Restricted and Repetitive Behavior Subtypes Show Distinct Associations with Adaptive Functioning in Autistic Children

Restricted and repetitive behaviors (RRBs) are a core feature of autism spectrum disorder, yet their distinct impacts on adaptive functioning remain unclear. Adaptive functioning, including communication, socialization, and daily living skills, is critical for quality of life in autistic children. Here we performed exploratory factor analysis of the Repetitive Behavior Scale-Revised in 167 autistic children aged 3-12 years, identifying three RRB subtypes: sameness/ritualistic/restricted behaviors, stereotypic/self-injurious behaviors, and compulsive behaviors. In primary models adjusting for age and sex, sameness/ritualistic/restricted behaviors predicted lower socialization, whereas stereotypic/self-injurious behaviors predicted lower communication and daily living skills. In a sensitivity analysis additionally adjusting for IQ, in the subset of children with available cognitive data, only sameness/ritualistic/restricted behaviors remained a significant predictor across all three domains. These findings suggest that not all RRB subtypes are equally associated with adaptive functioning, underscoring the need to differentiate RRBs when designing interventions. Understanding subtype-specific associations may guide strategies that address behaviors hindering adaptive outcomes while considering those with potential regulatory functions.