As far as age is concerned, just doing a Google search shows there's a ton of data both in support and against having kids at various ages. There is no single d

As far as age is concerned, just doing a Google search shows there's a ton of data both in support and against having kids at various ages. There is no single dimension called "success", there are all kinds of health, economic, and educational considerations and they're all impacted in different ways by age. Furthermore it also looks like where the study was conducted plays a big role, which leads me to think this is more of a correlation than a causation. Studies in Europe seem to focus a lot more on health in which case being younger seems to be the best time to have kids. Studies in the U.S. seem to focus a lot more on crime and educational attainment, in which case being older seems to be the best time to have kids.