Recently I have come across the idea that the difference in women being interested in people and men being interested in things might be both the results of the personality, and not gender and it might be the result of the testosterone level in pregnancy.
So far, I have not read the article, that deals with the personality part of it, but I have read one or two that dealt with the hormone part of it. While it would apparently me unethical to test this in humans experimentally, there were still some studies done.
It helps that ethical guidelines for animal research are a bit more lax than for human research as well. Apparently, if one treats a female animal with testosterone, then it develops a more male-like behavior. I imagine that this means, that this animal gets more aggressive and competitive. I mean I am assuming this, because I imagine that at least some gender differences has to come from gender differences in agreeableness. But I might be wrong. Also, it is a stereotypical behavior for each gender, right or wrong.
Well, it was not just females that were tested, but also males. If male animals, when they were very young, got their testicles removed, then their behavior becomes a lot more female-like. So we could use this to create cooperative bulls, and attaching cows. And there would not even me a mad cow disease involved. I know, it is not rabies, so it is not likely that infected beings would suddenly start attacking anybody.
But there have been some studies also done on humans. They have shown to affect the gender-related play and gender identity. For example, an experiment compared the children with classic congenital adrenal hyperplasia to their relatives. They took both groups and tried to teach them, either by modeling or explicitly about the unrelated gender connection. For example trying to teach them that silver is a girl's color. Then they watched what toys they played with and asked them which toys did they prefer. In a group of girls, the ones with classic congenital adrenal hyperplasia, meaning ones with more testosterone exposure during pregnancy, were less likely to adhere to the gender roles than girls without thins condition.
Also, men with complete androgen insensitivity syndrome, show reduced wish to engage in male-play, and they are also much more likely to identify as females. For people familiar with House MD, this syndrome was presented in the episode Skin Deep. If you are not familiar, than I will not spoil it too much, as I was recently informed that most people hate that. But I think I can say, that it is a syndrome, where cells are 'immune' to the male sex hormones.
On the other hand, the level of male sex hormones, which can also be called androgen, can affect the gender identification in women, where women have a less strong women identity and are more likely to identify as man as well. The same is true for males. Lower levels of androgen cause more female-like identification.
I have also head that testosterone is connected with aggression between ages of 16 and 25 years old. And that the creativity curve is the same as the aggression curve. If I remember correctly, it might be only talking abut men.
Now I am a bit interested, if the testosterone also affect the personality in the specific way, shown through any of the model. But so far I have not read about this yet.