Intellectual Characteristics of School Labeled Learning Disabled Children MONTE D. SMITH
J. MICHAEL COLEMAN PAUL R. DOKECKI EARL E. DAVIS Abstract: Over 200 school labeled learning disabled children enrolled in 23 classrooms for the learning disabled were administered the Wechsler Intelligence Scale for Children-Revised (WISC-R). Results indicated that 37% of the children tested did not meet the single most generally agreed upon requisite for learning disabled classification, which is that of a normal level of intellectual functioning. However, regardless of the relative level of intellectual functioning, mean Performance la's were significantly greater than .mean Verbal la's. Moreover, there was marked (and statistically reliable) heterogeneity among mean subtest scaled scores, although children with normal and subnormal intelligence exhibited similar patterns of WISC-R subtest scores.
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,RES ENT research demonstrates the need to specify clearly the intellectual characteristics of children identified and labeled by the schools as learning disabled. Such specification is an important step in the process of designing and implementing effective and efficient service delivery systems for this major population. Although Black [1974) demonstrated that the decade from 1962 to 1972 witnessed an explosion of publications on the topic of learning disabilities [and that most of these reports were descriptive in nature), there is still little agreement on the intellectual attributes of learning disabled children. Wepman, Cruickshank, Deutsch, Morency, and Strother (1975) suggested that: There is little agreement either in medicine or in education on criteria for identifying children
MONTE D. SMITH is Assistant Professor of Psychology and Director of the Research and Evaluation Component of the Psychoeducational Agency/School System (PASS) Model Project, PAUL R. DOKECKI is Professor of Psychology, Director of the Program for Human Development Specialists, and Co-Principal Investigator for the PASS Model Project, and EARL E. DAVIS is Associate Professor of Special Education, Director of the Child Study Center, and Co-Principal Investigator of the PASS Model Project, George Peabody College for Teachers, Nashville, Tennessee; and J. MICHAEL COLEMAN is currently a doctoral student in Special Education, University of Virginia, Charlottesville. He was formerly coordinator of the PASS Project. The research reported herein was funded under US Office of Education, Bureau of Education for the Handicapped, (USOE/BEH) Contract No. OEC-O-74-8726. The opinions expressed, however, do not necessarily reflect the position or policy of USOE, and no official endorsement should be inferred. March 1977
with ... learning disabilities. Because the disabilities presented by these children are extremely heterogeneous, the search for any commonality ... has so far been fruitless. [p, 302)
In a similar vein, Bryan (1974) emphasized the multitude of characteristics which have been attributed to children labeled learning disabled, and suggested that this "mishmash of characteristics" has received little empirical support. She cited the following as negative attributes that have been mentioned as a problem in the learning disabled: hyperactivity, perceptual motor impairments, emotional lability, general coordination deficits, disorders of attention (short attention span, distractibility, perseveration), and impulsivity, disorders of memory and thinking, specific learning disabilities (reading, writing, spelling, arithmetic). disorders of speech and hearing, equivocal neurological signs, and electroencephalographic irregularities. There is much research on supposed deficiencies in auditory and visual processing claimed to be associated with learning disabled children. Yet, Bryan (1974) presented evidence that these most popular of learning disability stereotypes have not received substantial empirical support. Moreover, Hammill and Larsen (1974). in their review ofpsycholinguistically oriented investigations, indicated that the validity of this information processing approach to learning disabilities remains unproven. One generally claimed characteristic of the learning disabled child is normal intelligence. Both Ames (1968) and Bryan (1974). however, reported that approximately 25% of two samples of children labeled learning disabled were subnormal in intellectual functioning, and hence could ha ve been characterized more appropriately as educably mentally retarded. Even on the criterion that is most uniformly cited as a requisite for learning disability classification [i.e., normal intelligence), there is disagreement as to the point along the continuum of measured intellectual capacity that should serve to distinguish normal from subnormal intelligence. An IQ of 80 or 85 is often used as the cutting point, but Mercer (1975) recently argued that the normality cutting point should be 70. Recently, investigators have examined the Wechsler Intelligence Scale for Children (WISCj and the Wechsler Intelligence Scale for Children-Revised (WISC-R) subtest scaled score profiles of learning disabled children to determine if consistent patterns of Exceptional Children
scores distinguish them from normal children [Bannatyne, 1968. 1971. 1974; RugeI, 1974). Both Bannatyne and Rugel have reported distinct subtest profiles for learning disabled children, with pronounced "peaks" and "valleys" which are reputed to represent subcomposites of intellectual ability possibly associated with some aspects of learning disabilities, This investigation examined the WISC-R profiles of a large sample of school labeled learning disabled children with the objective of providing a composite intellectual profile in terms of Verbal IQ, Performance IQ, Full Scale IQ, and subtest scaled scores. The following specific questions were addressed: 1. What proportion of school labeled learning
disabled children failed to meet the criterion of normal intelligence? 2. Were there significant Verbal IQ versus Performance IQ discrepancies, and if so, did both relatively high IQ and low IQ children exhibit similar discrepancies? 3. Were there pronounced "peaks" and "valleys" in subtest scaled scores, as suggested by Bannatyne (1968, 1971, 1974) and Rugel (1974). or were the subtest scaled scores uniform in magnitude? 4. If subtest scaled score heterogeneity [i.e., distinct "peaks" and "valleys") was evident, were the patterns similar for relatively high IQ and low IQ children?
