Throwing like a girl: a critique of past approaches and an illustrated proposal for a path forward.

backgroundThe phrase "Throwing like a girl" persists in popular culture and in scientific research as a trope about biological differences between males and females. In this review/theoretical paper I critically examine the support for the idea that sex differences in throwing style and force result from innate biological difference.

methodsThis article contains (1) a limited critical review of selected literature, (2) the application of a systems approach to the development of ball play that starts the study of throwing capacity as it develops in infancy and considers its emergence going forward and (3) a demonstration of this approach using qualitative descriptions of events (at ages 9-15 months) involving toddlers' first engagements in ball play.

resultsThe literature cited to support the claim that sex differences in throwing are a ubiquitous/universal feature of human children is weak. When I compared two toddlers over several months, starting at the time of their first ball throwing game, I learned that the boy and his mother played frequently even before he could walk. In contrast, the girl began ball play at an older age that coincided with her learning to walk. For 8 additional children, the boys started playing ball almost 2.5 months earlier than the girls, and all before they could walk.

conclusionsThe boy could raise the ball higher and throw it further at 13-14 months because he had practiced more from the more stable sitting and kneeling positions which allowed him to master double-handed overhead ball throwing before he could walk. The girl tried throwing the ball while walking unsteadily. Thus, when trying to raise the ball above her head, she often fell, and could not throw it very far. I conclude that to understand sex differences in embodied motor skills in children requires that we study the processes of motor learning beginning at birth.