aside from being cissexist the whole XX = female and XY = male thing is Straight-Up Wrong
AFAB people can have XO, XXX, XXXX and XY chromosomes while AMAB people have have XXYY, XYY, and XX chromosomes and since the majority of the population never has their karyotype examined, they’ll never know that they have one of these chromosomal quirks unless that specific combination has associated symptoms, and not all of them do. you could literally have one of the aforementioned combinations without even knowing it and meanwhile you’re insisting that all AFAB people are XX and that anyone else who has this must also be female
we could also talk about how hormonal patterns for XX persons can naturally and biologically mirror that of a typical XY person, or vis versa, which gives rise to things like androgen insensitivity disorder. here u have it, folks, an whole group of intersex people who have XY chromosomes and testicles and vulva and vagina, all grown naturally, all at the same time.
the number of people who are intersex mirror the number of people who are born with red hair, but no one goes around trying to say that red isn’t a natural hair colour just because the phenotype doesn’t manifest in the majority of the population.
seriously consider the bold if you are aggressively upholding the ridiculously flawed theory that is the sex and gender binary.
Big genetics nerd here, with a biology degree for whatever that’s worth. I’ve been saying this for well over a decade (i.e. it’s not a “tumblr thing” lol). The whole “XX = woman, woman = XX” thing, ditto for XY and men, works okay as a rough guideline but it’s simply not a universal “rule”. So telling trans people “you’ll always ‘really’ be [assigned gender], because chromosomes” is scientifically ignorant nonsense for three reasons:
- Sex differentiation in humans isn’t really controlled by chromosomes. In species where it is, things like bilateral gynandromorphism can occur. That’s not possible in humans, though, because our development is controlled by hormones. Our chromosomes play only a very small role.
- Because people don’t know other people’s karyotypes (or even their own, most of the time), they’re just pre-selecting the conclusion they want, then “proving” it with “evidence” they don’t actually have.
- Because other conditions can also produce XX men and XY women, the idea that a trans person’s karyotype determines what they “really” are is a blatant double-standard. One which exists solely to “prove” the pre-determined conclusion that cis people’s genders are valid, and trans peoples’ aren’t.
Consequently, there are only two scientifically informed, logically consistent options:
- Accept that nature is more complex than one learned in 5th-grade science class, and chromosomes can’t tell someone’s “real” gender. DNA is a truly wondrous molecule, not some Magical Essence of Gender.
- OR, double down and demand to see everyone’s karyotype. Refuse to respect anyone’s gender if the results aren’t what one expected. Insist that all cis people with “mismatched” karyotypes must transition against their will, and be transphobic toward them until they do.
In other words, transphobes claim to be authorities on X and Y chromosomes, yet have no clue what they’re talking about.
Cisnormative society has a bizarre obsession with finding the One True Indicator of Biological Sex. Chromosomes are just the latest answer. In the past it’s been ovarian/testicular tissue, or penis/clitoris size. What will it be fifty years from now? But whichever One True Indicator is the current fad, there’s always at least one intersex condition which contradicts it, thus exposing how ridiculous and arbitrary these indicators really are.
Not that transphobes let facts stop them, of course. If someone doesn’t fit either One True Sex, they just don’t count! (I’ve literally heard this.) Cis people with reproductive, endocrine, or urogenital disorders still “count,” of course. An XY man with a small, hypospadic penis? An XX woman born without a uterus? Eh, just a man and a woman with minor quirks. A non-XX woman or non-XY man? They ~don’t count~, because ~disorder~. What an odd coincidence that this magical gender-invalidating power of “disorder” only applies to people who threaten the all-important binary. Circular logic at its finest: the binary is real because anyone who disproves it doesn’t count, and they don’t count because if they did, they’d disprove the binary!
That isn’t science. It’s not nature, or reason. It’s bigotry, plain and simple.