Comparison of the Leiter International Performance Scale-Revised and the Stanford-Binet Intelligence Scales, 5th Edition, in children with autism spectrum disorders.
Leiter-R can inflate IQ scores in kids with ASD, so always pair it with another test and explain the range.
01Research in Context
What this study did
The team pulled 47 clinic charts of kids with ASD .
Each child had taken two IQ tests: the Leiter-R (no talking needed) and the Stanford-Binet 5 (some verbal parts).
They compared the scores to see if the tests told the same story.
What they found
The Leiter-R gave an average IQ 21 points higher than the SB5.
Younger kids had the biggest gaps.
One test often labeled a child as having intellectual disability while the other did not.
How this fits with other research
Phillips et al. (2014) saw almost no gap between Leiter-R and DAS-II in deaf preschoolers.
The difference? Their kids had ASD plus language issues, not just hearing loss.
Hirota et al. (2018) remind us that only a few tools hold up across studies—so picking the right test matters.
Together the papers warn: same test name does not promise same result in different groups.
Why it matters
When you read an old report, check which IQ test was used. If you need a fresh plan, give both a non-verbal and a mixed battery. Share the score range, not just the number, with teachers and parents so everyone knows the picture may shift.
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02At a glance
03Original abstract
A review of hospital records was conducted for children evaluated for autism spectrum disorders who completed both the Leiter International Performance Scale-Revised (Leiter-R) and Stanford-Binet Intelligence Scales, 5th Edition (SB5). Participants were between 3 and 12 years of age. Diagnoses were autistic disorder (n = 26, 55%) and pervasive developmental disorder-not otherwise specified (n = 21, 45%). Analysis showed that the full sample received significantly higher scores on the Leiter-R than SB5 (mean discrepancy of 20.91 points), specific diagnosis was not a significant factor, and younger children had a larger discrepancy between tests. These analyses strongly suggest that the Leiter-R and the SB5 may not be equivalent measures of intellectual functioning in children with autism spectrum disorders, and that use of one or the other exclusively could lead to misclassification of intellectual capacity.
American journal on intellectual and developmental disabilities, 2013 · doi:10.1352/1944-7558-118.1.44