Are you an optimist? Congratulations, you’ll probably die younger than
pessimists. Researchers started off studying 1,500 children, following them
through their adult lives and eventually concluded that the most cheerful
kids had shorter lives overall than those who were less cheerful. A likely
explanation is that cheerful people are more likely to take potentially
life-shortening risks.
Source: Longevity Project, 10/22/12