As I understand it, on average, it takes three children to produce a rational woman. In other words, the female mind evolved to carry a certain cognitive load, (just as did the male) and without that cognitive load doesn’t perform well.

Women with children are less crazy than those without. Women with three or more are less crazy than those with fewer. Women with four to six children do not have the luxury of insanity.

So it is better to think of it as men need a physical load and an a loyalty load to stay fit, and women need a cognitive load to stay fit. And for women that fitness comes from governing a brood of children.

Evolution is almost always understandable.