coping strategies (O’Brien and Delongis, 1996; see Chapter 5). In addition, conscien -
tiousness is associated with a propensity to follow socially prescribed norms for impulse
control (John and Srivastava, 1999; Bogg and Roberts, 2004, 2013). Recently,
measures of conscientiousness with good levels of reliability and validity have become
available. For example, the International Personality Item Pool contains statements such
as ‘am always prepared’ and ‘am exacting in my work’ in order to tap conscientiousness.
Those high in conscientiousness are more likely to consider these statements as
accurate self-descriptions. A growing body of research shows conscientiousness to be
positively associated with health-promoting behaviour patterns, health outcomes
and even longevity prompting much recent research into the relationships between
conscientiousness and health.
The key evidence for an effect of conscientiousness on longevity comes from the
Terman Life-Cycle personality cohort study. In this highly regarded study, a sample
of over 1,000 children born around 1910 completed various measures every 5 to 10
years from the age of 11. The original sample of children selected had above average
IQ and were drawn from the area around the Californian cities of San Francisco and
Los Angeles. The personality assessments included measures of conscientiousness,
optimism, self-esteem, sociability, stability of mood and energy level. Friedman et al.
(1993) reported that of these variables only conscientiousness was significantly
associated with lower mortality over time. The degree of association was such that
those high in conscientiousness were more likely to live longer (by about 2 years)
compared to those low in conscientiousness. Comparing the top and bottom 25 per
cent (quartiles) on conscientiousness indicated that those in the bottom quartile were
one and a half times more likely to die in any one year compared to those in the top
quartile. Figure 6.3 shows the survival curves for participants in the Terman sample
separately for males and females and for those with and without divorced parents among
those with high and low levels of conscientiousness. Hampson et al.(2013) using a
different cohort showed that childhood conscientiousness predicted objectively
measured health when members of the cohort were in their fifties. Those with lower
childhood conscientiousness were observed to have higher levels of obesity and worse
blood lipids. Reviews have shown low conscientiousness to be a consistent risk factor
for developing obesity across populations (Jokela et al., 2013a). Most recently, in the
largest study of its kind, conscientiousness has been shown to be the only higher-order
personality trait to be related to mortality risk across populations (Jokela et al., 2013b;
see also Kern and Friedman, 2008).
An important mechanism by which conscientiousness may influence health is
through health behaviour patterns. Friedman et al. (1995) showed that the impact of
conscientiousness on longevity in the Terman sample was partly accounted for by its
effect on smoking and alcohol use, that is, conscientious children were less likely to
become heavy smokers and drinkers. Consistent with these findings, Booth-Kewley
and Vickers (1994) found that conscientiousness was more strongly correlated with
clusters of health-related behaviours than the other Big Five traits and was particularly
strongly associated with health protection and accident control behaviours. Similarly,
Courneya and Hellsten (1998) reported that, of the Big Five traits, conscientiousness
was most strongly related to engaging in exercise behaviours, while Siegler, Feaganes
and Rimer (1995) showed that regular mammography attendance was predicted by
conscientiousness and extraversion. A comprehensive meta-analysis of work on the
PERSONALITY AND HEALTH 129