About 95 percent of the relationship between intelligence and longevity is explained by genetic influences on both traits, researchers reported July 26 in the International Journal of Epidemiology. The study was somewhat limited in that most of the participants took intelligence tests during middle age, rather than in their youth. By that time, the IQ results might be skewed by the cognitive decline of aging.
Nevertheless, the researchers say, the results suggest that brighter people don’t just live longer because they make healthier choices, or make more money that affords them better health care. Rather, they live longer because their genetic makeup favors both smarts and a long life.
“We found that the small relationship between intelligence and life span was almost all genetic,” said study researcher Rosalind Arden, a research associate at the London School of Economics and Political Science.
Brains and life span
Studies large and small have linked smarts with the likelihood of living to old age. For example, a study of people born in Scotland that was published in 2001 in the British Medical Journal found that the higher people scored on an IQ test at age 11, the more likely they were to survive to at least age 76. In 2007, a paper in the Journal of Health Economics found that Nobel Prize winners slightly outlived runners-up. The researchers concluded that the prize money was not the reason for the winners’ longer life spans, but that the raised social status conferred by the prize might have been.