THE GLASS IS HALF-EMPTY

Pessimism can lead to a longer life. German researchers asked 40,000 people ages 18 to 96 to rate how happy they thought they’d be in five years on a scale of zero to 10. Checking in five years later, they found that every point by which a person had overestimated his or her future well-being corresponded to a 10 percent higher likelihood of death or disability within the study period. “Pessimism about the future may encourage people to live more carefully, taking health and safety precautions,” says psychologist Frieder Lang.