Both environmental and biological factors have been cited to explain large gender differences in throwing. Because differences are observed as early as three years, some researchers have suggested biological differences may be a primary factor (Nelson et al., 1986). To explore the contribution of these factors more carefully, three groups of children, 7-8 years, 9-10 years, and 11-12 years, were videotaped performing ten forceful overarm throws each with their dominant and nondominant hands. Resultant ball velocities were computed across all trials for each hand. Five trials for each arm, for each participant were categorized using Roberton’s (Roberton & Halverson, 1984) movement components for the overarm throw. Overall significant age differences were obtained for ball velocities for both dominant and nondominant arms, but gender differences were demonstrated only for the dominant arm. Ball velocity differences for the nondominant arm were not evident. Minimal differences in form occurred for the nondominant arm. When the nondominant arm exhibited coordination patterns and performances typical of an unpracticed performer, we suggest that nonbiological factors are important in explaining the large gender differences in throwing widely noted in the literature.
The authors thank the participants of this investigation, without whom this research would have been impossible. In addition, we thank three anonymous reviewers for their helpful comments. Their feedback was invaluable in clarifying our thinking.