Brief Report: Sex Differences in ASD Diagnosis—A Brief Report on Restricted Interests and Repetitive Behaviors

Previous research found repetitive and restricted behaviors (RRBs) were less predictive of Autism Spectrum Disorder (ASD) in females, indicating the diagnostic construct may not adequately describe RRB presentations in females. This mixed-methods study investigated the female presentation of RRBs, namely restricted interests, in a clinic sample of 125 participants (n = 40 female; ages 2–83 years; 75 ASD). RRB severity did not differ between sexes, t = 1.69, p = 0.094, though male participants scored higher on the Restricted Behavior subscale. Qualitatively, females demonstrated a narrower range of restricted interests and expressed them in a socially oriented manner compared to males. The results suggest unique quantitative and qualitative sex differences in RRB profiles that could shed light on the female ASD phenotype.