Does stereopsis account for the link between motor and social skills in adults?

Background: Experimental and longitudinal evidence suggests that motor proficiency plays an important role in the development of social skills. However, stereopsis, or depth perception, may also play a fundamental role in social skill development either indirectly through its impact on motor skills or through a more direct route. To date, no systematic study has investigated the relationship between social skills and motor ability in the general adult population, and whether poor stereopsis may contribute to this association. This has implications for clinical populations since research has shown associations between motor abnormalities and social skills, as well as reduced depth perception in autism spectrum disorder and developmental coordination disorder. Methods: Six hundred fifty adults completed three validated questionnaires, the stereopsis screening inventory, the Adult Developmental Coordination Disorder Checklist, and the Autism Spectrum Quotient. Results: An exploratory factor analysis on pooled items across all measures revealed 10 factors that were largely composed of items from a single scale, indicating that any co-occurrence of poor stereopsis, reduced motor proficiency, and difficulties with social interaction cannot be attributed to a single underlying mechanism. Correlations between extracted factor scores found associations between motor skill and social skill. Conclusions: Mediation analyses suggested that whilst fine motor skill and coordination explained the relationship between stereopsis and social skill to some extent, stereopsis nonetheless exerted a substantial direct effect upon social skill. This is the first study to demonstrate that the functional significance of stereopsis is not limited to motor ability and may directly impact upon social functioning.