Objective
To examine the personality trait conscientiousness as a risk factor for mortality and to identify candidate explanatory mechanisms.
Methods
Participants in the Whitehall II cohort study (N = 6800, aged 34 to 55 at recruitment in 1985) completed two self-reported items measuring conscientiousness in 1991–1993 (‘I am overly conscientious’ and ‘I am overly perfectionistic’, Cronbach's α = .72), the baseline for this study. Age, socio-economic status (SES), social support, health behaviours, physiological variables and minor psychiatric morbidity were also recorded at baseline. The vital status of participants was then monitored for a mean of 17 years. All-cause and cause-specific mortality was ascertained through linkage to a national mortality register until January 2010.
Results
Each 1 standard deviation decrease in conscientiousness was associated with a 10% increase in all-cause (hazard ratio [HR] = 1.10, 95% CI 1.003, 1.20) mortality. Patterns were similar for cardiovascular (HR = 1.17, 95% CI 0.98, 1.39) and cancer mortality (HR = 1.10, 95% CI 0.96, 1.25), not reaching statistical significance. The association with all-cause mortality was attenuated by 5% after adjustment for SES, 13% for health behaviours, 14% for cardiovascular risk factors, 5% for minor psychiatric morbidity, 29% for all variables. Repeating analyses with each item separately and excluding participants who died within five years of personality assessment did not change the results materially.
Conclusion
Low conscientiousness in midlife is a risk factor for all-cause mortality. This association is only partly explained by health behaviours, SES, cardiovascular disease risk factors and minor psychiatric morbidity in midlife.