The relationship between cognitive flexibility and restricted, repetitive behaviors in children with autism: parents' reports vs. cognitive task performance.

Cognitive flexibility (CF), a core component of executive functioning, is often impaired in children with autism and closely linked to restricted and repetitive behaviors and interests (RRBIs). This study examined CF in 43 young children with autism (ages 3-7) using both performance-based measures (DCCS) and parent-reported CF (BFRS-R). We investigated the associations between CF and higher-order versus lower-order RRBIs, assessed convergence between performance-based and parent-report CF measures, and evaluated the contribution of other executive function (EF) domains and autism-related symptoms. Results revealed that higher-order RRBIs (e.g., ritualistic routines, insistence on sameness) were consistently associated with CF deficits, whereas lower-order RRBIs (sensorimotor behaviors) showed nonsignificant associations. Additionally, strong convergence between performance-based and parent-reported assessment of CF, with accuracy-based switch cost emerging as the most sensitive and robust indicator of CF in early childhood. Regression analyses confirmed that higher-order RRBIs, working memory, and communication difficulties significantly accounted for variance in cognitive flexibility. Taken together, these findings provide a comprehensive understanding of the relationships among cognitive flexibility, RRBIs as well as executive functions, and communication in early childhood autism. The integration of performance-based and parent-report assessments highlights the complementary value of multi-method approaches and offers a foundation for refining future assessment strategies and developmental research.