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.