Assessment & Research

Further evidence on the factorial structure of the Autism Spectrum Quotient (AQ) for adults with and without a clinical diagnosis of autism.

Lau et al. (2013) · Journal of autism and developmental disorders 2013
★ The Verdict

Use the 39-item AQ with five factor scores for quicker, clearer autism-trait profiles in adults.

✓ Read this if BCBAs who assess adults for autism or run social-skills groups for bright clients.
✗ Skip if Clinicians who only work with young children or already use gold-standard diagnostic tools.

01Research in Context

01

What this study did

Pow and colleagues took the 50-item Autism-Spectrum Quotient (AQ) and ran a fresh factor analysis on adults with and without autism.

They wanted a shorter, cleaner set of questions that still split the two groups.

02

What they found

The team kept 39 items that grouped into five clear factors: Sociability, Social Cognition, Interest in Patterns, Narrow Focus, and Resistance to Change.

The new AQ-39 gave reliable scores and still showed higher numbers for adults with ASD than for typical adults.

03

How this fits with other research

This paper updates the original 50-item AQ from Roane et al. (2001). The old version worked, but the new one trims the fat and gives you trait profiles instead of one big total.

do Egito et al. (2018) ran a similar factor study in Brazil and got only three factors, not five. The difference likely comes from language and culture, not a flaw in either study.

Diz et al. (2011) later used the refined five-factor scores to show that typical adults with higher AQ traits slip on attention tasks under heavy load—proof the shorter scale still predicts real behavior.

04

Why it matters

If you screen adults for autism traits, switch to the 39-item AQ. You save clients 11 questions and gain five clear trait scores instead of one bulky total. Those profiles can guide your interview: high Resistance to Change calls for extra structure, high Narrow Focus hints at visual supports. The scale is free and fast—print it, score it, and you have a roadmap for next steps.

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Print the AQ-39, give it to your next adult client, and note the five factor scores to plan supports.

02At a glance

Intervention
not applicable
Design
other
Sample size
455
Population
autism spectrum disorder, neurotypical
Finding
not reported

03Original abstract

The Autism Spectrum Quotient (AQ) has been widely used for measuring autistic traits however its factor structure has been primarily determined from nonclinic populations. This study aimed to establish an internally coherent and reliable factor structure for the AQ using a sample of 455 Australian adults of whom 141 had autism spectrum disorder (ASD) diagnoses. Principal component analysis revealed a 39-item questionnaire with five-factors: Sociability, Social Cognition, Interest in Patterns, Narrow Focus and Resistance to Change. The revised AQ-39 had sound goodness-of-fit indices, good-to-excellent internal consistency and test-retest reliability, and scores for ASD and non-ASD participants were significantly different. The AQ-39 may be useful in screening and for guiding the focus of therapy.

Journal of autism and developmental disorders, 2013 · doi:10.1007/s10803-013-1827-6