Bostonian, did you read the full study? Your objections don't make very much sense in light of their methods. Their point wasn't, "Girls are bad at chess; it must be because of stereotype threat." Their point was, "Girls at certain ages and in certain situations lose to boys at higher than expected rates, statistically--perhaps due to stereotype threat." As I noted earlier, the oldest girls appeared to be somewhat immune to ST, which is interesting. The girls who were most susceptible were younger and were playing older, more highly rated boys (a situation that could be especially intimidating).
Also, if girls are naturally worse at chess and that's why they don't play as much or win as much, I wonder how you explain the fact that there are many more girls playing chess in the younger grades than later on? Do girls get more and more "chess stupid" as they age?
What about your daughter, who plays chess, correct? (And is pretty good at it, IIRC.) It would be hard to know that your dad expects less of you due to your chromosomes.
