I can see why they say that, it's just not right. Take, for example, what Judith Butler says in an interview with the guardian: "Perhaps we should think of gender as something that is imposed at birth, through sex assignment and all the cultural assumptions that usually go along with that. Yet gender is also what is made along the way – we can take over the power of assignment, make it into self-assignment, which can include sex reassignment at a legal and medical level."

There is no presumption here that the body is merely a blank surface for signification to come onto after the fact. I insist on the fact that Butler ties their theory of performativity precisely to already-established conventions, but says that these conventions are not fully constraining. I mean, in a certain sense that even seems to be a truism. Cultural conventions have an impact but are not immutable.

But why? We don't even have a unified global idea of masculinity today, nevermind the span of history.

Why is it that middle eastern cultures see men holding hands to demonstrate platonic affection, whereas the same act would be distinctly unmasculine in most western cultures?

Why do most modern western cultures view weeping as distinctly unmasculine, but in ancient Greece it was considered unmasculine to not weep when faced with sorrow?

If different cultures, across different time periods, can see masculinity recognized and performed in different ways, then is it not clear that there is a separation between sex and gender?