Optimistic individuals live up to 15% longer on average than their less optimistic peers, perhaps due to additional resilience, according to researchers from Boston University, Harvard University and VA Boston Healthcare System.

The investigators surveyed about 70,000 men and women, following the male subjects for 30 years and the female subjects for a decade. Along with greater overall odds of a longer lifespan, the most optimistic individuals had up to a 70% greater chance of reaching 85 years old and older when compared to the least optimistic groups.

The results accounted for age, demographic factors such as educational attainment, chronic disease, depression and health behaviors, such as alcohol use, exercise, diet and primary care visits.

Little is known about the psychosocial factors that lead to healthy aging, wrote co-senior author Laura Kubzansky, Ph.D., Harvard. But it’s been shown that an optimistic outlook allows people to better manage their emotions and bounce back from stress more effectively. Optimistic people are also more likely to have healthier habits, such as exercising, and are less likely to smoke, which may extend lifespan, she and her colleagues noted.

“[T]he link between optimism and health is becoming more evident,” added co-senior author Fran Grodstein, ScD.

The study was published in the journal Proceedings of the National Academy of Sciences.