 37. Personality and Health 783
supported empirically, although risk-  taking 
may be a factor; cheerfulness may be a com -
plex blend of traits associated with both 
health costs and benefits (Martin et al., 
2002). For example, sensation seeking can 
accompany extraverted disinhibition (Depue 
& Collins, 1999), described by Zuckerman 
(1994) as impulsive unsocialized sensation 
seeking. Outgoing and sociable children and 
adults are more likely to enjoy not only the 
benefits of friendship and popularity but 
also the costs associated with peer-  initiated 
problem behaviors. For example, extravert -
ed sociability predicts smoking and drink -
ing. In the Hawaii study and the Terman 
study, children who were assessed as more 
extraverted reported drinking more alco -
hol at midlife (Hampson, Goldberg, et al., 
2006; Tucker et al., 1995).
It has been hypothesized that to the ex -
tent that adults tend to experience positive 
emotions, they will not be exposed to the 
accumulation of adverse physiological stress 
reactions, and hence should be more likely 
to have long, healthy lives. Some evidence 
to support this assertion was found in a 
prospective study of 185 Catholic nuns, in 
which Danner, Snowdon, and Friesen (2001) 
reported an association between positive 
emotional content of written autobiogra -
phies at age 22 and longevity six decades 
later, after controlling for age and educa -
tion. Whether emotional expression in these 
autobiographies reflected a coping style in 
response to stress, a pervasive disposition to 
experience more positive emotion, an abil -
ity to resolve negative emotions, or indeed, 
some other mechanism could not be deter -
mined from these data, and various studies 
relating positive emotionality to mortality 
have not found it to be simply protective 
(e.g., Janoff-  Bulman & Marshall, 1982; 
see Friedman & Kern, 2014, for an analy -
sis of happiness, subjective well-being, and 
health). Causal links remain murky (Cohen 
& Pressman, 2006; Pressman & Cohen, 
2005; see also Cohen et al., 2003; Hud -
son, Lucas, & Donnellan, 2019). Postulated 
mechanisms include health practices, physi -
ological responses, and a stress-  buffering 
effect in which positive affect modulates 
the stress response (Pressman & Cohen, 
2005), but it is probably the case that sense 
of meaning, optimism, and persistence are generally much more relevant to causal path -
ways than is positive affect. For example, in 
one community study, dispositional opti -
mism was associated with prudent health 
behavior  (i.e., less smoking and alcohol use, 
and more physical activity; Steptoe, Wright, 
Kunz-  Ebrecht, & Iliffe, 2006). It is impor -
tant to avoid the popular misconception that 
positive affect directly causes good health or 
that optimism will mobilize the immune sys -
tem and cause tumors to shrink (Coyne & 
Tennen, 2010; Sloan, 2011).
Consistent with a focus on short-term mo -
tivation, optimists recover better from medi -
cal interventions than do pessimists. For 
example, patients who were more optimistic 
were less likely to be rehospitalized after cor -
onary artery bypass graft surgery (Scheier 
et al., 1999); more optimistic women dem -
onstrate better adjustment to breast cancer 
(Carver et al., 1993); and more optimistic 
patients with head and neck cancer had a 
greater chance of 1-year survival, when re -
searchers controlled for sociodemographic 
and clinical variables (Allison, Guichard, 
Fung, & Gilain, 2003). Women in the HWS 
who were more optimistic showed less pro -
gression of carotid artery disease than did 
those who were chronically pessimistic 
(Matthews, Räikkönen, Sutton-  Tyrrell, & 
Kuller, 2004). Overall, a diversity of evi -
dence supports the benefits of optimism in 
the short term (Boehm & Kubzansky, 2012; 
Scheier & Carver, 2003), likely because op -
timism captures motivation and persever -
ance. Again, however, because some mea -
sures of positive affect and optimism may 
reflect how a person feels, and self-  reports 
of health often capture affect, it is necessary 
to (1) institute a number of corrections, in -
cluding objective health outcomes (or using 
longevity as the outcome); (2) control for 
concurrent self-rated health; (3) control for 
conscientiousness; and (4) use a prospective 
design. More correlational studies of self- 
reported affect and self-  reported health (or 
minor health fluctuations or temporary bio -
marker changes) are not needed.
Intelligence
Intelligence, including intelligence in youth, 
is associated with health and longevity (Cal -