Even exterior anatomy can be indeterminate, as the intersexed remind us. What we do know is that every culture has created a system of gender to manage breeding and family. Bi-Polar ones are called heterosexist , encouraging coupling over community and having a focus on breeding, and in our case, consuming. Males don't hunt. Men hunt, and today they don't even do much of that.
Sex is between the legs, gender between the ears.
Sex is what we are given, gender the societies we construct around it. Women are made and not born.