I would say at least in cursory observations of people that is true, but then I also think there is environmental considerations. Broken people tend to hang out together creating a greater case for it. Well-adjusted people tend to hang out with like people. I'm sure that if I were a totally well-adjusted person and hung out with less damaged souls then I would have an idea of it being far lower or very exceptional. Whereas, because I tend to hang out with people that have similar backgrounds to my own it seems higher. Its the fish tank effect.