Pssst. Want the secret to a long life? Here.

A new book, “The Longevity Project,” may hold some answers.

The New York Times takes a peek:

After reading “The Longevity Project,” I took an unscientific survey of friends and relatives asking them what personality characteristic they thought was most associated with long life. Several said “optimism,” followed by “equanimity,” “happiness,” “a good marriage,” “the ability to handle stress.” One offered, jokingly, “good table manners.”

In fact, “good table manners” is closest to the correct answer. Cheerfulness, optimism, extroversion and sociability may make life more enjoyable, but they won’t necessarily extend it, Howard S. Friedman and Leslie R. Martin found in a study that covered eight decades. The key traits are prudence and persistence. “The findings clearly revealed that the best childhood personality predictor of longevity was conscientiousness,” they write, “the qualities of a prudent, persistent, well-organized person, like a scientist-professor — somewhat obsessive and not at all carefree.”

“Howard, that sounds like you!” Dr. Friedman’s graduate students joked when they saw the statistical findings. On a recent visit to New York, Dr. Friedman and Dr. Martin did both seem statistically inclined to longevity. Conscientiousness abounded. They had persisted in a 20-year study — following up on documentation that had been collected over the previous 60 years by Lewis Terman and his successors — despite scoffing from students: Get a life!

The hotel room (Dr. Martin’s) was meticulously neat, and they had prudently ordered tea and fruit from room service. Both were trim and tanned, measured in their answers, trading off responses like the longtime collaborators they are. Despite a busy schedule they were organized enough for a relaxed talk.

In 1990, Dr. Friedman and Leslie Martin, his graduate student at the time, realized that an invaluable resource for studying well-being and longevity existed right in their own state of California. In 1921, Dr. Terman had chosen 1,528 bright San Francisco 11-year-olds for a long-term study of the social predictors of intellectual leadership. Dr. Terman interviewed the children, their families, their teachers. He studied their play habits, their parents’ marriages and their personalities: were they diligent, extroverted, cheerful? He and his team followed up with the participants every five or 10 years. Dr. Terman died in 1956, but colleagues continued the regular interviews with the original subjects, asking the same questions Dr. Terman had asked.

Dr. Friedman and Dr. Martin pored through Dr. Terman’s records, dredged up death certificates and asked Dr. Terman’s questions of study participants’ survivors. They also conducted a group analysis of other similar studies, and collaborated with experts in many fields.

The secret to a long life has been much studied. The health economist James Smith, at the RAND Corporation, found that the answer was education. Stay in school. This is no doubt true. But his findings don’t necessarily conflict with Dr. Friedman and Dr. Martin’s: what keeps people is school is often conscientiousness.

Read more.