Quite apart from all the evidence pointing towards a biological basis for gender identity, ultimately I think the most important thing is to have basic respect, decency and compassion. When someone tells me that her core identity is female, I really have no reason at all to believe otherwise, and to intentionally refer to her using the wrong pronouns, or say that she's a man pretending to be a woman as part of some sexual fetish, would be incredibly dismissive and insulting.
My point was that there are differences between male + female brains. Some even occur during the development of the fetus. Which means saying that there are either no differences at all between male + female brains or saying that all differences are caused by "society" is simply silly and factually wrong.
You may call conclusions of researchers silly or ridiculous, but this doesn't make the physical differences go away.
Sure, but the conclusions of researchers may not always take into account social conditioning and neurological plasticity (or in some cases are methodologically flawed). The thread Mumei just linked to goes into more detail about the ways in which brain differences do not always correlate to behavioural differences. The idea that there is a four year gap between the "mental ages" of boys and girls when it comes to maths hasn't been rigorously confirmed, and stands at odds with numerous other studies, including this
worldwide study which not only found very few gender differences in maths ability but also showed that when differences do occur they tend to correlate with disparities in opportunity and education between the sexes, which is hardly surprising. I don't really dispute that there are, on average, differences observed between male and female brains; that's pretty clear. But I'm very,
very iffy about the claims that these are indicative of hard-wired sex-based differences in ability in maths, music, art, language, etc. That's the point I was really disputing (which is starting to go off topic from the subject of this thread).
That makes sense. But I would go further and ask why is that so. I mean: what exactly is different?
To be honest, I don't know what in particular will lead to someone's unique gender identity, and I don't believe anyone does with 100% certainty at this stage. My guess is that the biological side of things doesn't come down to any one single factor, but would be the result of a rather more complex interplay between hormones and brain development. There was a study in 2008 by Swaab and Garcia-Falgueras that claimed to find a relationship between gender identity and the anterior hypothalamus, but this isn't the sole focus of research:
http://www.ncbi.nlm.nih.gov/pubmed/18980961