“Clear and compelling evidence” has been found to suggest that outlook and a positive demeanor could have a pretty significant impact on lifespan.
The review was of 160 previous studies regarding happiness, with being happy beating out even obesity as a lifespan-influencing factor. Professor Ed Diener of the University of Illinois led the review, and said the findings were consistent across the data:
“I was almost shocked, and certainly surprised, to see the consistency of the data… The general conclusion from each type of study is that your subjective wellbeing, that is, feeling positive about your life, not stressed out, not depressed, contributes to both longevity and better health among healthy populations.
“(The) overwhelming majority … support the conclusion that happiness is associated with health and longevity.”
Depression, pessimism and anxiety were linked in the data to shorter lifespan, as well as higher rates of disease and sickness. Diener commented:
“Happiness is no magic bullet, but the evidence is clear and compelling that it changes your odds of getting disease or dying young.”