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 162 autistic children aged 3–12 years, identifying three RRB subtypes: sameness/ritualistic/restricted behaviors, stereotypic/self-injurious behaviors, and compulsive behaviors. Regression analyses controlling for age, sex, and IQ revealed that only sameness/ritualistic/restricted behaviors consistently predicted lower adaptive functioning across domains. Notably, while stereotypic/self-injurious behaviors predicted communication and daily living skills in initial models, only the sameness/ritualistic/restricted factor remained a robust predictor after accounting for IQ. These findings suggest that not all RRB subtypes equally affect daily 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.