Method Participants
Participants were 208 children enrolled in 23 learning disability classrooms in a large metropolitan school system in the fall of 1974. Children in these 23 classrooms constituted approximately 79% of all children assigned to learning disability classes in the school system. The remaining 21% of learning disabled children in the school system were enrolled in two schools which declined to participate in the study. Although it was impossible to verify, it was felt that the children in these two schools were comparable. The learning disability referral procedure was uniform across the school system and schools with learning disability classrooms were feeder schools, with children bussed to the special classrooms from schools without learning disability classes. The children were independently verified as learning disabled by the school system prior to data collection. The children were 353
severely deficient academically, as indicated by an average discrepancy between obtained Metropolitan Achievement Test grade equivalents and age-appropriate grade placements of approximately 2 years. Children were not visually or hearing impaired. Participants had been enrolled in learning disability classes an average of 12 academic months. The age range was from 6 years, 3 months, to 12 years. 1 month (Mean =9 years, 9 months). The children were 76% male and 81% Caucasian. Procedure
The WISC-R was administered individually to children by trained personnel of the George Peabody College Child Study Center. The sample was divided into high and low IQ subgroups by using a normality criterion that embodied both an overall (Full Scale) minimum IQ (76) and a requirement that the child obtain either a Verbal or Performance IQ of at least 90.
Results
The normality criterion was not met by 76 children (37%). Thus. 37% of the participants did not meet the criterion most commonly accepted as a requisite of learning disabled classification. that of normal intellectual capability. Using a Full Scale IQ of at least 85 as the normality criterion. the proportion not meeting the normality criterion increased to 41% (N=85J. Table 1 presents the means and standard deviations of Verbal, Performance, and Full Scale IQ's, as well as mean scaled scores for the 10 WISC-R subtests according to three classifications: (a) all 208 children, (b) the high IQ subgroup (Full Scale IQ of at least 76 and either a Verbal or Performance IQ of at least 90). and (c) the low IQ subgroup (children failing to meet the normality criterion). Performance IQ was consistently higher than Verbal IQ. This relationship held for the sample as a whole, where the Performance minus Verbal IQ discrepancy was 7.9 points
TABLE 1 Means and Standard Deviations for Verbal. Performance, and Full Scale IQ's, and for Subtest Scaled Scores According to Three Classifications Classificatjons
Total sample a Scale description
High IQ subgroupb
Low IQ subgroupC
Mean
SO
Mean
SO
Mean
SO
10 scores Full scale 10 Verbal 10 Performance 10
87.1 84.8 92.7
12.3 12.2 12.9
93.3 90.1 99.6
10.4 11.0 10.1
76.3 75.7 80.5
6.5 7.8 7.0
Verbal subtests Information Similarities Arithmetic Vocabulary Comprehension
6.6 8.0 7.2 7.9 8.2
2.7 2.9 2.2 2.7 2.6
7.5 9.0 7.8 8.9 9.1
2.5 2.7 2.2 2.5 2.6
5.0 6.3 6.2 6.3 6.6
2.2 2.3 1.8 2.2 1.8
9.7 8.9 8.6 10.2 7.3
2.6 3.0 2.9 2.8 2.9
10.8 10.1 9.6 11.4 8.0
2.2 2.5 2.7 2.4 2.9
7.7 6.8 7.0 8.2 6.1
2.0 2.8 2.3 2.3 2.4
Performance subtests Picture completion Picture arrangement Block design Object assembly Coding
a N =208, or 100% b N = 132, or 63% N = 76, or 37%
C
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(F=78.22, P < .0001); for a single classification repeated measures analysis of variance (ANOVA] (Winer, 1962); for the high IQ subsample, where the discrepancy was 9.5 points [F=64.99, p
J. MICHAEL COLEMAN PAUL R. DOKECKI EARL E. DAVIS Abstract: Over 200 school labeled learning disabled children enrolled in 23 classrooms for the learning disabled were administered the Wechsler Intelligence Scale for Children-Revised (WISC-R). Results indicated that 37% of the children tested did not meet the single most generally agreed upon requisite for learning disabled classification, which is that of a normal level of intellectual functioning. However, regardless of the relative level of intellectual functioning, mean Performance la's were significantly greater than .mean Verbal la's. Moreover, there was marked (and statistically reliable) heterogeneity among mean subtest scaled scores, although children with normal and subnormal intelligence exhibited similar patterns of WISC-R subtest scores.
