- Among the "Big Five" personality traits, conscientiousness is especially predictive of living a longer life.
- The personality trait has also been linked to health-related behaviors such as smoking and sleep, which may help explain its relation to longevity.
- Recent research suggests conscientiousness is also related to immune system function.
One reason scientists and laypersons alike are interested in personality is that the concept is so intuitive. It corresponds to our basic observation that individual behavior is organized into patterns and that those patterns vary between individuals.
Science, for its part, is interested in description, and personality models describe people—and the differences between them—in useful ways. A popular and well-studied model is the Big Five, which measures five basic and relatively stable traits: Neuroticism, Openness, Agreeableness, Extraversion, and Conscientiousness. Individual differences in levels of these traits are assumed to account for observed differences in patterns of behavior.
Yet science and laypeople alike are also interested in prediction, in using one variable to forecast another, in peering into the future. Personality, it turns out, can help us do that as well. Big Five personality trait measures are predictive of varied aspects of people’s lives, from Internet usage to academic achievement to marital satisfaction.
One outcome domain attracting much attention among personality researchers is longevity. Over the past 30 years, evidence has accumulated to suggest that aspects of personality indeed predict longevity, and that personality-related differences in this outcome are comparable in size to those linked to socioeconomic status and intelligence.
For example, the psychologists Stephen Soldz and George Vaillant of Harvard Medical School (1999) examined data from 163 men followed prospectively for over 45 years. They found that “Conscientiousness in college was the best predictor of what happened to the men in the future, whereas Neuroticism in late midlife was the best correlate of life course functioning across a variety of domains.”
Howard Friedman and colleagues at the University of California, Riverside (2010) studied a sample of 1,312 participants who were assessed for personality as young adults in 1940. The researchers then assessed participants' healthy aging in 1986, and collected their death certificates through 2007 to measure longevity. Analysis of these data showed that “neuroticism predicted worse physical health and subjective well-being in old age and, for women, higher mortality risk, but for men, neuroticism predicted decreased mortality risk. For both sexes, extraversion predicted old-age social competence, whereas conscientiousness predicted men’s old-age productivity.”
Reviewing (2011) the links between personality traits and longevity, Benjamin Chapman of the University of Rochester and colleagues concluded, “there is good evidence that higher level of conscientiousness and lower levels of hostility and Type D or 'distressed' personality are associated with greater longevity. Limited evidence suggests that extraversion, openness, perceived control, and low levels of emotional suppression may be associated with a longer lifespan. Findings regarding neuroticism are mixed, supporting the notion that many component(s) of neuroticism detract from life expectancy, but some components at some levels may be healthy or protective. Overall, evidence suggests various personality traits are significant predictors of longevity.”
Jason Strickhouser and colleagues (2017) conducted a "metasynthesis" (analysis of multiple meta-analyses) to examine relations between personality traits and health variables in over 500,000 participants. They found that “when entered simultaneously, the Big Five traits were moderately associated with overall health... effects were larger among agreeableness, conscientiousness, and neuroticism than extraversion or openness to experience.”
Conscientiousness Stands Out as a Predictor of Longevity
Over time, the evidence regarding longevity has converged quite decidedly on one particular Big Five trait: conscientiousness. For example, Howard Friedman and colleagues (1993) used personality data from 1,178 males and females involved in a 70-year longitudinal study initiated by Lewis Terman in 1921. They found that “conscientiousness in childhood was clearly related to survival in middle to old age.”
Mining the same data set, Leslie Martin and colleagues (2007) conducted a prospective longitudinal cohort study of 1,253 male and female Californians over seven decades (1930-2000), finding that “conscientiousness, measured independently in childhood and adulthood, predicted mortality risk across the full life span.”
Margaret Kern and Howard Friedman of the University of California, Riverside (2008) conducted a meta-analysis of the association between conscientiousness and longevity involving 20 independent samples with 8,942 participants from six different countries. Results showed that "higher levels of conscientiousness were significantly and positively related to longevity."
