Quotes of the Day

It's getting tougher these days to think of the glass as half full rather than half empty, but if you're going to survive this economic crisis — literally — you might as well try.

That's the lesson from a large study of death rates in optimistic vs. pessimistic women, conducted by researchers at the University of Pittsburgh. Using data from the Women's Health Initiative, an ongoing government study of more than 100,000 women over age 50 that began in 1994, the team found that eight years into the study, optimistic women were 14% more likely to be alive than their pessimistic peers. (See pictures of women around the world.)

The participants were asked to answer a standard questionnaire that measured optimistic tendencies based on responses to statements like "In uncertain times, I expect the worst." Those scoring highest in optimism on this scale were more likely to be alive eight years later, while those with the lowest, most pessimistic scores were more likely to have died from any cause, including heart disease and cancer.

At first blush, that's not such a surprise, considering that optimistic people, being more hopeful overall, probably eat better, work out more and make regular visits to the doctor. Previous studies have indeed documented the life-extending benefits of optimism, although most of that research has involved men and has been conducted in small numbers. What's more, not all studies have done a good job of weeding out potentially confounding factors such as health status and lifestyle. That's what makes the new study different. "Taking into account income, education, health behaviors like [controlling] blood pressure and whether or not you are physically active, whether or not you drink or smoke, we still see optimists with a decreased risk of death compared to pessimists," says Dr. Hilary Tindle, lead author of the study. "I was surprised that the relationship was independent of all of these factors." (Read "The Truth About Women, Money and Relationships.)

So if the women's lifestyle doesn't explain their longevity, what does? While the study was not designed to tease out specific factors, Tindle proposes several potential explanations, which she hopes to validate in further trials: optimistic people have more friends and a larger social network on which they can rely during crises; they also tend to cope better on their own with stress, a risk factor that has been associated with high blood pressure, heart disease and early death in previous studies. It isn't entirely clear how optimists manage stress so well, but it may have something to do with their physiological makeup — genes and metabolic processes that keep them from panicking during troubling times. Or it may simply be that optimists follow medical advice more faithfully than pessimists, giving them a better chance of staving off life-threatening disease. "Our study reveals interesting findings. Now we need to replicate them and find out why this association is happening," says Tindle.

Another interesting trend that emerged from Tindle's analysis was the difference in longevity between white and black women. Pessimistic black women in the study were 33% more likely to have died after eight years than optimistic black women, while white pessimists were only 13% more likely to have succumbed than their optimistic counterparts. The numbers in the study weren't large enough to support any definitive explanations for this racial gap, but "there is definitely a suggestion that whites and blacks may be different in how optimism affects longevity," says Tindle.

It's also worth noting that the current report identifies only an association between optimism and longevity; it does not actually establish whether optimism can directly cause a longer life. Additional research will have to be done in order to answer that question. But if a sunnier disposition helps promote healthy behaviors like eating well and exercising regularly, then there's no reason not to view the glass as half full.

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• Alice Park
• A new study suggests that pessimistic women are more likely to die sooner than optimistic ones. Too bad optimism is so hard to come by