352
P
,RES ENT research demonstrates the need to specify clearly the intellectual characteristics of children identified and labeled by the schools as learning disabled. Such specification is an important step in the process of designing and implementing effective and efficient service delivery systems for this major population. Although Black [1974) demonstrated that the decade from 1962 to 1972 witnessed an explosion of publications on the topic of learning disabilities [and that most of these reports were descriptive in nature), there is still little agreement on the intellectual attributes of learning disabled children. Wepman, Cruickshank, Deutsch, Morency, and Strother (1975) suggested that: There is little agreement either in medicine or in education on criteria for identifying children
MONTE D. SMITH is Assistant Professor of Psychology and Director of the Research and Evaluation Component of the Psychoeducational Agency/School System (PASS) Model Project, PAUL R. DOKECKI is Professor of Psychology, Director of the Program for Human Development Specialists, and Co-Principal Investigator for the PASS Model Project, and EARL E. DAVIS is Associate Professor of Special Education, Director of the Child Study Center, and Co-Principal Investigator of the PASS Model Project, George Peabody College for Teachers, Nashville, Tennessee; and J. MICHAEL COLEMAN is currently a doctoral student in Special Education, University of Virginia, Charlottesville. He was formerly coordinator of the PASS Project. The research reported herein was funded under US Office of Education, Bureau of Education for the Handicapped, (USOE/BEH) Contract No. OEC-O-74-8726. The opinions expressed, however, do not necessarily reflect the position or policy of USOE, and no official endorsement should be inferred. March 1977
with ... learning disabilities. Because the disabilities presented by these children are extremely heterogeneous, the search for any commonality ... has so far been fruitless. [p, 302)
In a similar vein, Bryan (1974) emphasized the multitude of characteristics which have been attributed to children labeled learning disabled, and suggested that this "mishmash of characteristics" has received little empirical support. She cited the following as negative attributes that have been mentioned as a problem in the learning disabled: hyperactivity, perceptual motor impairments, emotional lability, general coordination deficits, disorders of attention (short attention span, distractibility, perseveration), and impulsivity, disorders of memory and thinking, specific learning disabilities (reading, writing, spelling, arithmetic). disorders of speech and hearing, equivocal neurological signs, and electroencephalographic irregularities. There is much research on supposed deficiencies in auditory and visual processing claimed to be associated with learning disabled children. Yet, Bryan (1974) presented evidence that these most popular of learning disability stereotypes have not received substantial empirical support. Moreover, Hammill and Larsen (1974). in their review ofpsycholinguistically oriented investigations, indicated that the validity of this information processing approach to learning disabilities remains unproven. One generally claimed characteristic of the learning disabled child is normal intelligence. Both Ames (1968) and Bryan (1974). however, reported that approximately 25% of two samples of children labeled learning disabled were subnormal in intellectual functioning, and hence could ha ve been characterized more appropriately as educably mentally retarded. Even on the criterion that is most uniformly cited as a requisite for learning disability classification [i.e., normal intelligence), there is disagreement as to the point along the continuum of measured intellectual capacity that should serve to distinguish normal from subnormal intelligence. An IQ of 80 or 85 is often used as the cutting point, but Mercer (1975) recently argued that the normality cutting point should be 70. Recently, investigators have examined the Wechsler Intelligence Scale for Children (WISCj and the Wechsler Intelligence Scale for Children-Revised (WISC-R) subtest scaled score profiles of learning disabled children to determine if consistent patterns of Exceptional Children
scores distinguish them from normal children [Bannatyne, 1968. 1971. 1974; RugeI, 1974). Both Bannatyne and Rugel have reported distinct subtest profiles for learning disabled children, with pronounced "peaks" and "valleys" which are reputed to represent subcomposites of intellectual ability possibly associated with some aspects of learning disabilities, This investigation examined the WISC-R profiles of a large sample of school labeled learning disabled children with the objective of providing a composite intellectual profile in terms of Verbal IQ, Performance IQ, Full Scale IQ, and subtest scaled scores. The following specific questions were addressed: 1. What proportion of school labeled learning
disabled children failed to meet the criterion of normal intelligence? 2. Were there significant Verbal IQ versus Performance IQ discrepancies, and if so, did both relatively high IQ and low IQ children exhibit similar discrepancies? 3. Were there pronounced "peaks" and "valleys" in subtest scaled scores, as suggested by Bannatyne (1968, 1971, 1974) and Rugel (1974). or were the subtest scaled scores uniform in magnitude? 4. If subtest scaled score heterogeneity [i.e., distinct "peaks" and "valleys") was evident, were the patterns similar for relatively high IQ and low IQ children?
