In general, those who can send better signals should put more effort into signaling. In particular, those with a better shot at them should work harder to gain status markers. So women with better relative endowments should delay and reduce kid raising efforts; their fewer high status kids would make for more great-grand kids. And since farmer status inequalities were bigger than forager inequities, this effect was stronger for farmers.

Monday I described Bill & my suggestion that this effect might explain the demographic transition, if our subconscious minds neglect the possibility that whole societies could get and long stay rich. That is, we see that by ancient standards we live like kings, we might be fooled into thinking we have a chance at king-like status and relative reproduction success, if only we work extra hard to achieve status markers. But in fact, we can’t all reproduce like kings.

Tuesday Bryan objected:

Unless I’m deeply misunderstanding it, this “excellent” theory doesn’t even get off the ground. Like Feyrer and Sacerdote’s theory, Dickens-Hanson implies gender conflict: In the modern world, men should want more children than women, and this gap should get larger as people get richer. But in reality, men and women around the world see eye-to-eye on this question – see the World Values Survey, question D017. But doesn’t the Dickens-Hanson mechanisms work for men, too? Robin thinks it does, but admits that it doesn’t work as strongly:

I just don’t see that our theory implies gender conflict on family size. By “[the theory] doesn’t work as strongly [for men]”, I meant and said:

So men should work even harder to gain status markers. But even so, raising overt kids will less distract men from pursuing high status, and a man’s delay in starting kids will less reduce his fertility. Thus excess male status efforts probably do less to reduce overall fertility.

Since men are even more eager than women to gain status, and stay fertile longer, if men shared kid raising efforts equally they might well want to delay kids even longer than women want. But if women bear most of the kid-raising burden, that should make men more eager to have kids earlier. The net effect of these factors isn’t clear.  So I see no clear net prediction of our theory about how people should answer a survey question about “optimal family size.” (And I’m inclined to pay more attention to how many kids people actually have, relative to survey responses.)