The power of positive thinking: optimists live longer

Using data from 100,000 women over age 50, the Women's Health Initiative, which began in 1994, found that self-described optimists were more likely to be alive after the first eight years of tracking participants' health. While these optimists were less likely to die from any cause, research found that 30 percent of participating women were less likely to die from heart disease, the leading cause of death in women in the US. Conversely, pessimistic women had a "higher overall death rate," and they were also 23 percent more likely to die from conditions related to cancer.

Researchers believe that optimists in general have larger social networks to turn to during crises, and that they just cope better with stress, which has been associated with heart disease.