It has been strongly argued that atypical cognitive processes in autism spectrum disorder (ASD) contribute to the expression of behavioural symptoms. Comprehensive investigation of these claims has been limited by small and unrepresentative sample sizes and the absence of wide-ranging task batteries. The current study investigated the cognitive abilities of 100 adolescents with ASD (mean age = 15 years 6 months), using 10 tasks to measure the domains of theory of mind (ToM) and executive function (EF). We used structural equation modelling as a statistically robust way of exploring the associations between cognition and parent-reported measures of social communication and restricted and repetitive behaviours (RRBs). We found that ToM ability was associated with both social communication symptoms and RRBs. EF was a correlate of ToM but had no direct association with parent-reported symptom expression. Our data suggest that in adolescence ToM ability, but not EF, is directly related to autistic symptom expression
