We’ve all read some of the discussions about differences in men’s and women’s brains, but the case of throwing overhand offers a cautionary tale about thinking we’ve found something inherent in being male or female. The danger is that we accept too quickly observed differences without digging a bit deeper into their variation and potential causes. In the United States, most of our readers will have run across the idea that women throw like, well, … girls.In fact, the empirical gulf between average throwing ability in men and women is huge (just as it is symbolically important), dwarfing virtually any other measurable difference between the sexes, even things like aggression, frequency of masturbation, attitudes towards casual sex, and spatial abilities on paper-and-pencil tests.
Janet Shibley Hyde, one of the leading proponents of the ‘gender similarity hypothesis,’ concedes that there are some marked differences between men and women, singling out throwing ability as the most pronounced among them (2007: 260; see also 2005).
Thomas and French (1985: 266 & 276), in a meta-analysis reviewing all available research on sex differences in throwing, found that the gap stood at 1.5 standard deviations at three years of age, and increased over time, widening to between three and five standard deviations by puberty. By contrast, the much discussed ‘math gap’ between boys and girls, in Hyde’s meta-analysis of 48 studies, was a +0.08 on problem solving and +0.16 on national math tests (Hyde 2005; 2007: 260). In other words, if you’re impressed by the gap in math scores (I’m not), you should be awestruck at the gap in throwing ability.
I just finished writing the draft of a potential book chapter on throwing ability for a volume Prof. Robert Sands is putting together on biocultural approaches to sports. The chapter steps off from my observations that most of my colleagues in Brazil, men included, ‘threw like girls’ even though they were incredibly talented athletes, some of the most astounding capoeira practitioners I have ever seen. The book chapter is linked to some other work I’ve been doing, so I’ve got notes enough for several chapters – I thought I might put some up on Neuroanthropology.net because they were especially related to some of the things we focus on here.
This is probably going to wind up being at least two or three posts, so in this one, I’m only going to discuss the neurological issues surrounding throwing and the likely mechanical or technical issues that make (some) women (and Brazilian men and others) ‘throw like girls.’ At least one more post is going to deal with physiological plasticity beyond the nervous system, such as the way throwing remodels the shoulder, to explore anatomical plasticity more broadly, but you’re going to have to come back later for that one…