Just a quick note about brain and cognitive ability differences and sex--the differences that are discussed between males and females are extremely small statistically speaking. The overlap in ability is massive compared to the observed average differences. If you compare the size of these differences with something like average height differences between males and females, which is a strong difference, it really looks minor. Additionally, there is good data that suggests that socialization has a very important influence on these abilities; while most people don't realize it male and female infants are treated differently from day 1 (though I suspect we trans people are more aware of gendered socialization due to how our assigned gender didn't mesh with us). Boys are encouraged more to participate in activities like building blocks and throwing balls, both of which increase spatial ability (boys are on average initially slightly more interested in these activities, likely due to some "hardwired" differences). The same is true for girls and social play. The belief that boys' weaknesses in verbal ability and girls' weaknesses in spatial computation are innate/hardwired mean that educators work less on building these skills in kids ("Oh, he's a boy, he's naturally bad at reading."), which reinforces these skill gaps over the years. And if you bring stereotype threat in, well, that makes it even worse. Stereotype threat is the well-studied phenomenon in which reminding someone that their social group (e.g. gender) has a particular negative stereotype means that they do worse on tests measuring ability in that area. Like reminding girls that "girls are bad at math" makes them score worse on a math test than when this isn't brought up.
A really good book on cognitive differences in gender (where all this info came from) is
Pink Brain, Blue Brain by Dr. Lise Eliot. It's got a lot of data, but I still think it's accessible and a really interesting read.
That's not to say that I don't think these effects are real--these hormonal effects are particularly convincing because you have a "true experiment" rather than just correlational data. One thing I wonder about, that doesn't seem to be addressed here, is a potential difference here between cis females and FTMs when testosterone is given. If FTMs have brains with structures that mean they "should" have higher T levels (so, a "male brain"), you could see greater improvement in spatial skills in FTMs than cis females with the application of T. I'll have to do a lit search and see if anyone's looked into that.
Quote from: Mr.X on March 25, 2013, 02:53:06 PM
But that raises another question. What about MtF's? Do they also get two sides of a coin, or are they actually losing this spatial ability and gain verbal fluency?
I looked up the paper, and oddly enough, they got no differences. MtFs neither had a decline in spatial ability nor an increase in verbal ability.
