Linking cognitive flexibility, planning, and autistic traits: The mediating role of cognitive abilities.

Autistic children often face cognitive challenges, particularly in executive functions (EFs). Previous research has explored the relationship between EFs and autistic traits, including social abilities and restricted and repetitive behaviours (RRBs). While some consistencies emerge from ecologically valid ratings, results from performance-based measures and studies combining lab tasks with parent reports remain inconsistent. This study investigated associations between EFs and autistic traits, focusing on the mediating role of cognitive abilities. We assessed 110 autistic participants aged 4-17 years (33 with IQ <85; 77 with IQ ≥85) using a comprehensive neuropsychological battery, including the Weschler Intelligence Scale for Children (WISC-IV), performance-based EF tasks (WCST, TOL), clinician ratings (ADOS-2), and parent-reported measures (SRS-2). Results showed significant links between cognitive flexibility and clinician-observed RRBs, and between planning skills and parent-reported autistic traits. Notably, cognitive abilities mediated the relationships of cognitive flexibility and planning with clinician-rated social-communication skills. Lower IQ participants performed worse on most EF measures, except for errors in shifting and planning task timing. Clinicians reported lower social scores only in the lower IQ group. These findings reveal inconsistencies in convergence between performance-based EF measures and autistic traits from parent and clinician reports. Importantly, cognitive abilities play a significant role in clinical assessments of EF and socio-communication, highlighting the need for more sensitive and ecologically valid neuropsychological tools. Conversely, cognitive skills did not influence clinician-rated RRBs or parent reports, suggesting these behaviours may be independent of broader cognitive abilities.