Not to confuse the issue further, but I’m kind of in the opposite camp here with sex/gender making sense separately. I spent most of my life thinking of sex/gender as synonyms.
At some point well into adulthood I became aware of a distinction:
sex — referring to physical anatomy (male or female)
gender presentation — referring to behavior — i.e., how one chooses to dress and present themselves (masculine or feminine)
Until the Leela Alcorn thread, I had never heard of this concept of “gender” all by itself as an entirely separate, undefinable, internal “essence”. And this is where it loses me, because this is where, to my view, it becomes indistinguishable from a soul, and the whole thing leaves the realm of science and enters the realm of a deeply held subjective belief.
Like most of the participants here, I’m willing to oblige that belief in the majority of circumstances. But I’m not okay with being legally compelled to oblige someone else’s internal belief, especially since I do think this concept is causing harm to other groups (as justification for puberty blockers/hormones/surgery to children and young teens, for example) and also because I am presently convinced that it is woo. No one should be legally forced to agree (or pretend to agree) that woo is true and correct.
Oh yeah, for sure. For most of my life, "gender" was just the term people used when they didn't want to say the sex-word, but the meaning was identical.
Then, way back in 2011, I took a sociology class which focused on a lot of gender themes. I already knew what trans-people were at that time, obviously, but my understanding was limited. I thought they all wanted surgery, for example, and I definitely didn't really know how all the underlying philosophy worked.
So anyway, I was taught that the trans issue is best understood if one separates the concepts of sex and gender, and views them as two different things that are intertwined for the majority of people (but not for trans people). I don't remember if non-binary or any of that side of things was mentioned at this time. I don't think it was.
The sex-gender differentiation more or less made sense to me, because my mind is capable of tolerating abstractions. But it isn't capable of processing what it sees as illogical contradictions. Separating gender and sex worked with an internal logic, but fusing them back together does not (with regard to trans issues, I mean). Now I have no idea how to understand any of it.
All that being said, as I noted earlier, it's ultimately not that important for me to understand. It's frustrating to see how polarized and odd this discussion gets, but it isn't something in which I want to get deeply involved. It's not worth it - I see points worth arguing about, but the price of doing so is looking like a bigot and alienating people. That's not worth it to me.
ETA - Also, you're right that the gender concept is quite abstract, but when I learned about it, I didn't quite see the need to invoke souls either. I merely viewed the genders as socially created categories that seem to be a part of current human society regardless of what we call them or how we conceptualize them. If a person happens to really strongly identify with one or the other, to the point that he/she wants to live as the sex most commonly connected to that gender, then that person is trans. We really didn't get into the legal side of things much back then. It was more about tolerance and gaining understanding.