Quote Originally Posted by Renton View Post
It's just people and choices. Fertility rate goes down as people get richer and it makes less and less economic sense to have children. In developing countries people have ten children just because that's the highest EV decision for them. Not a lot of 401k's in the third world so people have children as kind of a pension program. In the U.S. people peak out in earning potential in their 40s and 50s and are more likely to be investing in their children's college than the other way around (being supported by one's kids).

There's also the r/K selection theory which has some things to say about this, but that's probably a topic for another thread. Cliffs: certain types of animals (and certain people) breed for quantity over quality (r selection), as a form of brute force method of ensuring their genes are passed along, while taking many risks that result in a low survival rate. Conversely others invest in fewer, quality children while being more risk averse. Rabbits are an example of a generally r-selection species, while lions are more K-selected, but r and K behavior can coexist in the same species. There's a theory that humans, while generally K selected, have developed some r-selected niches since the industrial revolution. It gets political from there, so I'll leave that for another topic (spoiler: leftists tend to be r).
I'll just chime in real quick on this particular point because what you just said is so important: On the alpha/beta spectrum, alpha behaviors at an extreme tend to lead to r-selected situations and beta behaviors at an extreme tend to lead to K-selected situations (the extreme itself being raising someone else's primarily r-selected kid as if it was your own in a K-selected fashion).