Better movers, better friends? A test for the environmental stress hypothesis in typically developing primary school children.

Relations between children's motor skills and internalizing problems are poorly understood. The environmental stress hypothesis (ESH), originally developed for motor-impaired children, may provide understanding, yet has been scarcely examined in typically developing children. Therefore, we examined: (1) relations between children's motor skills and internalizing problems; (2) the role of secondary stressors, specifically interpersonal conflicts and externalizing problems; and (3) the role of personal resources, namely, prosocial behaviour and social self-efficacy (SSE). About 1154 Dutch primary school children (mean age 9.0 years, 50.0% boys) participated. Multilevel structural equation models showed that children's motor skills were related to internalizing problems, with a weak indirect relation via interpersonal conflicts. SSE had a weak indirect relation with internalizing problems. Prosocial skills (personal resource) and externalizing problems (secondary stressor) did not mediate relations between motor skills and internalizing problems. The ESH seemed applicable in typically developing children, although relations were weaker than for motor-impaired children.