Validation of the English version of the Autism-Spectrum Quotient in an English-speaking Singaporean sample

The Autism-Spectrum Quotient (AQ) measures the degree of autistic traits in clinical and non-clinical samples and has been validated in various countries and languages. However, the AQ has not been validated in Singapore, an Asian country whose population speaks predominantly English. Although previous validation studies have examined the distribution of scores, internal consistency, test-retest reliability and construct, convergent and discriminant validities in Asian countries using translated versions of the AQ and generally shown a suitable structure of the AQ, other studies testing cultural differences of the AQ have provided inconsistent results about whether differences exist in scores between Western and Asian samples. Additionally, while prior literature has consistently documented sex differences in AQ scores, findings about the relationship between personality traits and friendship quality with autistic traits have been mixed. The aim of the current study was to validate the psychometric properties of the original English AQ in a non-clinical Singaporean sample and compare their mean AQ scores to previous Western samples. In this study, psychometric properties of the original English AQ were assessed in 113 Singaporean adults (47M/66F; Mean age = 37.78; SD = 14.52) with no clinical diagnoses. They completed the AQ, the Friendship Questionnaire (FQ) and the short Big Five Inventory, with a subsample completing the AQ twice within three to six months. Results showed that AQ scores were normally distributed and the AQ had satisfactory internal consistency and test-retest reliability and it demonstrated construct, convergent and discriminant validities. Higher AQ scores were related to lower friendship quality and extraversion and higher neuroticism. The mean AQ scores of the Singaporean sample did not differ to that reported in original British sample. Together, present findings showed the original English AQ to be reliable for measuring the degree of autistic traits in a non-clinical Singaporean sample, producing comparable AQ scores and showing the same relationships to other social and personality measures and the same sex differences as has been reported in English samples. This supports the use of the AQ in Singapore for clinical and research purposes and suggests that the measurement of autistic traits in some Asian cultures is comparable to that reported in Western cultures.