>have found that there are genetic underpinnings to the connection between intelligence and lifespan. ... When researchers controlled for smoking, for example,

>have found that there are genetic underpinnings to the connection between intelligence and lifespan. ... When researchers controlled for smoking, for example, they found that the associations between IQ and deaths related to smoking persisted, suggesting that something innate was also influencing longevity. Genetic factors that affect intelligence may affect the whole nervous system. We already know that IQ is correlates strongly with reaction speed. It would not be surprising if there is correlation with immune system (immune and nervous systems communicate) for example. pre- and postnatal health is big factor in decreasing intelligence. Parasite load and intelligence correlate in country by country comparisons.