AFAIK intelligence (i.e., IQ) is correlated with lifetime financial success - or at least is indicated as such in psychological literature, and to me seems sens

AFAIK intelligence (i.e., IQ) is correlated with lifetime financial success - or at least is indicated as such in psychological literature, and to me seems sensible intuitively. So, it is believable that the children of the affluent (and probably intelligent) tend also to be intelligent, in addition to receiving better education capitalizing on this. Both (or perhaps really two sides of the same coin) may play a role.