Motor, cognitive, and socio-cognitive mechanisms explaining social skills in autism and typical development.

Challenges in social functioning are considered a core criterion for diagnosing autism. Although motor skills, executive functioning (EF), and theory of mind (ToM) abilities independently affect social challenges and are interconnected, these abilities' shared contribution to the explanation of social functioning in autism remains under-investigated. To address this disparity, we examined the motor, EF, and ToM abilities of 148 autistic and non-autistic youth (ages 6-16 years), evaluating these variables' impact on social ability and their interconnections. Our mediation model exploring the contribution of motor, EF, and ToM skills explained 85% of the variance in social functioning (Social Responsiveness Scale-SRS-2). Analysis yielded a direct path from study group to SRS-2-social (typically developing-TD > autistic) and two main parallel indirect joint paths: (a) Group ➔ motor ➔ EF ➔ SRS-2-social; and (b) Group ➔ motor ➔ ToM ➔ SRS-2-social. In two secondary indirect paths, autistic children showed lower motor skills, which in turn explained their higher EF and/or ToM impairment, which in turn explained their higher social skills impairment. Put differently, our results suggest that better EF and TOM proficiency may compensate for poorer motor skills. Findings also indicated that the collective impact of motor, EF, and ToM skills on social functioning, along with the mediating role played by EF and ToM on the social-motor linkage, may contribute to understanding individual differences in the social functioning of autistic children. These conclusions call for the inclusion of motor, EF, and ToM activities into daily practices to facilitate social functioning.