Thought this was an interesting article and wanted to comment on it, but wasn't sure where it should go. Higher salary may be predicted by this behavior in kindergarten, study finds https://www.foxbusiness.com/personal-finance/higher-salary-predicted-behavior-kindergarten Both inattentiveness and physical aggression in boys can be linked to testosterone levels. Testosterone is also negatively correlated with IQ... boys with higher IQ's have lower testosterone levels and vice versa. It says the study controlled for IQ, but that may have just lumped all the physically aggressive boys into one group at the bottom of the IQ scale. It would be interesting to know how they measured kindergarteners' IQ, too, since childhood IQ and adult IQ is not a 1:1 correspondence. One study has linked exposure to lead to physical aggression in boys and men, and another study linked a vitamin deficiency to physical aggressiveness in teen boys (niacin, I think). Neither of these factors was mentioned in the report.