I'm talking about the very basic level, where women generally have nurturing roles: raising children, caring for the sick and dying, preparing food/clothing.
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.
> 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
The Aka represent sex roles that have underlying characteristics familiar to all cultures. Some culture in the world must have the most objectively nurturing fathers, and the Aka happen to be it. But, it's the poorer in their society that are nurturing. High status Aka men who have enough resources accumulate multiple wives and offload nurturing onto them. This wouldn't raise the eyebrows of any student who's studied the history of human cultures around the globe. Instead, it'd be shocking if it turned out that high status women married multiple husbands to take care of the nurturing.
I'll recount from a 10+ years gap of memory - and also with a disclaimer that this is not my area of expertise, by far. So, please don't believe me without additional supporting evidence.
However, what I took away from those classes was that gender was a very mutable 'invention' that Humans created through culture to systematically specialize labor in response to environmental forces. Some cultures invented two-genders, aligned with biology, to succeeded in environments where two specialized gender roles were more advantageous. However, other cultures of Humans invented several types of genders, and genders that crossed biology, to succeeded in different environments.
So, if those memories are even accurate, gender and gender roles in Humans are more aligned with the overarching systematic cultural forces than biology. And, even if we consider biology, there is a lot of cross-over. Humans are a very adaptive and mutable species.
You seem pretty confident in your claim. But, yet it goes against most of what that my freshman and sophomore anthropology professors taught me.