Brief report: concurrent validity of the Leiter-R and KBIT-2 scales of nonverbal intelligence for children with autism and language impairments.
Two quick IQ tests can paint different pictures of the same child—always cross-check before big decisions.
01Research in Context
What this study did
Scattone et al. (2012) gave the same kids two quick IQ screens.
They used the Leiter-R and the KBIT-2 nonverbal scales.
All children had autism or other language problems.
The team wanted to know if the two tests give the same score.
What they found
The overall correlation was moderate.
Yet four in ten children scored ten points higher or lower on one test.
Some gaps reached twenty points.
A ten-point swing can move a child from typical to delayed, or vice-versa.
How this fits with other research
Phillips et al. (2014) saw the same warning.
They compared Leiter-R to the PPVT-4 in kids with Down syndrome.
Switching tests changed whether groups looked equal or not.
The two papers agree: Leiter-R is handy, but not interchangeable with other screens.
Takahashi et al. (2023) add a wider lens.
Their meta-analysis shows large motor gaps in kids with ID.
If you pick the wrong IQ test and mis-match groups, you might blame motor delays on cognition, or miss them entirely.
Why it matters
Before you write goals or place a child, give at least two brief IQ screens.
If the scores differ, use the lower one for services and the higher one for strengths.
This habit keeps you from under-estimating or over-estimating ability.
It also makes your data line up when you read later studies that used either tool.
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02At a glance
03Original abstract
The concurrent validity of the KBIT-2 Nonverbal IQ and Leiter-R Brief IQ was evaluated for two groups of children: those with high functioning autism and those with language impairments without autism. Fifty-three children between the ages of 4 and 13 years of age participated in the study. The correlation between the scales was large (r = .62) and no statistical difference was found between the means. However, large intraindividual differences were found for 11 children who received scores at least 10 points higher on the Leiter-R Brief IQ, 5 of those scored beyond 20 points higher than nonverbal scores on the KBIT-2. Conversely, 11 children scored at least 10 points higher on the KBIT-2 than on the Leiter-R with 4 of those scoring 20 points higher. These findings highlight the importance of using multiple measures when assessing individuals with autism or language disorders.
Journal of autism and developmental disorders, 2012 · doi:10.1007/s10803-012-1495-y