Not sure if you’re joking or being sarcastic, but here are a few examples where the mere absence / presence of a Y can’t determine sex & gender.
Sometimes a person has XY chromosomes, but the body developed in a female manner because the fetal cells were resistant to testosterone. Such a person has good claim to being a woman (she developed that way) or a man (he has a Y chromosome; his brain could have been sensitive still to the testosterone to still develop male-coded)
Sometimes a person has XX chromosomes, but the body developed in a male manner. Usually (though not always) this is caused by part of a Y chromosome ending up on an X. Such a person has good claim to being a man (he developed that way) or a woman (maybe she lacked enough testosterone to male-encode the brain).
Other conditions such as XXY combinations, or chimeras (some cells XX, some cells XY), or other intersex conditions where some body parts develop male, some female.
To me personally, I view trans people as a type of intersex person. It seems entirely possible that you might have a person whose brain cells were more or less resistant to testosterone and/or exposed to testosterone and truly is a man/woman in a woman’s/man’s body. You don’t need to bring choice or culture into it - I think biology alone provides good evidence to believe trans people about what gender they claim to be.
Not sure if you’re joking or being sarcastic, but here are a few examples where the mere absence / presence of a Y can’t determine sex & gender.
To me personally, I view trans people as a type of intersex person. It seems entirely possible that you might have a person whose brain cells were more or less resistant to testosterone and/or exposed to testosterone and truly is a man/woman in a woman’s/man’s body. You don’t need to bring choice or culture into it - I think biology alone provides good evidence to believe trans people about what gender they claim to be.