Analysis of WISC-III, Stanford-Binet:IV, and academic achievement test scores in children with autism

Nonverbal IQs were greater than verbal IQs for young children (3-7 years of age) on the Stanford-Binet:IV (n = 53). However, WISC-III verbal and nonverbal IQs were similar for older children, 6-15 years of age (n = 63). Stanford-Binet:IV profiles were generally consistent for the low-IQ (<80) and high-IQ (≥80) groups, with high scores on visual matching tests (Bead Memory and Quantitative Reasoning). The low- and high-WISC-III IQ groups both performed well relative to IQ on tests of lexical knowledge (Similarities, Information, and Vocabulary), but not on language comprehension and social reasoning (Comprehension). The low-IQ group did best on visuo-motor subtests (Object Assembly and Block Design), but the high-IQ group did not. The high-IQ group had significantly low scores on the Digit Span, Arithmetic, Coding, VMI, and WIAT Written Expression tests, suggesting attention and writing weaknesses.