Comparison of cognitive deficits among autistic and retarded children on the Arthur Adaptation of the Leiter International Performance Scales.
Autistic kids often ace concrete Leiter items but stumble on formal ones— check the subtests before you bank on the full-scale IQ.
01Research in Context
What this study did
The team gave the Arthur Adaptation of the Leiter scale to three groups: autistic children, children with mental retardation, and neurotypical children.
They matched the groups by mental age, not calendar age.
Then they compared how each group handled concrete versus formal discrimination tasks.
What they found
Autistic kids scored higher than their peers on concrete tasks like matching pictures.
The same kids scored lower on formal tasks like sorting by rules.
The other two groups showed no split— their scores stayed flat across both task types.
How this fits with other research
Magiati et al. (2001) later showed that simply picking a different test can swing an autistic preschooler’s IQ by 20 points— echoing this paper’s warning to look beyond the total score.
Courchesne et al. (2019) found that strength-based tests reveal more accurate abilities in minimally verbal autistic preschoolers, extending the idea that the right task format matters.
Mottron (2004) adds that common quick-screen tools like PPVT or Raven matrices overestimate IQ compared with Wechsler scales in high-functioning autistic kids— another reason to inspect the task type before you trust the number.
Why it matters
Your autistic learner’s Leiter score might look average, yet hide a concrete-formal split. Always check sub-test patterns, not just the total. Pick strength-based or concrete formats for teaching new skills, and use formal tasks only when you want to train rule-governed thinking. This small shift can cut frustration and give you a clearer picture of real ability.
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02At a glance
03Original abstract
Seven autistic, 7 mentally retarded, and 11 normal children were matched for mental age according to the Arthur Adaptation of the Leiter International Performance Scale (AALIPS). On the basis of two constructs, concrete discrimination and formal discrimination, all of the tasks in the AALIPS were grouped into two indices and six scales. Group comparisons were made on the indices and the scales. The results showed that (a) the performance of the autistic children was better than that of the other two groups on concrete discrimination tasks, (b) the performance of the autistic children was poorer than that of the other two groups on formal discrimination tasks, and (c) the quality of the autistic children's performance decreased as task requirements for formal discrimination increased. This pattern was not observed among the mentally retarded or normal children. A further analysis for sex showed significant main effects for sex on the formal discrimination tasks. The application of these results to test interpretation and future research is discussed.
Journal of autism and developmental disorders, 1981 · doi:10.1007/BF01531616