Evidence for a Broad Autism Phenotype

The broad autism phenotype implies the existence of a continuum ranging from individuals displaying almost no autistic traits to severely impaired diagnosed individuals. Recent studies have linked this variation in autistic traits to several domains of functioning. However, studies focusing on social–communicational traits associated with autism often suffer from two problems. First, they examine very specific behaviours, not taking the broad range of behaviours social functioning is comprised of into account. Second, most studies compare individuals scoring at the upper and lower extremes of the continuum, neglecting the natural range of autistic trait scores. The present study accommodates for these limitations by examining the link between self-reported autistic traits and a broad self-report measure of social functioning across individuals exhibiting a natural range of autistic traits. The results show that after tackling the discussed limitations, autistic traits still predict the amount of social behaviour people exhibit and the level of discomfort they experience when doing so. The amount of social behaviour and the experienced discomfort were especially related to autistic traits in the social and attention switching domains. The findings were still significant after controlling for the conceptual overlap with the social domain of the autism measure. These findings support the broad autism phenotype by showing how a continuous measure of autistic traits is related to a continuous measure of social functioning.