Scientists have known for a while that people who score higher on intelligence tests tend to live longer. Until now, however, the precise link between smarts and longevity has been elusive. Some have suggested that the increased economic security that comes with high-paying, intellectually demanding jobs is responsible, while some suggest that more intelligent people are less likely to take risks that endanger their lives. 

Now, a British study has come along to suggest that rather than intelligence leading to longer life, the root of both variables may be in genetic factors. Scientists from the London School of Economics (LSE) used data from three studies of twins conducted in Denmark, Sweden and the U.S. The three studies included both fraternal and identical twins, but all the twin pairs were same-sex. Comparing fraternal and identical twins is especially useful for determining the scope of the influence of genetic factors on life outcomes.

The scientists found that an amazing 95 percent of the correlation between intelligence and long life was due to genetic factors. In other words, it's not intelligence in itself that lengthens a person's lifespan, it's the genetic traits underlying both characteristics. 

"Our research shows that the link between intelligence and longer life is mostly genetic," researcher Rosalind Arden of LSE said in a press release. "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, she emphasized that the association between intelligence and lifespan is still rather small, meaning that other factors have a much larger influence on longevity.

For more information about aging longevity, follow this blog or contact the Longevity Centres of America.