There is tons of research on this. Higher IQ at young ages, independent of social class, strongly predicts health outcomes. Since it also predicts income, and

There is tons of research on this. Higher IQ at young ages, independent of social class, strongly predicts health outcomes. Since it also predicts income, and since a big part of IQ can be predicted before birth, IQ seems to be the real driver here. From here: https://en.wikipedia.org/wiki/Cognitive_epidemiology https://en.wikipedia.org/wiki/Cognitive_epidemiology A strong inverse correlation between early life intelligence and mortality has been shown across different populations, in different countries, and in different epochs."[3][4][5] A study of one million Swedish men found showed "a strong link between cognitive ability and the risk of death."[6][7][8][9] A similar study of 4,289 former US soldiers showed a similar relationship between IQ and mortality.[7][8][10] The strong correlation between intelligence and mortality has raised questions as to how better public education could delay mortality.[11] There is a known inverse correlation between socioeconomic position and health. A 2006 study found that controlling for IQ caused a marked reduction in this association.[12] Research in Scotland has shown that a 15-point lower IQ meant people had a fifth less chance of seeing their 76th birthday, while those with a 30-point disadvantage were 37% less likely than those with a higher IQ to live that long.[13]