I fully support the need for a female category to encourage women and girls to compete.
In the meantime, this has been an interesting discussion to follow on Twitter.
Carole Hoovlet on Twitter. 20.51 17/8/23
I'm quote-tweeting this because my initial response generated a lot of discussion and I want to get it right. (FYI my dissertation was on sex differences in spatial ability, so I'm sure that's biased my view of this issue.)
It's funny that I asked for help from Chris Chabris @cfchabris on this sex differences in chess question, because he's a highly ranked chess player and an expert in intelligence. And he thanked me for "helpful conversations" in his 2006 paper on this very topic (below). Which I admit to forgetting about (the paper, and the fact that I helped him with it in some way).
Chris and Mark Glickman found that the larger pool of male chess players appears to contribute to, or even explain the male advantage (someone on here suggested this). But why are males more interested in chess in the first place? Many non-spatial factors contribute to chess success, including other aspects of cognition, but also interest in the activity, desire to stick with it (over the course of a single game or longer), drive to win, etc, and a sex difference in any of these areas could play a role in the male advantage. We don't have great research on the various contributions, or their origins. So in my original tweet, I may have overstated the importance of spatial ability to the male advantage (as I commented right after I posted that tweet!).
The important thing is that if a girl (or woman) is motivated to learn and excel at chess, she will improve with practice and if she loves it, she should play her heart out! She might even beat many men or even become a chess master.
But in any event: even if biology is not found to be a strong contributor to the sex difference, particularly given we don't know the cause of the male advantage, the fact that it exists is reason enough to keep the female category for females, which is the best way to give females a chance to win.
journals.sagepub.com/doi/abs/10.1111/j.1467-9280.2006.01828.x?casa_token=fFrGmtb8zqEAAAAA%3A0fTQs-UkjhKnTO2yaiJUhmy9yNQrXLPr1kEsInDbNuzvP0jm0CTTM71EFzSyZXvprf19L9V-cpbv&journalCode=pssa
twitter.com/hoovlet/status/1692262830219596050?s=12
It isn’t quite as cut and dried that there is no testosterone advantage. The research is ongoing.