Assessment & Research

Brief report: performance pattern differences between children with autism spectrum disorders and attention deficit-hyperactivity disorder on measures of verbal intelligence.

Zayat et al. (2011) · Journal of autism and developmental disorders 2011
★ The Verdict

Autism often prints a clear Similarities > Vocabulary > Comprehension slide on WISC-IV—use that pattern as a fast triage tool.

✓ Read this if BCBAs who conduct or interpret cognitive testing for school-age children with suspected autism or ADHD.
✗ Skip if Clinicians who only use nonverbal assessments or work exclusively with infants.

01Research in Context

01

What this study did

The team gave the WISC-IV verbal subtests to kids with autism and to kids with ADHD.

They looked at how each group scored on Similarities, Vocabulary, and Comprehension.

The goal was to see if the two diagnoses leave different "fingerprints" on the test.

02

What they found

Children with autism slid down the three subtests in order: Similarities strongest, Vocabulary lower, Comprehension lowest.

Children with ADHD did not show this tidy step-down pattern.

The pattern could help clinicians decide which label to explore first.

03

How this fits with other research

Coolican et al. (2008) saw the same nonverbal-over-verbal tilt in autism using the Stanford-Binet, so the WISC-IV pattern is not a one-off.

Cramm et al. (2009) found that kids whose nonverbal tops verbal also lack inner speech; Maya’s step-down fits that group, hinting the weak Comprehension score may flag absent self-talk.

Mundy et al. (2016) compared autism and ADHD too, but on memory during joint attention. Their paper and this one together show the two diagnoses differ in both social-cognitive and verbal domains, strengthening the case for separate assessment tracks.

04

Why it matters

If you test a child and see Similarities > Vocabulary > Comprehension, think autism first. Pair this red flag with social and repetitive-behavior data before you consider ADHD. The quick check can shorten the road to the right referral and save re-testing later.

Free CEUs

Want CEUs on This Topic?

The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.

Join Free →
→ Action — try this Monday

After you score any WISC-IV, jot the three verbal scaled scores in order; if they drop like stairs, add autism-specific social probes to your assessment plan.

02At a glance

Intervention
not applicable
Design
other
Population
autism spectrum disorder, adhd
Finding
not reported

03Original abstract

Performance patterns on verbal subtests from the WISC-IV were compared between a clinically-referred sample of children with either autism spectrum disorders (ASD) or attention deficit/hyperactivity disorder (ADHD). Children with ASD demonstrated a statistically significant stepwise pattern where performance on Similarities was best, followed by Vocabulary, then Comprehension. Although children with ASD and ADHD share multiple behavioral features, this pattern was not observed for those with ADHD. Greater deficits in social reasoning and verbal formulation for children with ASD (compared to ADHD) are hypothesized to account for this observed difference in their performance pattern. Clinical implications, including use of this identified pattern in combination with other symptoms suggestive of ASD in referral decision making are discussed.

Journal of autism and developmental disorders, 2011 · doi:10.1007/s10803-011-1207-z