A comparison of WISC-IV and SB-5 intelligence scores in adolescents with autism spectrum disorder.
SB-5 boosts full-scale IQ while WISC-IV boosts verbal IQ in teens with autism, so pick one test and stick with it to track real change.
01Research in Context
What this study did
Alaimo et al. (2015) gave two IQ tests to teens with autism. One test was the WISC-IV. The other was the Stanford-Binet Fifth Edition (SB-5).
They wanted to see if the two tests gave the same scores for the same kids.
What they found
The tests tracked each other, but they did not match. SB-5 gave higher full-scale IQ scores. WISC-IV gave higher verbal IQ scores.
If you switch tests, the teen’s numbers move in opposite directions.
How this fits with other research
Lincoln et al. (1988) first showed the split profile: verbal beats visual-motor on Wechsler scales in high-functioning autism. T et al. now show the split can grow or shrink depending on which test you pick.
Chiang et al. (2014) pooled 52 studies and found people with Asperger’s always score higher on verbal than performance IQ. T et al. agree, but add that the size of the gap changes with the test brand.
Pathak et al. (2019) found higher IQ kids often have lower adaptive scores than expected. T et al. remind us that the IQ number itself is not fixed—it moves with the test, so the gap can look wider or smaller.
Why it matters
When you read an assessment report, check which IQ test was used. If the teen was tested with SB-5, expect a higher full-scale score. If the team used WISC-IV, expect a higher verbal score. Use this info when you set language and social goals. Do not assume a jump or drop in scores means real change—it may just be the test.
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02At a glance
03Original abstract
In autism spectrum disorders, results of cognitive testing inform clinical care, theories of neurodevelopment, and research design. The Wechsler Intelligence Scale for Children and the Stanford-Binet are commonly used in autism spectrum disorder evaluations and scores from these tests have been shown to be highly correlated in typically developing populations. However, they have not been compared in individuals with autism spectrum disorder, whose core symptoms can make testing challenging, potentially compromising test reliability. We used a within-subjects research design to evaluate the convergent validity between the Wechsler Intelligence Scale for Children, 4th ed., and Stanford-Binet, 5th ed., in 40 youth (ages 10-16 years) with autism spectrum disorder. Corresponding intelligence scores were highly correlated (r = 0.78 to 0.88), but full-scale intelligence quotient (IQ) scores (t(38) = -2.27, p = 0.03, d = -0.16) and verbal IQ scores (t(36) = 2.23, p = 0.03; d = 0.19) differed between the two tests. Most participants obtained higher full-scale IQ scores on the Stanford-Binet, 5th ed., compared to Wechsler Intelligence Scale for Children, 4th ed., with 14% scoring more than one standard deviation higher. In contrast, verbal indices were higher on the Wechsler Intelligence Scale for Children, 4th ed., Verbal-nonverbal discrepancy classifications were only consistent for 60% of the sample. Comparisons of IQ test scores in autism spectrum disorder and other special groups are important, as it cannot necessarily be assumed that convergent validity findings in typically developing children and adolescents hold true across all pediatric populations.
Autism : the international journal of research and practice, 2015 · doi:10.1177/1362361314554920