Social Independence Skills in Autistic Adolescents and Adults : Analysis of the Structure of Intelligence (WISC-R)

Abstract

In the test battery that the present authors had designed to evaluate the social skills and behavior of autistic adolescents and adults, the WISC-R is useful as a screening test. The present study aimed to analyze the structure of the intelligence of such persons. Subjects were 59 autistic adolescents and adults (51 males and 8 females), between 15 and 35 years old. Twelve subtests of the WISC-R were administered to all subjects. The raw scores were factor analyzed according to the Varimax solution, using the squared multiple correlation method. The factor analysis revealed three factors: I. Verbal Comprehension, II. Perceptual Organization, and III. Freedom from Distractibility. This replicated the results reported by Kaufman (1975). The factor loadings on factors I and III were specific to the autistic adults. A cluster analysis (Q mode) was then done on the basis of the factor scores. Nine clusters were extracted: subjects in six clusters had full-scale IQs below 35; the intelligence measures for subjects in five clusters showed a discrepancy between verbal and performance intelligence (VIQ/PIQ discrepancy). The response traits were described with regard to verbal, perceptualmotor, and adaptive levels. The results were as follows: 1. Some cases were found to have relatively high IQs (full-scale IQ above 75). 2. Epileptic seizures were often combined with severe mental retardation. 3. There was a high correlation between verbal acceptance and task performance. 4. Three subtests (#11, Digit Span; #6, Block Design; and #8, Object Assembly) significantly distinguished the clusters.