Optimism and survival

It's obvious that healthy people live longer than sick people. If optimism actually improves health, it should also boost longevity — and according to two studies from the U.S. and two from the Netherlands, it does.

The first American study evaluated 839 people in the early 1960s, performing a psychological test for optimism""pessimism as well as a complete medical evaluation. When the people were rechecked 30 years later, optimism was linked to longevity; for every 10-point increase in pessimism on the optimism–pessimism test, the mortality rate rose 19%.

A newer U.S. study looked at 6,959 students who took a comprehensive personality test when they entered the University of North Carolina in the mid-1960s. During the next 40 years, 476 of the people died from a variety of causes, with cancer being the most common. All in all, pessimism took a substantial toll; the most pessimistic individuals had a 42% higher rate of death than the most optimistic.

The two Dutch studies reported similar results. In one, researchers tracked 545 men who were free of cardiovascular disease and cancer when they were evaluated for dispositional optimism in 1985. Over the next 15 years, the optimists were 55% less likely to die from cardiovascular disease than the pessimists, even after traditional cardiovascular risk factors and depression were taken into account.

The other study from Holland evaluated 941 men and women between the ages of 65 and 85. People who demonstrated dispositional optimism at the start of the study enjoyed a 45% lower risk of death during a nine-year follow-up period.