The Autism-Spectrum Quotient (AQ): Evidence from Asperger Syndrome/High-Functioning Autism, Males and Females, Scientists and Mathematicians

Currently there are no brief, self-administered instruments for measuring the degree to which an adult with normal intelligence has the traits associated with the autistic spectrum. In this paper, we report on a new instrument to assess this: the Autism-Spectrum Quotient (AQ). Individuals score in the range 0-50. Four groups of subjects were assessed: Group 1:58 adults with Asperger Syndrome (AS) or high-functioning autism (HFA); Group 2: 174 randomly selected controls. Group 3: 840 students in Cambridge University; and Group 4: 16 winners of the UK Mathematics Olympiad. The adults with AS/HFA had a mean AQ score of 35.8 (SD = 6.5), significantly higher than Group 2 controls (M = 16.4, SD = 6.3). 80% of the adults with AS/HFA scored 32+, versus 2% of controls.

Among the AS/HFA group, male and female scores did not differ significantly. The students in Cambridge University did not differ from the randomly selected control group, but scientists (including mathematicians) scored significantly higher than both humanities and social science students, confirming an earlier study that autistic conditions are associated with scientific skills. Within the sciences, mathematicians scored the highest. Test-retest and interrater reliability of the AQ was good. The AQ is thus a valuable instrument for rapidly quantifying where any given individual is situated on the continuum form autism to normality. Its potential for screening for autism spectrum conditions in adults of normal intelligence remains to be fully explored.

The AQ was designed to be short, easy to use, and easy to score. It comprises 50 questions, made up of 10 questions assessing 5 different areas: social skill, attention switching, attention to detail, communication and imagination. Approximately half the items were worded to produce a “ disagree” response, and half an “agree” response, in a high scoring person with AS/HFA.

Discussion
AS predicted, adults with AS/HFA scored significantly higher on AQ than matched controls. 80% scored above a critical minimum of 32+, whereas only 2% of controls did so. This demonstrates that the AQ has reasonable face validity, since the questionnaire purports to measure autistic spectrum traits, and people with a diagnosis involving these traits score highly.

We wish to underline that the AQ is not diagnostic, but may serve as a useful instrument in identifying the extent of autistic traits shown by an adult of normal intelligence. A score of 32+ appears to be a useful cut-off for distinguishing individuals who have clinically significant levels of autistic traits. Such a high score on the AQ however does not mean an individual has AS or HFA, since a diagnosis is only merited if the individual is suffering a clinical level of distress as a result of their autistic traits.