Studies have shown the relationship between intelligence and mortality. I was excited to read an article in Nature about why do intelligent people live longer? People's rankings on intelligence tests show high stability across almost the whole lifespan, are substantially heritable and are associated with important life outcomes — including educational achievements, occupational success and morbidity and mortality.
The article talks four explanations about this.
First: intelligence is associated with more education, and thereafter with more professional occupations that might place the person in healthier environments.
Second: people with higher intelligence might engage in more healthy behaviors. Evidence is accruing that people with higher intelligence in early life are more likely to have better diets, take more exercise, avoid accidents, give up smoking, engage in less binge drinking and put on less weight in adulthood.
Third: mental test scores from early life might act as a record of insults to the brain that have occurred before that date.
Fourth: mental test scores obtained in youth might be an indicator of a well-put-together system. It is hypothesized that a well-wired body is more able to respond effectively to environmental insults.
But above evidences don't necessarily explain the intelligence and mortality to all people. There are many others factors to be explained, in my opinion.
To read full article in nature please click on the link.