Although gender is not a binary concept. I honestly do think that gender is mostly a social construct but our definition of what it is is much better than it used to be - sterile men and barren women would often be considered outside of standard gender definitions since they couldn't "fulfill the intended role".

I have problems on this front though, I'm pan myself and gender seems really insanely trivial to me - I do understand that my experience is not the common one though.