Suggesting the Correlation Between Intelligence and Longevity is Mostly Genetic
Researchers building on twin study data are suggesting that the well-known correlation between greater intelligence and a little additional longevity is mostly genetic in nature, not a matter of more intelligent people making better lifestyle choices, or tending to be wealthier, or any of the other social or economic factors that are associated with both intelligence and longevity. The size of the effect due to intelligence is small, but a demonstration of it being due to genetics is not the result I would have expected based on past data on human longevity. To date I'm aware of little other research to back this point of view. For one of them, you might look at a paper from a few years back that suggests learning and longevity in bees are both influenced by the same underlying mechanisms of robustness in biological systems, their resistance to stress.
The tendency of more intelligent people to live longer has been shown, for the first time, to be mainly down to their genes. By analysing data from twins, researchers found that 95 per cent of the link between intelligence and lifespan is genetic. They found that, within twin pairs, the brighter twin tends to live longer than the less bright twin and this was much more pronounced in fraternal (non identical) twins than in identical twins. Studies that compare genetically identical twins with fraternal twins - who only share half of their twin's DNA - help distinguish the effects of genes from the effects of shared environmental factors such as housing, schooling and childhood nutrition.
"We know that children who score higher in IQ-type tests are prone to living longer. Also, people at the top of an employment hierarchy, such as senior civil servants, tend to be long-lived. But, in both cases, we have not understood why. Our research shows that the link between intelligence and longer life is mostly genetic. So, to the extent that being smarter plays a role in doing a top job, the association between top jobs and longer lifespans is more a result of genes than having a big desk. However, it's important to emphasise that the association between intelligence and lifespan is small. So you can't, for example, deduce your child's likely lifespan from how he or she does in their exams this summer. It could be that people whose genes make them brighter also have genes for a healthy body. Or intelligence and lifespan may both be sensitive to overall mutations, with people with fewer genetic mutations being more intelligent and living longer. We need to continue to test these ideas to understand what processes are in play."