It’s all society. Always has been. Always will be. There are some very specific biological differences in the two sexes, and we’ve used those real differences to decide a bunch of fake differences we stick to out of convention. There’s an idea of what a man is in our collective unconscious, an archetypal “man”, and that’s what people refer to, but that archetype is breaking down. Man, woman, gender in general. We’re realizing that those distinctions aren’t useful, and sometimes, maybe even most of the time, are detrimental.

That all said, humans are social creatures. That pressure, that idea of “man” is all around us. It’s absolutely understandable that people can still generalize what “man” is. The concept doesn’t have to be based on anything tangible to be relevant to our species.