One possibility is that wealthy people with few (often just 1) child, a stable home life, fewer financial pressures, etc spend a lot more time on the child. An

One possibility is that wealthy people with few (often just 1) child, a stable home life, fewer financial pressures, etc spend a lot more time on the child. And this keeps them out of trouble more often. Also, a lot of the education around avoiding pregnancy is about the financial future of the child (eg getting present in high school will ruin your life). For that to have an impact, the child has to think they have some kind of future.