Positive emotions extend life expectancy by ten years

The more positive your attitude to life is - the more optimistic, upbeat, content and happy you are - the longer you are likely to live. According to researchers on the aging process at the University of Kentucky, a positive attitude to life can add more than a decade to your life expectancy. The researchers base this bold assertion on research done on 180 nuns.

Positive emotions & life span
That there's a relationship between emotions and life expectancy is not so strange. Negative emotions, such as sadness, fear, disgust and worry raise the heart beat and blood pressure and increase the likelihood of cardiovascular disease.

Conversely, positive feelings such as optimism inhibit the negative impact of stress on the cardiovascular system. If your future outlook is positive, negative events will cause less stress.

But life expectancy is determined by many more factors, such as marital status, social activities, smoking and alcohol, access to medical facilities and physical activity. Thats why the researchers decided to study nuns; they all live largely the same kind of lifestyle. That makes it easier to focus on the presence of positive emotions.

Study
Between 1991 and 1993 the researchers approached all the nuns of the School Sisters of Notre Dame who were still alive and had been born before 1917. That meant they were all between 75 and 102 years old.

In 1930, when the sisters were between 18 and 32, they had been asked to write a short autobiography by their Mother Superior. The researchers decided to analyse the autobiographies of 180 nuns who had lived in convents in Milwaukee and Baltimore.

Results
The researchers looked on the one hand at sentences with "low positive emotion", sentences with "high positive emotion", the number of words that reflected positive emotions and the number of kinds of positive emotions, and at life expectancy on the other hand. When they divided the nuns up into quartiles they noticed that it was above all the number of positive emotions that influenced life expectancy.

Nuns that had written about the most different types of positive emotions had a four times lower risk of mortality than the nuns who expressed the fewest positive emotions. The difference in life expectancy between these two groups was 10.7 years.

The figure below shows the survival curves of the four groups of nuns. Quartile 1 is the group of nuns with the lowest number of sentences describing a positive emotion; Quartile 4 is the group of nuns with the highest number of positive sentences. The life expectancy of the nuns in Quartile 4 exceeded that of the nuns in Quartile 1 by 6.9 years.

The researchers calculated that for every one percent increase in the number of positive sentences the nuns' mortality risk decreased by 1.4 percent.

The researchers were surprised at the strength of the effect they found. They suspect that scientists have not noticed this before because a positive attitude to life is often associated with unhealthy behaviour. It's only likely to emerge if you study groups of people who are unable to live unhealthy lifestyles - like nuns.

Conclusion
"One behavioral pathway is suggested by the study by H. S. Friedman [Personality and Longevity: Paradoxes. In: Research and Perspectives in Longevity 1999, pp 115-122.] in which cheerful participants were more likely to engage in behaviors that are health risks such as excessive drinking and smoking. Such a pathway would be expected to disrupt the potential physiological benefits of a pervading pattern of positive emotional responsiveness", they write.

"In contrast, all participants in the current study had lived a lifestyle in which such health-risk behaviors were improbable and therefore the physiological impact of a positive emotional style was almost certainly enhanced."

Reference: J Pers Soc Psychol. 2001 May;80(5):804-13.