The Relationship of Age with the Autism-Spectrum Quotient Scale in a Large Sample of Adults

Lay Summary: Self-report questionnaires of autism characteristics are a potentially important resource for studying autism in adulthood. This study sought to provide additional information about one of the most commonly used self-report questionnaires, the Autism-Spectrum Quotient Scale (AQ), across adulthood. This study intended to determine if there is a relationship between scores on the AQ and age. Researchers also worked to identify which of the multiple different ways of scoring the AQ worked best across adulthood. Researchers collected data from over a thousand participants aged 18-97 years. Participants from three different age groups completed online surveys to self-report their levels of autism characteristics on the AQ. Researchers tested the relationship between AQ scores and age with six different commonly used ways to calculate AQ scores. Researchers used multiple statistical techniques to evaluate various measurement properties of the AQ. The results indicate that autism characteristics measured by the AQ are not strongly associated with age. Along with that, there is evidence that certain approaches to measuring of autism characteristics are consistent across age into late life and do not vary with demographic and autism-related factors. These results add to the growing evidence that self-reports of autism characteristics using the AQ in general samples are not strongly associated with age across adulthood. These findings also provide guidance about ways of scoring the AQ that work well through late life. While the AQ has a degree of relationship with autism diagnoses, this is far from perfect and has not been evaluated in the context of aging research. Therefore, findings from the present research must be carefully interpreted to be about autism characteristics not diagnoses. The sample was also limited in a number of other ways. As in any studies including a broad age range of individuals, the oldest participants are likely quite healthy, engaged individuals. This may particularly be the case given the higher mortality rates and health challenges seen with autism. Similarly, as with any self-report research, this research is limited to those individuals who could answer questions about their autism characteristics. The sample was also predominantly White and nonautistic. Finally, the research was limited to one point in time and so cannot tell us about how autism characteristics may change across adulthood. These findings support the potential for the AQ to be a useful tool for future research on autism in adulthood. For example, researchers can use measures such as the AQ to study how autism characteristics change over time or are associated with aging-related issues such as changes in physical health and memory. Such research may be able to provide a better understanding of how to support autistic individuals across adulthood.