"Where there are plenty of studies that show sex hormones affect the brain, and that there are some group-level differences between male and female brains—for example, on average, women have more gray matter then men—what’s not proven, according to Joel, “is that these effects add up to create two types of brains: male and female.”"
I suppose we can keep this up and dance around definitions forever. What's there to prove? You either can make a statistically significant guess that a brain belongs to a man or a woman based on a scan or you can't. I'm not qualified to have an opinion on the matter but honestly, I think people pushing this are doing more harm than good regardless of their intentions.
This isn't necessarily surprising. We share all the same DNA after all. A gene that makes a male a better hunter would also get passed on to his female children. Even if they don't benefit from it, as long as it doesn't hurt them, there's no selection pressure to make that trait vary by gender.
But even if the differences between men and women are only in a few small areas, that doesn't mean they don't matter.
One of my favorite studies is a school that made every students grades public like a leaderboard. They made getting good grades a competition. And the male students improved a bunch, and the females didn't change.
There are some other studies where researchers try to remove as much cultural influence as possible and give kids a selection of toys. And they find boys still prefer to play with trucks and girls dolls.
Some people try to explain away all sex differences as cultural. The problem with this hypothesis is its not falsifiable. We can't raise people in artificial cultures and see what happens. Whenever a specific cultural hypothesis is disproven (e.g. proving the tech industry isn't sexist by comparing the percentage of female tech workers to CS majors) they can just insert another one that's even harder to disprove (eg that its role models.)
I don't know what theory is true. In my personal experience, the women I have known did have very different interests and ways of thinking about things. I find it hard to believe its entirely cultural. That doesn't make them inferior or anything, just (statistically) different in a few areas.
I suppose we can keep this up and dance around definitions forever. What's there to prove? You either can make a statistically significant guess that a brain belongs to a man or a woman based on a scan or you can't. I'm not qualified to have an opinion on the matter but honestly, I think people pushing this are doing more harm than good regardless of their intentions.