Look a guy named 'John money'....unironicsally his name...was the first to use the word gender as somehow tied to biological sex. In the 1970s.
It was pretty stupid. Carl Jung had already approached many of these subjects...and named animus as the repressed masculine drive of a woman, and Anima as the repressed feminine drive of a man. And actually was quote similar to the esoteric fascist philosopher Julius evola on these topics.
Now what the word gender has BECOME is a weird spiritual category which is first and foremost UNMEASURABLE.
Meaning it has no scientific merit. It is religion...theology.
And here's a funny punchline. The guy who started using the term 'gender' (previously restricted to linguistics)...tried to use it to promote some philosophy of 'testosterone supremacy.'. No joke. He suggested a woman with more testosterone than a man was superior to that man.
**** crazy ehat you discover when you dig into the history of this ****.