the poor and less educated tend to have more children than the other guys. [...] From what I know of population trends in recorded history, this has always been the case.
I can’t find the quote now, but I distinctly remember reading that before recent times (20th century or so), the number of children surviving to reproductive age and lifetime expected reproductive value were much higher among the wealthy elite than the vast majority of the population. It was said there that wealthy women hired poor nursemaids to suckle their babies, enabling them to give birth every 12-18 months instead of every few years (after weaning) like the poor women did. And of course infant and general mortality was much higher among the poor, especially during epidemics.
Looking at it another way, world population multiplied during the last hundred years because average global wealth rose drastically. Poor means malthusian constraints on population size, so even if you have high birthrate, in the end most of them die without reproducing because the population growth rate is vastly below the birth rate.
I can’t find the quote now, but I distinctly remember reading that before recent times (20th century or so), the number of children surviving to reproductive age and lifetime expected reproductive value were much higher among the wealthy elite than the vast majority of the population. It was said there that wealthy women hired poor nursemaids to suckle their babies, enabling them to give birth every 12-18 months instead of every few years (after weaning) like the poor women did. And of course infant and general mortality was much higher among the poor, especially during epidemics.
Looking at it another way, world population multiplied during the last hundred years because average global wealth rose drastically. Poor means malthusian constraints on population size, so even if you have high birthrate, in the end most of them die without reproducing because the population growth rate is vastly below the birth rate.