Not sure what you mean by scientific versus sociological. Science has found that there is a lot between XY and XX, not sociology. There are all kinds of genetical and biological conditions between unambiguous male vs female. Mosaicism, Turner, Klinefelter, androgen receptor deficiency etc.
And there is neuroscience, also a science, not sociology, that says the brain is the most important sex organ, and it can be biologically marked in opposition to the physical body in some cases.
Sociology is also an aspect, but personally I‘m more interested in the scientific perspective.
Anyway, an open mind is a good thing. 👍