research suggested. Several investigators reported low or nonexistent relation-
ships between Type A behavior and coronary disease (Matthews & Haynes,1986; Siegman, 1994). How can we interpret these findings? It seems unlikely
that Type A behavior once caused heart disease but that suddenly it did not.
It also does not seem likely that all the earlier studies somehow identified a
relationship where one did not exist.
Researchers found the answer to this puzzle by breaking Type A into its
components. As you may recall, Type A is actually a collection of several behav-ior tendencies that tend to go together. In essence, when we measure Type A,
we are measuring more than one trait. It is possible that only one or two of
these components are responsible for health problems. In that case, we wouldexpect to find only weak and sometimes nonsignificant associations between
Type A and cardiovascular disease. This line of reasoning led some researchers
to look for the “toxic component ”of Type A behavior.
What did they find? A large amount of evidence now points to the hostil-
itycomponent as the culprit (Bunde & Suls, 2006; Krantz & McCeney,
2002; Smith, 2006; Smith, Glazer, Ruiz, & Gallo, 2004). People high in hos-
tility aren ’t necessarily violent or even bossy. Rather, they tend to have a
strong reaction to the daily frustrations and inconveniences we all experience.
They respond to even minor annoyances with “expressions of antagonism,
disagreeableness, rudeness, surliness, criticalness, and uncooperativeness ”
(Dembroski & Costa, 1987). People high in hostility might become upsetwhen stuck in a slow-moving line at the post office or when they misplace
something and can ’t find it right away. Most of us have learned to take these
minor inconveniences in stride, but some people become highly irritated. We
sometimes refer to these people as “quick-tempered ”because it usually
doesn ’t take much to send them into a fit of anger. It should be noted that re-
searchers sometimes use the terms anger oraggression to refer to this trait
(Smith et al., 2004). However, for clarity ’s sake, I will simply use the term
hostility here.
Several investigations find that scores on hostility and anger measures do
a good job of predicting coronary artery disease (Kawachi, Sparrow, Spiro,
Vokonas, & Weiss, 1996; Niaura, Todaro, Stroud, Spiro, Ward, & Weiss,
2002; Williams, Nieto, Sanford, Couper, & Tyroler, 2002; Williams, Nieto,
Sanford, & Tyroler, 2001). One investigation followed 12,986 healthymiddle-aged men and women over a 4 1/2-year period (Williams et al.,
2000). Compared to participants low in trait anger, participants who scored
high on this trait were more than twice as likely to suffer some form of coro-nary heart disease during this time. More alarming, the high-anger partici-
pants were nearly 3 times as likely to be hospitalized or die from heart
disease during the study.
Why is hostility related to cardiovascular problems? Researchers have iden-
tified several possible connections, including unhealthy lifestyles (Siegler, 1994),poor social support (Smith, Fernengel, Holcroft, Gerald, & Marien, 1994),immune system weaknesses (Uchino, Caccioppo, & Kiecolt-Glaser, 1996), and
blood lipid levels (Richards, Hof, & Alvarenga, 2000). Other studies find that
people high in hostility frequently exhibit the kind of physiological reactions196 CHAPTER 8 The Trait Approach