If you're gifted in the brains department, you can thank your genes -- not only for your intelligence, but also for what may be a longer life.
A team of researchers recently set out to determine whether the link between smarts and longevity is related to environment -- things like a healthy lifestyle-- or is simply due to genetics. After looking at over 1,400 pairs of twins in three long-term studies -- where both intelligence and age of death were noted -- they discovered that the tendency of smarter people to live longer is thanks mostly to their genes.
Although the correlation was small, experts at the London School of Economics and Political Science discovered that 95 percent of this connection is genetic while only 5 percent is related to the environment, according to research published in the International Journal of Epidemiology.
They found that, within twin pairs, the more intelligent twin usually lived longer than the less intelligent one, a phenomenon that was more prevalent in fraternal twins than in identical twins.
By studying both identical and fraternal twins -- who only share half of their twin's DNA -- the effects of genes could be evaluated apart from other environmental factors shared by the twins such as diet.
"We found that the small relationship between intelligence and lifespan was almost all genetic," researcher Rosalind Arden, of the London School of Economics and Political Science, told Live Science.
There was a much larger difference in longevity between fraternal twins than identical twins, which researchers say proves genes are at play.
On the reasons for the findings, Arden said in a release: “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.”
But if you're not the smart one in the family, don't get worried just yet. “It’s important to emphasize that the association between intelligence and lifespan is small," Arden said in a statement. "So you can’t, for example, deduce your child’s likely lifespan from how he or she does in their exams this summer.”
Phew.
CORRECTION: An earlier version of this article incorrectly stated that identical twins only share half of their twin's DNA. It should be fraternal twins.