Reviewing the evidence linking conscientiousness to health and longevity, Tim Bogg (Wayne State) and Brent Roberts (University of Illinois) (2014) concluded that “accumulated evidence supports greater integration of conscientiousness into public health, epidemiological, and medical research, with the ultimate aim of understanding how facilitating more optimal trait standing might foster better health.”
Recently, Nicholas Turiano of West Virginia University and colleagues (2020) integrated data from 44,702 participants in 12 different cohort studies to find that “a consistent pattern emerged of higher levels of conscientiousness predicting a reduced hazard of dying.”
Why Do Conscientious People Tend to Live Longer?
So, when it comes to longevity, the trait of conscientiousness appears to be the most consequential predictor. But scientists and laypersons are not only interested in prediction; we also want to explain—to know why things relate in the way they do. Beyond mere description and prediction, explaining the phenomena of the world is the apex of scientific ambition. So, how may conscientiousness bring about longevity?
Generally, complex human outcomes are multi-determined, which means that personality factors may exert their influence on longevity through various pathways. One such pathway runs from personality to behavior to longevity. Research has documented that personality traits predict certain health behaviors, such as smoking, diet, exercise, alcohol use, and risk-taking, which in turn are known to affect longevity.
For example, Sarah Hampson and colleagues (2006) at the University of Surrey in Great Britain examined teachers' personality assessments of 963 elementary school children. They then assessed participants’ smoking, alcohol use, body mass index (BMI), and self-rated health 40 years later. “Childhood personality traits were significantly associated with all four outcomes.” Higher conscientiousness was related to less smoking in adulthood and, for women, lower BMI.
Shantel Spears (2019) at West Virginia University and colleagues have recently argued that personality may also affect longevity through its effects on sleep. Their 20-year study involving 3,759 participants found that “lower conscientiousness predicted increased death risk via the direct, indirect, and total effect of… sleep duration.”
Conscientiousness is also likely to affect longevity via biological pathways. Indeed, Angelina Sutin of Florida State University and colleagues (2018) analyzed a sample of over 12,000 participants for the link between biological markers of health—including body mass index, waist circumference, blood markers (A1c, HDL cholesterol, etc.), and physical performance (lung function, grip strength, walking speed)—and various correlated facets (components) that constitute the conscientiousness trait (self-control, order, industriousness, traditionalism, virtue, and responsibility). Results showed “four of the six facets of conscientiousness were associated with nearly all of the health markers." Higher conscientiousness predicted "healthier metabolic, cardiovascular and inflammatory markers, and better performance on physical assessments.”
Yannick Stephan of Euromov University in France and colleagues (2019) obtained seven-year mortality data from over 11,000 participants, evaluating the facets of conscientiousness, as well as demographic factors, disease burden, smoking, and physical inactivity. They found that, controlling for demographic factors, the industriousness facet alone “was associated with an almost 25 percent lower likelihood of mortality.”
Most recently (2021) Páraic Ó Súilleabháin at the University of Limerick and colleagues provided evidence that personality may affect longevity through a person’s immune function. Their study looked at two biological markers—interleukin-6 and c-reactive protein—known to factor in age-related morbidity in a sample of 957 adults examined over a 14-year period. Results suggested that "part of the reason why people who score higher on the personality trait of conscientiousness live longer is as a result of their immune system, specifically due to lower levels of a biological marker called interleukin-6.”
High conscientiousness, then, appears to pay off in terms of improved longevity through multiple behavioral and biological pathways. So, how conscientious are you? A brief Big Five trait assessment can be found here. If you’re low on conscientiousness, there is still hope. One can learn to become more conscientious through purposeful practice. Psychotherapy can also help improve conscientiousness. Finally, research has shown that personality in general and conscientiousness, in particular, can change, and tend to improve with age. So, your low conscientiousness could improve on its own over time—that is, if it doesn’t kill you first.
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