factor contributes to the widening income gap? I had lunch with a group of friends yesterday and one couple has a daughter who is pursuing a joint MD/PhD at Stanford after getting her undergrad at MIT. Their daughter has a serious boyfriend and they think they will soon get engaged. The boyfriend is also MIT undergrad and is getting his PhD in quantum physics at Stanford. I'm guessing if they get married and have kids, their kids will likely be very, very smart. That's obviously an extreme example, but generally speaking I don't think smart people are attracted to dumb people and vice versa. Given that 50-60% intelligence is inherited, do you have smart people marrying and producing smart children and dumb people marrying and producing dumb children and that further perpetuates the income gap. There's some regression to the mean on intelligence (smart couples can't keep having kids even smarter than them indefinitely, and god forbid, dumb couples can't keep having even dumber kids generation after generation.... although that could explain today's GOP) but in today's knowledge economy, intelligence plays such a large role in one's ability to be successful and earn a high income. Could this also play a factor in the income or success gap (in addition to the obvious non hereditary advantages that kids of smart, successful people have).