Method Participants
Participants were 208 children enrolled in 23 learning disability classrooms in a large metropolitan school system in the fall of 1974. Children in these 23 classrooms constituted approximately 79% of all children assigned to learning disability classes in the school system. The remaining 21% of learning disabled children in the school system were enrolled in two schools which declined to participate in the study. Although it was impossible to verify, it was felt that the children in these two schools were comparable. The learning disability referral procedure was uniform across the school system and schools with learning disability classrooms were feeder schools, with children bussed to the special classrooms from schools without learning disability classes. The children were independently verified as learning disabled by the school system prior to data collection. The children were 353
severely deficient academically, as indicated by an average discrepancy between obtained Metropolitan Achievement Test grade equivalents and age-appropriate grade placements of approximately 2 years. Children were not visually or hearing impaired. Participants had been enrolled in learning disability classes an average of 12 academic months. The age range was from 6 years, 3 months, to 12 years. 1 month (Mean =9 years, 9 months). The children were 76% male and 81% Caucasian. Procedure
The WISC-R was administered individually to children by trained personnel of the George Peabody College Child Study Center. The sample was divided into high and low IQ subgroups by using a normality criterion that embodied both an overall (Full Scale) minimum IQ (76) and a requirement that the child obtain either a Verbal or Performance IQ of at least 90.
Results
The normality criterion was not met by 76 children (37%). Thus. 37% of the participants did not meet the criterion most commonly accepted as a requisite of learning disabled classification. that of normal intellectual capability. Using a Full Scale IQ of at least 85 as the normality criterion. the proportion not meeting the normality criterion increased to 41% (N=85J. Table 1 presents the means and standard deviations of Verbal, Performance, and Full Scale IQ's, as well as mean scaled scores for the 10 WISC-R subtests according to three classifications: (a) all 208 children, (b) the high IQ subgroup (Full Scale IQ of at least 76 and either a Verbal or Performance IQ of at least 90). and (c) the low IQ subgroup (children failing to meet the normality criterion). Performance IQ was consistently higher than Verbal IQ. This relationship held for the sample as a whole, where the Performance minus Verbal IQ discrepancy was 7.9 points
TABLE 1 Means and Standard Deviations for Verbal. Performance, and Full Scale IQ's, and for Subtest Scaled Scores According to Three Classifications Classificatjons
Total sample a Scale description
High IQ subgroupb
Low IQ subgroupC
Mean
SO
Mean
SO
Mean
SO
10 scores Full scale 10 Verbal 10 Performance 10
87.1 84.8 92.7
12.3 12.2 12.9
93.3 90.1 99.6
10.4 11.0 10.1
76.3 75.7 80.5
6.5 7.8 7.0
Verbal subtests Information Similarities Arithmetic Vocabulary Comprehension
6.6 8.0 7.2 7.9 8.2
2.7 2.9 2.2 2.7 2.6
7.5 9.0 7.8 8.9 9.1
2.5 2.7 2.2 2.5 2.6
5.0 6.3 6.2 6.3 6.6
2.2 2.3 1.8 2.2 1.8
9.7 8.9 8.6 10.2 7.3
2.6 3.0 2.9 2.8 2.9
10.8 10.1 9.6 11.4 8.0
2.2 2.5 2.7 2.4 2.9
7.7 6.8 7.0 8.2 6.1
2.0 2.8 2.3 2.3 2.4
Performance subtests Picture completion Picture arrangement Block design Object assembly Coding
a N =208, or 100% b N = 132, or 63% N = 76, or 37%
C
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March 1977
(F=78.22, P < .0001); for a single classification repeated measures analysis of variance (ANOVA] (Winer, 1962); for the high IQ subsample, where the discrepancy was 9.5 points [F=64.99, p
