Optimism

Research summary

• Dispositional optimism has one of the more consistent bodies of prospective evidence linking a psychological trait to mortality.
• A 2019 meta-analysis pooling 15 cohort studies and 229,391 participants over a mean 13.8-year follow-up found optimism was associated with a 14% lower risk of all-cause mortality (relative risk 0.86) and 35% lower risk of cardiovascular events (RR 0.65); a second independent meta-analysis of six cohorts (n=181,709) found a similar 13% mortality reduction (hazard ratio 0.87).
• The flagship cohort study — pooling the Nurses' Health Study and the VA Normative Aging Study — found the most optimistic quartile of women lived 14.9% longer than the least optimistic, with 1.5-1.7 times greater odds of surviving to age 85, a finding replicated in 159,255 women across multiple racial/ethnic groups in the Women's Health Initiative (5.1-7.6% longer lifespan depending on group).
• Effects were also seen specifically in Black Americans in the Jackson Heart Study, and were maintained, though attenuated, after adjusting for health behaviors and depression in the Nurses' Health Study (hazard ratio moving from 0.71 unadjusted to 0.91 adjusted).
• Not every study agrees: a cohort of adults 70 and older (ASPREE/ALSOP, n=11,701) found no significant association in the full sample, and a benefit only in those already 77 or older.
• All of this evidence is observational — optimism could be a marker of good health as much as a cause of it, and no trial has tested whether deliberately increasing optimism extends life.