Autism Spectrum Quotient (AQ)

Description

The Autism Spectrum Quotient (AQ) is a 50 item self-report measure used to assess traits of autism in adults and adolescents aged 16 years and over. The measure is suitable for men and women who have normal intellectual functioning. The AQ measures five symptom clusters important in understanding the profile of strengths and weaknesses for individuals with Autism:
- social skill
- attention switching
- attention to detail
- communication
- imagination.

The AQ is intended to be used to screen for autism spectrum and may make up a component of a thorough diagnostic assessment. A score above the proposed cutoff of 29 highlights significant traits of autism.

Validity

The AQ was developed by Baron-Cohen and colleagues (2001). They administered the scale to adults with DSM-IV classified Asperger syndrome (AS) or high-functioning autism (HFA) (Autism sample, N = 58) and to a control sample of randomly selected individuals from the community (N = 174). Psychometric analysis indicated adequate inter-rater and test-retest reliability. Internal consistency was moderate to high.

A cutoff score of 32+ was suggested in the original Baron-Cohen and colleagues (2001) article, and was found to distinguish the Autism Sample from the control Community Sample. Subsequent analysis by Broadbent and colleagues (2013) found that a cutoff score of 29+ had a 14.4% false negative rate, and a less than 1% false positive rate. This analysis suggest the optimal cutoff score is 29.

Data for gender related norms are provided for the sample of adults with autism and the community sample (Baron-Cohen et al., 2001).
Men with autism have an average score of 35.1 (SD = 6.9), while the mean score for women with autism is 38.1 (SD = 4.4).

Interpretation

Items are summed to obtain an overall total score and scores for each of the five subscales. Higher scores indicate responses that are more consistent with autism traits.

A total score of 29 or more is indicative of clinically significant autism traits (Broadbent, et al., 2013). Using the cut-off score of 29 has a false positive rate of 1%, however will fail to identify 14.4% of people who actually do meet the diagnostic criteria for DSM-5 defined Autism Spectrum Disorder.

The total score and subscale scores are also represented as percentiles for comparison to gender specific norms for the Autism Sample and the Community Sample (Baron-Cohen et al., 2001).

Percentiles compared to the Autism Sample compares the respondent's score to people who have been diagnosed with Autism, where a percentile of 50 indicates typical scores for someone with Autism.

For men, a total score of 29 corresponds to a percentile compared to the male autism sample of 18.9 and a percentile of 95 compared to the male community sample.

For women, a total score of 29 corresponds to a percentile compared to the female autism sample of 1.9 and a percentile of 99.1 compared to the female community sample.

Five subscales are presented, with higher scores on each subscale indicate more neurodivergence in each area. For example, high scores on social skills indicates more social skills deficits, and high scores on attention to detail indicates an atypical focus on details. The following items are summed to obtain scores for each of the subscales:
- Social skill: items 1,11,13,15,22,36,44,45, 47,48
- Attention switching: items 2,4,10,16,25,32,34, 37,43,46
- Attention to detail: items 5,6,9,12,19,23,28, 29,30,49
- Communication: items 7,17,18,26,27,31,33, 35,38,39
- Imagination items: 3,8,14,20,21,24,40,41,42,50

Developer

Baron-Cohen, S., Wheelwright, S., Skinner, R., Martin, J., & Clubley, E. (2001). The autism-spectrum quotient (AQ): Evidence from asperger syndrome/high-functioning autism, males and females, scientists and mathematicians. Journal of autism and developmental disorders, 31(1), 5-17.