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

## TL;DR

This paper challenges the idea that boys and girls throw differently due to biology, suggesting instead that early play patterns and motor development explain observed differences.

## Contribution

The paper introduces a systems-based approach to studying throwing development from infancy, emphasizing the role of nurture and dynamic processes over binary sex differences.

## Key findings

- Boys began ball play earlier than girls, often before walking, enabling them to master throwing techniques sooner.
- Girls who started ball play later faced instability while learning to walk and throw simultaneously, affecting their throwing ability.
- Differences in throwing styles may stem from developmental timing and play frequency rather than innate biological sex differences.

## Abstract

The 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.

This 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.

The 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.

The 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.

The belief that boys and girls throw differently is widespread. The scientific findings supporting this belief, while numerous, vary greatly in terms of method and the age of the children studied. Furthermore, research projects are usually based on a two-fold binary paradigm: first that the important contrasts are between boys and girls; second that studies of variation in throwing form illuminate the degree to which nature compared to nurture contribute to reported differences. Here, I present an alternate paradigm—the analysis of motor skills as they first develop during infancy. This paradigm embraces nurture/nature and gender/sex as entangled and best understood as a dynamic whole; it also allows us to understand throwing form and skill as a continuum or spectrum rather than a binary construct. To offer a concrete instance, I describe the ball-playing activities of 10 infants aged 6–15 months and their mothers. The five boys all began to play active ball games with their mothers at the average age of 9.7 months. This early playing happened before they could walk, and they mastered stable two-handed overhead throwing from a sitting position. The girls and their mothers did not play ball until the babies averaged 12.1 months. Four out of five of the girls were learning to walk and throw at the same time, a condition of instability that made it difficult for them to fully raise the ball above their head without falling. We hypothesize that differences in timing and frequency of play events lead to continuous variability in the embodiment of throwing skills.