To live a long life, we've been told, eat well, exercise and manage stress. Now an eight-decade study indicates that's only part of the equation. Health scientists Howard Friedman and Leslie Martin explain how factors such as social connections, personality and marriage affect long-term health in The Longevity Project.
Friedman and Martin drew upon the work of Stanford University psychologist Lewis Terman, who began studying intellectual leadership in 1921. Terman selected about 1,500 of the brightest boys and girls he could find and tracked them throughout their lives. He collected all sorts of information about the children and their families — from how many books were in their houses, to their dispositions.
Terman died in 1956, but the project was carried on by others. Friedman and Martin picked up on his work in 1990, and used the decades of data gathered to better understand health and longevity.
"Everyone knows," Friedman tells NPR's Jennifer Ludden, "that some people are more prone to disease, and they take longer to recover and they live shorter lives, when their seemingly comparable friends and associates thrive." Genetic factors offer part of the explanation for why — about one-third, he says — but there's much more to it.
Take disposition, for example. Cheerful and optimistic children are actually less likely to live long lives, they found.
"The most cheerful, optimistic kids grew up to take more risks," explains Martin. "By virtue of expecting good things to happen and feeling like nothing bad ever would, they predisposed themselves to be heavier drinkers, they tended to be smokers, and their hobbies were riskier."
So, she concludes, "some degree of worrying actually is good." And, in fact, adds Friedman, "the prudent, persistent, planful people — both in childhood ... and then in young adulthood we measured that — that was the strongest individual difference, or personality predictor, of long life."
And it's not just about risk aversion. The study found that conscientious people developed better social relationships and accomplished more at work. Think all that responsibility sounds boring? Not so, says Martin. "Because of those qualities, they tended to get nice opportunities in life, and so they went on to live some of the most exciting and interesting lives of anyone in the study."
Often, with responsibility comes stress, something we're typically advised to avoid. But some stress is not a bad thing, says Martin. When study participants who had stressful jobs "found meaning in those jobs and they were committed to them, that stress really didn't hurt them. They thrived in spite of — or perhaps with the aid of — it."
Friedman and Martin also found that the conventional wisdom on fitness isn't quite right. If we try too hard to push ourselves into exercise regimens, it can backfire. Physical activity is important, they found, but it's more about doing what you love than adhering to a certain fitness program.
And for adults who have fallen into sedentary lifestyles, it's not too late. In middle age, "if you can pick up some activity you like — it doesn't have to be going to the gym every morning — that really has a big impact on the rest of your life," says Friedman.
"We're really talking here about the difference between people who become sick and die in their 50s and 60s," he says, "versus those who thrive into their 70s, 80s and 90s."