Executive functions predict restricted and repetitive behaviors in toddlers under 36 months old with autism spectrum disorder

Executive functions (EFs) and restricted and repetitive behaviors (RRBs) have been studied mainly in older individuals with autism spectrum disorder (ASD), while little is known about the relationship between EFs and RRBs in toddlers.The purpose of this study was to investigate the relationship between EFs and RRBs of toddlers with ASD symptoms. In addition, we tested whether EFs were predictive of RRBs in toddlers.Cross-sectional data were collected from parents of forty-five toddlers under 36 months old. The modified checklist for autism in toddlers (M-CHAT), the Gilliam autism rating scale (GARS-2), the behavior rating inventory of executive functioning-preschool version (BRIEF-P), and the repetitive behavior scale- revised (RBS-R) administered to parents.We found significant associations between EFs and (1) stereotyped behaviors, (2) self-injurious behaviors, (3) ritualistic behaviors, (4) sameness behaviors, (5) restricted behaviors, (6) compulsive behaviors, and (7) repetitive behaviors total score. Increases in EFs differences predicted an increase in RRBs.Our results indicate a link between EFs and RRBs. Future research on RRBs in ASD may benefit from focusing on specific EFs rather than general categories.