> Obviously there are examples of cultures where men cook or women hunt, but I can't find any culture around the world where women don't traditionally have nurt

> Obviously there are examples of cultures where men cook or women hunt, but I can't find any culture around the world where women don't traditionally have nurturing roles. How much of this, do you figure, is survivor bias? If there were just a few dominant cultures historically who happened to have a patriarchal bias and which went on to be profoundly influential over a large volume of the planet (like, say, the Romans, the Chinese, etc), it stands to reason that male-female relationships in the many, many cultures that were shaped by them would simply happen to exhibit these traits, not because of biological constraints, but because of simple historical happenstance. Cultures which failed to fit this mold would be "civilized" when they came into contact with the dominant cultural hegemony, and relatively few counter-examples would survive. Thus we can find in small, isolated pockets surviving cultures like the Aka, who split "nuturing roles" equally and fail to fit your hypothesis, but outside of extremely isolated cases it is hard to find cultures that run counter to what you perceive as biological norms precisely because it is hard to find any culture that wasn't extensively re-shaped by contact with one of a handful of historically dominant civilizations