Defining the intellectual profile of Asperger Syndrome: comparison with high-functioning autism.
Group IQ trends can hint at Asperger versus high-functioning autism, but wide overlap forces you to treat the learner, not the label.
01Research in Context
What this study did
Ghaziuddin et al. (2004) compared IQ scores of kids with Asperger Syndrome and kids with high-functioning autism.
They used the WISC or WAIS-R to get verbal IQ, performance IQ, and subtest scores for each child.
The goal was to see if a clear IQ pattern could tell the two diagnoses apart.
What they found
The Asperger group had higher verbal IQ and better vocabulary scores than the high-functioning autism group.
Still, scores overlapped a lot, so one kid's profile could not safely separate the labels.
In short, the group trend exists, but single-case use is shaky.
How this fits with other research
Porter et al. (2008) ran a near-copy study with adults and the newer WAIS-III. They found no verbal-performance IQ split, but they did find unique subtest lows: slow processing speed in high-functioning autism and weak digit span in Asperger. The change in test and age may explain the different outcome, so the papers do not truly clash.
Sharma et al. (2012) reviewed decades of studies and concluded that DSM-IV criteria for Asperger and autism overlap too much for clean sorting. Their view frames Mohammad's IQ overlap as one more sign that the labels blend together.
Narzisi et al. (2013) stepped past IQ and gave a full neuropsych battery. They showed that, beyond IQ, most cognitive domains are weak in high-functioning ASD except visuospatial skills. This widens Mohammad's IQ focus into a broader map of strengths and needs.
Why it matters
When you read an assessment report, a big verbal-performance split can nudge you toward an Asperger picture, yet heavy overlap means you should plan interventions for the learner's unique skill set, not for the label. Pair IQ data with subtest lows highlighted by Porter et al. (2008) and add broader neuropsych data from Narzisi et al. (2013) to get a full view of where support is needed.
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02At a glance
03Original abstract
Asperger syndrome (AS) is a disorder of early childhood characterized by autistic social deficits, subtle communication impairment, and excessive isolated interests. There is no history of language delay or of mental retardation. Despite its increasing popularity as a distinct condition, its diagnostic validity remains uncertain. It is still unclear to what extent AS differs from autism with normal intelligence sometimes referred to as high-functioning autism (HFA). However, some reports have suggested that persons with AS possess a distinct profile on tests of intelligence characterized by a high verbal IQ and a low performance IQ, whereas in most cases with HFA, the pattern is reversed. Since few studies have directly compared AS subjects with HFA controls using unmodified diagnostic criteria and standardized measures of assessment, in this report we compared 22 AS subjects with 12 HFA controls, matched on age, sex and level of intelligence. As a group, subjects with AS showed a higher verbal IQ and higher scores on information and vocabulary subtests than those with HFA. However, scores of several AS and HFA subjects showed a mixed pattern. Implications of these findings are discussed in the context of the validity of Asperger Syndrome.
Journal of autism and developmental disorders, 2004 · doi:10.1023/b:jadd.0000029550.19098.77