"There are things so fundamental to being male or female that none of us have managed to describe what it is."
For so much of human history it was assumed that men and women were fundamentally different in the head. Given the social construction of gender (or at least gender roles), and their variability across cultures and across time, and given societies seeming obsession with making men and women as disparate as possible in areas beyond where the actual biological differences operate, we must surely remain extremely sceptical about labelling anything as innate. Especially things we can't define..........
Given society, it is no wonder that it is a common belief that there must be something fundamental to being male or female, other than being raised in a male or female body and noticing that you pee differently. Supposedly before the social conditioning sets in. Except we also know that such conditioning sets in straight away, that people just do treat babies they perceive as male or female differently.
So, what remains as the supposed evidence for innate gender identity? Indeed, I have been told that innate gender identity must exist because trans people do. Which closely follows the "sexual orientation must be innate because gay people exist and they're not sick" line. Which is more to so with politeness than actual science! And then gets even murkier when bi-gender and gender fluidity come in as well..........
I'm a lesbian, and I reject the 'innate sexual orientation" argument because socially, my responses is, 'what is wrong with being lesbian even if I did chose it?' -- because being straight or gay or lesbian or bisexual doesn't actually require anything much more than treat all adult humans as reasonable adult humans, whoever they happen to want to have relationships with.
As regards gender identity then, perhaps rather than being an answer or explanation for the occurrence of trans people, we might ask why should we care what gender someone is (or none)? What if we got rid of gender? Okay, sex is always going to matter in some areas, like who gets pregnant, and who bleeds, and who you should compete against in cross-country races. But perhaps the issue of trans people has only arisen because society cares so much about gender? If we got rid of that, then we would perhaps be left with sex dysphoria etc, and people who just had issues with their physically sexed bodies. And then we would have to look at whether or not surgery and/or hormones were effective to help alleviate such dysphoria, or whether people should be allowed such surgery just cos they want it. But whilst also acknowledging that physical sex cannot be altered however much some people may wish it could be. Then we are left with various reasons for people wanting physical intervention, and hopefully treating those range of reasons in a range of ways. But believing in innate gender identity both causes the problem in some sense, and also prevents a flexible and effective response to those who need it. Shoving it all under the 'innate gender' umbrella doesn't help, and actually that paradigm is already creaking given the multiplicity of genders already arising. If gender is a spectrum, after all, and presumably multi-dimensional if not totally warped (in the maths sense), then how does it become innate (if so fluid), or distinguishable from 'human personality'???
And I keep coming back to the Monty Python line -- 'where's the fetus going to gestate, in a box?' and the fact that it's no ones fault, not even the romans.........................