Researchers from the London School of Economics published their findings on the link between intelligence, genes, and longevity in the International Journal of Epidemiology.
For their study, the researchers compared the genetics of fraternal twins with identical twins, being fully aware that fraternal twins only share half of the DNA — this way researchers were better able to understand the impact of genetics separate from variables such as environment, home life, school, and childhood nutrition.
They found that within these twin sets, the twin who was more intelligent tended to live longer than the twin who wasn't as bright, and that this was especially true with fraternal twins.
"We know that children who score higher in IQ-type tests are prone to living longer," said Rosalind Arden, research associate at the London School of Economics and Political Science in a press release. "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."
Arden's tem collected data from three different twin studies in Sweden, the United States, and Denmark. Within these three studies, age of death and overall intelligence were recorded, and at least one twin from each pair had passed away. In addition, all the twin pairs were same-sex.
There have been numerous studies in the past regarding the link between intelligence and a long life, but the link wasn't clearly defined before Arden and her colleagues' study.
"Our research shows that the link between intelligence and longer life is mostly genetic," said Arden.
But parents should absolutely take this information with a grain of salt.
"It's important to emphasize 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," Arden said.
Can you imagine if looking at summer school grades was a way to predict how long we'd live? My parents would've been convinced I'd have a very short life, as I flunked algebra the summer of 9th grade.
When considering the connection between the genetics of being smarter and living longer, Arden says, "If 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."
Once again, it all comes down to good genes. Hey, if you're a smart person, thank your parents for that.