What would happen if you asked 7,000 people about their work hours, and then followed their progress for the next 12 years? What could you predict based on that one little fact?
Quite a lot, actually. High achievers in science and business typically put in at least 60 to 70 hours, every week of the year, according to the author of Greatness, University of California Davis psychology professor and achievement maven, Dean Keith Simonton. Among Nobel prize winners, that figure is about 100 hours a week and then, of course, there's the 10,000-hour rule, popularized by Malcolm Gladwell in his book, Outliers. There's no escaping the fact that hard work reaps big benefits.
But there's a downside: Long work hours are linked to a shorter lifespan. We have long known that ambitious, barracuda types are more prone to develop heart disease than the average nine-to-fiver. Fifty years ago, cardiologists Meyer Friedman and Ray Rosenman coined the term Type A personality to describe the style of their typical patient - usually a guy who got worked up too easily, was competitive, a perfectionist, and always in a rush (the doctors spent a fortune each year reupholstering their waiting-room chairs; the arms and seats having been clawed to shreds by impatient Type As). The doctors found that combined with other risk factors - such as smoking and lack of exercise - a person with this profile was more likely than other folks to self-implode because of a heart attack by age 50.
Now that cigarettes are out and fitness is in, though, that stereotype doesn't resonate with too many of us. But drive still rules the business world. So what about the fit team player who simply puts in incredible hours every day?
A recently published long-term study led by Mika Kivimaki, an epidemiologist at University College London, shows that no matter how healthy a person is, simply putting in an extra hour after an eight-hour day increases the risk of heart attack by 20 per cent. The more stunning finding is about workaholics: People who put in 11 hours or more a day increase their cardiovascular risk by a whopping 67 per cent. It's not a matter of personality as much as a matter of hours - though, of course, the two factors might be related.
Prof. Kivimaki's team is part of the so-called Whitehall II study, which has been tracking the health and lifestyle choices of 10,000 British civil servants since 1985. The research team selected 7,100 of these workers (2,109 women and 4,896 men) who had no previous history of health or heart problems. The participants were given thorough medical exams in 1992-1993, and were asked about their daily habits, including their average weekday work hours, including work they took home. Then the researchers watched what happened to them, assessing them at regular intervals to see which lifestyle factors were the best fortune tellers. Among the 7,100 middle-aged working adults, who would still be in good shape in 12 years? Who would have had a heart attack? Who would have died in the interim?
Fifty-four per cent of the subjects worked a standard seven- to eight-hour day, and 10 per cent worked 11 hours or more. That 10 per cent (whom Mr. Gladwell might call outliers) showed a "remarkable increase in the risk of heart disease," said Prof. Kivimaki, adding: "This new information should be a wake-up call for people who overwork themselves, especially if they already have other risk factors."
The risks of long hours aren't hypothetical. Other long-term studies of the work force in Europe and Asia have found that people who work 11 hours or more a day are courting death. In the Kivimaki study, all the participants were healthy and under 62. Yet during the 12 years they were monitored, 163 of them had non-fatal heart attacks, and 29 of them died after cardiac events/heart attacks. Even those of us who love our jobs might wonder whether the tradeoff is worth it.
Here's what we don't know, however. We can't say that long work days caused these cardiac events - only that those who were willing to put in the brutal hours were more likely to pay the ultimate price. For outliers such as musician Glenn Gould, chess master Bobby Fischer and NBC broadcaster Tim Russert - all felled by heart attacks before the age of 65 - we'll never know whether the thrill of achievement justified the long hard slog that preceded it, and the mortal risks that came along for the ride.
Susan Pinker is a psychologist and author of The Sexual Paradox: Extreme Men, Gifted Women and the Real Gender Gap.