An Aspect of Personality that Predicts Longevity
Do psychological factors really predict longevity?
Posted Nov 21, 2010
One of the most intriguing studies was reported in 2010 by Howard Friedman, Margaret Kern, and Chandra Reynolds in the Journal of Personality. These authors traced a group of individuals who have been studied by psychologists since they were children in grade school in the San Francisco Bay Area, beginning in 1921-1922. Originally selected for their high intelligence, these individuals were studied by Professor Louis Terman, an eminent intelligence researcher of the time -- hence the group's name "Terman's Termites." In their young adulthood (average age 29), the Termites were measured using a number of personality scales; then they were studied again in 1986. Longevity data were collected by Friedman and his colleagues through 2007, all in all accumulating 67 years of follow-up.
The researchers asked, "Do qualities of an individual's psychology predict how long they live?" The answer is yes. Some of the characteristics are the same for men and women, and some vary by gender.
Two psychological variables in particular were studied in relation to longevity: Neuroticism and Conscientiousness. Neuroticism refers to the tendency to experience sadness, anger and anxiety, and to be oversensitive; its polar opposite quality is Emotional Stability. Conscientiousness refers to dutifulness, organization, and responsibility; its polar opposite quality is Carelessness.
I will limit my summary here to whether these two variables were related to longevity in the Friedman et al. study.
Longevity is particularly interesting to me because it provides an entirely non-subjective measure of health: how long you live. I am interested in this non-subjective index for one very important reason. Relationships between variables sometimes arise in psychological research that are due to subjective interpretations, as opposed to physical realities. For example, people who are Neurotic in outlook (e.g., anxious, sad, and hostile) often report worse health than Emotionally Stable people. It is unclear, however, whether people high in Neuroticism really have worse health than others, or whether their health is, biologically speaking, as good as anyone else's, but they don't regard it as good. Studying longevity eliminates the issue of subjectivity. If you are alive, you are alive (although there may, of course, be meaningful differences in one's quality of life).
In Friedman et al.'s follow-up study of the Termites, the trait of Neuroticism predicted poorer self-reported health, and less happiness, but Neuroticism was not related to longevity. That is, feeling anxious, sad, and hostile to varying degrees neither lengthened nor shortened the lifespans of the people in this sample. The picture was a bit different when the researchers analyzed the results for men and women separately. For men, a bit of neuroticism was marginally related to longer life, whereas for women it predicted a slightly higher risk of death. There are not many similar findings of gender differences in neuroticism and longevity like this one, so it is unclear why this should be so. The key finding here is for the overall sample: Neuroticism may make you worry about living a shorter life, but it will not actually lead to a shorter life.
Moving on from Neuroticism, the personality trait of Conscientiousness predicted longevity for the full sample (both men and women together). The more conscientious a person was, the longer he or she lived. When women and men were analyzed separately, the effect was more pronounced and certain for women, although it appeared to be present for men as well.
Why did conscientiousness predict longer life in this study (as it has in other studies)? People higher in conscientiousness tend to be more self controlled and dutiful. The current speculation is that those who are conscientious tend to follow standards of healthy living more than others: they exercise more, eat more healthily, and do what their doctors tell them to do.
These findings are intriguing because they indicate that certain psychological factors such as conscientiousness can predict greater longevity -- a decidedly non-subjective health outcome. Such findings are important to personality psychologists who argue for the importance of their discipline -- and also for any and all of us who hope to live a longer life. That is because personality traits such as conscientiousness can be gradually developed and improved, if one desires to do so.
Friedman, H. S., Kern, M. L., & Reynolds, C. A. (2010). Personality and health, subjective well-being, and longevity. Journal of Personality, 78, 179-215.
Copyright © 2010 by John D. Mayer