 47 Personality testing, 160-162 Preverbal communication strategies, 63-69 Probability learning, 150 Problem solving, 49-5 3 Proteincalorie malnutrition (pCM), see Malnutrition Punishment, for self-injurious behavior, 22-26

R Raven’s Colored Progressive Matrices, 210 Reading test, 2 12 Reasoning, 39 Reinforcement, language acquisition and, 80-8 1 Response, stereotyped, 45-47 Retardation, as thinking disability, 42-43 Retention, long-term, 146 Rote learning, digit span as, 48 Rote memory, 47-48 S

Self-injuriousbehavior, 1-30 collateral behaviors and symptom substitution for, 26-29

259

SUBJECT INDEX

developmental interpretations, 10 differential reinforcement of alternative behavior, 17-19 homeostatic function of, 6-7 as learned behavior, 10-16 organic account, 9-10 physical punishment for, 22-26 prevalence of, 2-5 psychodynamic explanations, 7-9 removal of positive reinforcement for, 19-22 Semantic differential, 162-163 Semantics, language acquisition and, 74-75 Serial position effects, 150-152 Serial recall test, auditory, 211 Signal detection, 159-160 Smiling,language acquisition and, 65-66 Social agent, in language acquisition, see Language acquisition Special education, 225-253 control of variables in efficacy research appropriateness of measuring devices, 249-25 1 classroom and instructional variables, 245-249 randomness, 243-245 for educable mentally retarded, 2 2 6 2 4 1 future of efficacy research in, 251-253 for trainable mentally retarded, 241-242 Speech, maternal, language acquisition and, 7685 Stimulus trace, 173-191 decay in classical conditioning, 176-177 methodology confounding variables, 179-1 8 1

A 6 8 7 C B D 9 E O

F 1 6 H 1 J

2 3

4 5

interstimulus interval in electrodermal conditioning, 178-179 interstimulus interval in eyelid conditioning, 177-178 retardation and, 174-175 Stimulus tracedelay conditioning normal-retardate comparisons, 183-189 normal subject data, 181-183 Strategic behavior, digit span as, 48 Symptom substitution, for self-injurious behavior, 26-29 Syntax, language acquisition and, 70-73

T Thinking disability, retardation as, 42-43 Transfer, 148-149

V Validation, 111-1 13 convergent, 111-112 Visual short-term memory test, 211 Vocalization, language acquisition and, 64-65 Von Restroff phenomenon, 152-153

W Word order, language acquisition and, 74

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