It’s fair to say that everyone wishes to live a longer life, but it's even better to live a long life that is a healthy one. Most people know what they need to do to achieve this goal, but they may not always follow the advice of their own inner guidelines. It’s all too easy to skip your early morning workout, sneak in a doughnut during a coffee break, or indulge in an extra glass of wine during a particularly tasty meal. Perhaps, though, you practice what health experts preach, and you’re able to resist these temptations without any difficulty at all. Your eye is on the prize of a long and healthy life, a goal that you believe can be under your control.
Researchers in behavioral medicine and health recognized decades ago that personality must be taken into account in understanding the factors which influence adopting a life-prolonging lifestyle. This field originated in the now-classic, though imperfect, studies on the “Type A Behavior Pattern,” in which hard-driving, impatient, achievement-oriented, and super-punctual individuals appeared to have higher risk of cardiovascular disease than their laid-back Type B counterparts. Researchers continue to expand on related personality and behavior patterns, with the latest entry being the “Type D” (for distressed), which refers to people who suppress their negative emotions, compromising their recovery from a cardiovascular event. More generally, however, researchers are interested in the overall personality traits or dispositions that can affect people’s health through lifestyle risk factors.
The most recent investigation of the health-personality link has tackled the problem by studying over 131,000 individuals making up cross-national samples of different cohorts from Australia, Germany, the United Kingdom, and the United States. Markus Jokela and colleagues (2019), from the University of Helsinki (Finland), based this tour-de-force analysis of personality’s relationship to health outcomes on the Five Factor Model of personality, also known as the “OCEAN” model: Openness to Experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism. As the Finnish-led team of researchers note, previous evidence supports a link between individual differences in personality and—the ultimate measure of health—mortality risk. For example, people low in Conscientiousness have a 14% higher mortality rate because their low self-control, lack of planning, and general irresponsibility “lead to unhealthy life choices and risk taking” (p. 1). There are weaker associations for the other 4 factors, but all are in expected directions.
Despite the fact that the mortality risks are now relatively well-documented, Jokela and his fellow researchers believe there is room for improvement by quantifying the relationships to personality by using life expectancy, an “absolute population metric.” In other words, mortality rates may be affected by the age of the samples, but life expectancy takes age (a risk factor for mortality) into account. Additionally, as the authors note, mortality or even life expectancy only tells part of the story. You don’t want just to live to be old, you want to live without disease and disability. “A long life is valuable, but a healthy and fully functional long life is even more valuable” (p. 2), as they very astutely maintain. To be able to connect the dots among personality, life expectancy, and disability-free years, Jokela and his fellow researchers needed to take a longitudinal approach, examining the long-term outcomes associated with baseline measures of personality. With the longest-running follow-up occurring 22 years later (averaging 7.2 years), these outcomes included, among survivors, measures of activities of daily living (ADL) as assessment of disability status. The researchers connected baseline with mortality data over progressive years of the study.
With these extensive datasets available to them, the research team was able to construct survival analyses, predicting both mortality and disability status from those baseline personality scores. As you might expect, the researchers also needed to control for the lifestyle factors of heavy alcohol consumption, physical inactivity, body mass index, and education in the personality-mortality-disability connection.
Supporting the role of personality on life expectancy and disability-free years, the main findings to emerge from the survival analyses supported the roles of personality as an influence on life expectancy and, just as importantly, healthy life expectancy. Individuals who had the very lowest scores on Conscientiousness at baseline lived, on average, 6 fewer years than their more careful and fastidious counterparts, and for those last two years of their lives, were also more laden with disability. Moving up the Conscientiousness scale, each increase in this trait was associated with longer life expectancy and fewer years of disability.
Looking at the whole population, the authors also concluded that if everyone in their respective countries were high in Conscientiousness, the average population’s life expectancy would have been 1.3 years longer; importantly, most of that time (one year) would be spent disability-free. The other personality trait to emerge as a predictor of healthy years of life was Neuroticism, but only for those at the extreme end of the scale.
What about those lifestyle factors? As it turned out, 25% of the Conscientiousness effect on life expectancy could be accounted for by the three factors of smoking, body mass index, and low physical activity. The bad news is that if you resign yourself to being a slacker in the lifestyle department, your life will be shorter and more laden with disability. However, the flip side is that if you can force yourself to adopt healthy habits, you can offset in part the otherwise detrimental effects on your well-being and longevity. As the authors concluded, “we hypothesize that multiple health risks and risky behaviors accumulate at the low end of the Conscientiousness distribution” (p. 8). For those at the highest end of the Neuroticism scale, the authors suggest that “severe mental disorders may be one of the mediating mechanisms” leading to fewer disability-free years (p. 8), given that people with these disorders appear to have poorer physical as well as mental health.
The final piece of the puzzle is that question of causality and whether the factors associated with lower life expectancy are determined by personality or whether poorer health habits lead to negative personality changes. However, the authors were able to rule out disability as the cause of personality changes by performing a set of backwards comparisons of those who lived and those who died. Remaining unanswered is whether a common genetic or environmental factor is the cause of both poorer health and shorter life expectancy as well as less adaptive personality traits, a question that will need to be addressed in future research.
To sum up, whatever the direction of causality, the findings clearly highlight the importance of maintaining healthy lifestyle habits. You may feel that your personality is what it is, and can’t be changed, so you’re fated to develop life-threatening health conditions based on where you fall on the Conscientiousness and Neuroticism continuums. However, knowing that you can offset what may be a high-risk personality by making several lifestyle changes should help give you the motivation you need to life a longer, and more fulfilling, life.
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Jokela, M, Airaksinen, J, Virtanen, M, Batty, GD, Kivimäki, M, Hakulinen, C. Personality, disability‐free life years, and life expectancy: Individual participant meta‐analysis of 131,195 individuals from 10 cohort studies. Journal of Personality. 2019; 00: 1– 10. https://doi.org/10.1111/jopy.12513