>>11202976Culture is downstream from biology. So our "culturally defined gender roles" are simply expressions in culture of biologically ingrained preferences.
As for classification, that's difficult because we're looking at statistical phenomenon when it comes to whole populations.
But we all have a pretty good idea what, in general, constitutes masculinity and femininity. Here's the main thing: our concepts are based on archetypes, not on definitions. We're all going to think of more or less the same thing when we picture a male or a female archetype. The difficulty arises when you depart from this archetype and look at the edge cases. Definitions use used to describe these edge cases: you define the borders of a category that allows you to neatly place a given instance into said categories.
It may simply be that this kind of definition isn't really appropriate in the first place, much like there's no clear way to define when a fetus or embryo becomes a human being.
