There is one reason and one reason only why radical feminists have insisted that gender is a social construct. It was to deny that there are significant differences between the sexes that influence human behavior and leave their inevitable footprint on human social organization. Whatever differences exist have little to no significance beyond reproduction. This is a profoundly unscientific conception of our species. The logical consequences of allowing the "social construct" position to become intellectually legitimate are there for us all to see. We can be whoever we want to be and any society that denies you that right is...well pick your pejorative.