Rob, I think your comment illustrates my point perfectly. You say that "gender is a social construct" but then in the same sentence you refer to "the female/male gender-binary" and its supposed absense in various cultures as evidence.

But female and male are biological sex categories. So are you equating gender with biological sex and claiming that both are socially constructed? Or do you see sex and gender as separate? And if they are separate, are they both social constructs, or just gender? And even if they are socially constructed, what would be your definition(s) of them as such? Or would you claim that as social constructs, the concepts are not objectively real at all, but just ideas that are open to subjective interpretation?

I cannot even begin to evaluate, let alone understand, your claim without answering all of the above questions, none of which have obvious answers based on the statement itself.

So you can hopefully see my point that gender, as it's beginning to be used, is a mess of a concept. And how can that be considered progress?