I have a good-faith question, and I hope you won't think it's transphobic to ask.
If gender identity is coded in your brain and has absolutely nothing to do with society - how does that work?
In my experience, which obviously is no one's experience but my own, gender is a qualia. Which means that I have no idea whether my "gender" is "really" that of a woman. All I know is what it's like to be me, existing in this body, which people around me tell me is female, and which I can see by comparison to other people, is similar in most ways to other people also called female, and different in many ways to other people called male. But is this feeling of "me-ness" really gender? I look inside myself for a unique qualia for gender that I can isolate from the other qualia of being an individual consciousness in an individual body, and I can't find it! All I can get is this nebulous "being OK with having female secondary sex characteristics, and being ok with being seen as female and presenting as female in my society's expectations of what female means". That's not "gender" though, is it? Cause it's not hardwired.
And when I was a child, I grew up with brothers and for several years thought I was just arbitrarily called "girl" and they were called "boys" but didn't know what that really meant until I had a bath with them one day and saw we had different parts. I presented very masculine until the age of 11 - short hair, masculine clothes, "masculine" activities - I was allowed to do that, but I also enjoyed playing with "girl toys" too as did my brothers. So where was my innate gender? I didn't feel it, or at least I couldn't divorce it from the fundamental experience that is "being myself". I had and have, no one to compare "the intrinsic feeling of being a woman" with - for all I know it feels very different to every other woman on the planet, because it's a qualia. It can never be directly compared, just like I can never know for sure that what I call "red" is the same experience of a colour as someone else's "red". Do you know what I mean?
Now gender dysphoria I understand, because it is a deep dissatisfaction between your body, your internal sense of self, and how you're perceived by society. I'm not invalidating it, or invalidating transition as a way of overcoming that.
But I genuinely don't understand the "gender is in the brain from birth and is completely separate from secondary sex characteristics or society" argument. Because how do you know that what you consider gender, is in fact, gender? How do you know whether your sensation of what you call "being a woman" is in any way similar to what other people say their feeling of womanhood is?
This argument btw isn't to say you shouldn't call your qualia "womanhood". We all have just as much right to label our subjective experience as anyone, and so no one can tell you that you DON'T experience the qualia of gender the "right" way and thus should be gatekept from "women's spaces".
At the same time, qualia is a deeply personal experience. I can't say that I am a "real woman", with any conviction, if we go by gender identity. I can just say that I am (my name) and that I'm relatively comfortable being seen as female, and having female secondary sex characteristics. But I have no idea whether my internal sense of self, to which I attach the label "woman" simply out of comparison to others who also call themselves that - is "really a woman".
So I find it a bit odd to insist that ANYBODY be affirmed as "a real woman" as no one can know what your qualia is, all outsiders can ever know is your sex, which is complex and multifaceted, only you can ever know what it's like to be "you". So they can't tell you what you feel is wrong, but I also don't see how anyone can claim that their own qualia is "the right one" (ie the same as a cis person's qualia) either. As in, quibbling about whether or not "a trans woman can ever REALLY be a woman" and people come down hard on either side of the argument when I find it to be kind of unnecessary. For all aspects related to qualia, go with what the individual says their experience is (so if you say you're a woman, you're a woman, I can't say otherwise, and so I'll treat you as a woman), but it doesn't make sense to me to conflate qualia with biology or try and claim that a qualia is "hardwired" and can thus be "proven scientifically". It can't. It's why there's no "gay gene" and no part of the brain that makes you gay. It's not a choice to be trans, and it's not a choice to be gay, but that's not the same as saying that the qualia is "hardwired from birth". It shouldn't have to be in order to be valid. People should just let people live and not be assholes.
Does that make sense? I'm truly asking in good faith. I would like to understand your perspective and how you differentiate "gender" from the other subjective experiences that make you, yourself.