If you tend to see the glass half empty, this article may convince you to change your philosophy. Using data collected from over 70,000 people, a team of researchers, mostly from the Boston University School of Medicine, have highlighted the role that optimism may play in life expectancy.

Work on exceptional longevity has so far often focused on biomedical factors while the positive influence of psychosocial factors on healthy aging remains much less clear. This is what motivated Lewina O Lee and her colleagues to study the possible effects of optimism on longevity. They hypothesized that (very) optimistic people would live longer. To test this, they relied on data from two cohorts. The first concerns 69,744 women from the Nurses’ Health Study and the second looked at 1429 men from the Normative Aging Study on veterans. The participants answered various questions about their overall health, eating habits, alcohol consumption, smoking, but also their degree of optimism. These large, longitudinal surveys were carried out over 10 years (2004 à 2014) for women and 30 years for men.

Using these data and statistical correlations, the scientists then compared the levels of optimism in the different participants. What did they observe? When compared to those with the lowest levels of optimism, those with the highest levels of optimism had an average life expectancy that was 11 to 15% longer and were 50 to 70% more likely to achieve what the authors refer to as “exceptional longevity:” living past 85 years. After crossing the results with multiple factors, it should be noted that these results were confirmed even when accounting for socio-economic status, health problems, depression, social networks, and health-related behaviors (diet, eating habits, alcohol, smoking).

According to Lewina Lee: “This study has strong public health relevance because it suggests that optimism is one such psychosocial asset that has the potential to extend the human lifespan. […] Interestingly, optimism may be modifiable using relatively simple techniques or therapies.”

The authors acknowledge that they do not know exactly how optimism increases longevity. They cite other research that suggests that optimistic people are better at regulating their emotions and stress. Scientists also believe that optimists are more likely to adopt healthier habits (regular exercise, less smoking), which could lead to longer lives. In addition, a recent study by R. Hernandez and colleagues (2019), carried out on 3,500 people (ages 32 to 51), showed that optimists also sleep better.

In conclusion, while the positive effects of optimism require further research, according to the authors, this psychosocial factor is becoming increasingly evident.