 37. Personality and Health 779
firmed in the Hawaii Personality and Health 
Cohort, a prospective study across more 
than 40 years. At midlife, men and women 
who as boys and girls were assessed by their 
teachers as more conscientious had better 
self-rated health, smoked less or not at all, 
and the women (but not the men) had lower 
BMI. The effect of childhood conscientious -
ness on self-rated health was found to be 
mediated by smoking and BMI (Hamp -
son, Goldberg, Vogt, & Dubanoski, 2006). 
Childhood conscientiousness also contribut -
ed to educational attainment, which in turn 
influenced health behaviors and clinical 
health status, confirming the wide-  reaching 
effects of conscientiousness on life outcomes 
(Hampson, Edmonds, Goldberg, Dubano -
ski, & Hillier, 2015). Although there is a 
tendency to be skeptical of relationships un -
covered in any particular longitudinal sam -
ple, much follow-  up research confirms the 
validity of the robust findings that emerged 
in these lifespan studies. The relevance of 
conscientiousness to health has been con -
firmed in meta-  analyses of both cross- 
sectional and longitudinal studies, as well as 
in a nationally representative samples, dem -
onstrating that low conscientiousness is re -
lated to low activity levels, excessive alcohol 
use, drug use, unhealthy eating, risky driv -
ing, risky sex, suicide, tobacco use, violence, 
impaired biomarkers, illness, likelihood of 
physical limitations, and premature mortal -
ity (Bogg & Roberts, 2004; Chapman, Fis -
cella, Kawachi, & Duberstein, 2009; Fried -
man & Kern, 2014; Goodwin & Friedman, 
2006; Hagger-  Johnson et al., 2012; Kern 
& Friedman, 2008; Turiano et al., 2015). 
Why should conscientiousness be such a ro -
bust predictor? It is likely that it is relevant 
to the full range of ongoing biopsychosocial 
processes described earlier in the sophisti -
cated models of personality and health. The 
prospective association of conscientiousness 
with a variety of health behaviors and pat -
terns, and with longevity, suggests that a 
child with a higher level of conscientious -
ness initiates and elicits a healthy life-  course 
pathway, revealing what it means to thrive 
and flourish (Friedman, Tucker, Schwartz, 
Martin, et al., 1995; Kern et al., 2014).
What about the relative benefits of higher 
sustained levels of conscientiousness over 
the lifespan versus higher levels only in 
adulthood? Conscientiousness, measured independently in childhood and adulthood, 
predicts health mortality risk across the 
full lifespan, and the link from childhood 
remains when adult conscientiousness and 
certain behavioral variables are controlled 
(Martin, Friedman, & Schwartz, 2007; 
Hampson et al., 2015). The lowest mortality 
risk is for those with high conscientiousness 
at both time points.
The beneficial effects of conscientiousness 
on longevity have now also been document -
ed prospectively in adulthood. In the Edin -
burgh Artery Study (a prospective study of 
a community sample of men and women), 
men who were low in conscientiousness 
were more likely to die from any cause over 
a 7-year follow-  up (Whiteman, 2006). In a 
17-year follow-  up in the Whitehall study, 
low conscientiousness in midlife was a key 
risk factor for all-cause mortality, partly ex -
plained by behavior, SES, and certain other 
risks (Hagger-  Johnson et al., 2012). Studies 
of disease progression with patient samples 
also demonstrate the protective effects of 
being more conscientiousness. For exam -
ple, renal patients low on conscientiousness 
were more likely to have died 4 years later 
(as were those high on neuroticism), after 
researchers controlled for age and diabetic 
status (Christensen et al., 2002). A number 
of studies confirm ties between conscien -
tiousness and a range of health-  enhancing 
behaviors among adult patient and nonpa -
tient groups (Bogg & Roberts, 2004). For 
example, women with breast problems who 
were more conscientious were more likely to 
undergo mammography 2 years later, even 
when the effects of eight other predictors of 
mammography were controlled (Siegler, Fea -
ganes, & Rimer, 1995). Adults tend to gain 
weight at midlife, and a study of over 3,000 
participants in the North Carolina Alumni 
Heart Study showed that midlife weight 
gain measured at four time points over 14 
years was larger among men and women 
who were less conscientious, implying poor -
er eating and exercise habits (Brummett 
et al., 2006). Many of these studies partly 
support health–  behavior models by demon -
strating that more conscientious adults have 
healthier lifestyles and are more adherent 
to disease treatment and self-  management 
(Molloy, O’Carroll, & Ferguson, 2014), but 
the studies do not rule out additional under -
lying biological contributions to both health 