Parental hand preference and manual functional asymmetry in preschool children.

Hand preference and hand skill in 1150 normal children between 3 and 6 years of age and hand preference of their parents were assessed to study the effect of parental hand preference on different dimensions of manual asymmetry in children. Children hand skill was measured with a computerized version of the Peg Moving Task which allowed us to split the overall performance into two components, a "transport time" and a "search time." Paternal and maternal left-handedness was significantly related to child left-handedness. Both components of hand skill asymmetry were reduced with mother's left-handedness. and one component (search time) with father's left-handedness. A significant impact of paternal and preference on child hand skill asymmetry, after controlling for child hand preference, was observed. When this analysis was limited to strong right-handed children, a greater paternal effect on child hand skill emerged. These results show the usefulness of performance tasks in detecting parent-child associations concerning manual functional asymmetry.