THINKING CRITICALLY Does Hostility Increase the Risk of Heart Disease
The Physiology and Psychology of Health and Illness 409 hypertension later in life (Kasagi, Akahoshi, & Shimaoki, 1995; Light et al., 1999; Matthews et al., 2004). As also mentioned earlier, these physical reactions to stressors—and the chances of suffering stress-related health problems—depend partly on personality, especially on how people tend to think about stressors and about life in general. For example, the trait of hostility—especially when accompanied by irritability and impatience— has been associated with the appearance of coronary heart disease (Bunde & Suls, 2006; Day & Jreige, 2002; Krantz & McCeney, 2002; Smith, 2003). Removed due to copyright permissions restrictions. T H I N K I N G C R I T I C A L LY ealth psychologists see hostility as characterized by suspiciousness, resentDoes Hostility Increase the ment, frequent anger, antagonism, and distrust of others (Helmers & Krantz, 1996; Risk of Heart Disease? Krantz & McCeney, 2002; Williams, 2001). The identiﬁcation of hostility as a risk factor for coronary heart disease and heart attack may be an important breakthrough in understanding these illnesses, which remain chief causes of death in the United States and most other Western nations. But is hostility as dangerous as health psychologists suspect? H For a time, researchers believed that anyone who displayed the pattern of aggressiveness, competitiveness, and nonstop work known as Type A behavior was at increased risk for heart disease (Friedman & Rosenman, 1974). More recent research shows, however, that the danger lies not in these characteristics alone but in hostility, which is seen in some, but not all, Type A people. YOU CAN’T FIRE ME—I QUIT! ■ What am I being asked to believe or accept? Many researchers claim that individuals who display hostility increase their risk for coronary heart disease and heart attack (e.g., Bleil et al., 2004; Boyle et al., 2004). This risk, they say, is independent of other risk factors such as heredity, diet, smoking, and drinking. ■ Is there evidence available to support the claim? There is evidence that hostility and heart disease are related, but scientists are still not sure about what causes the relationship. Some suggest that the risk of coronary heart disease and heart attack is elevated in hostile people because these people tend to be unusually reactive to stressors, especially when challenged. During interpersonal conﬂicts, for example, people predisposed to hostile behavior display not only overt hostility but also unusually large increases in blood pressure, heart rate, and other aspects of autonomic reactivity (Brondolo et al., 2003; Suls & Wan, 1993). In addition, it takes hostile individuals longer than normal to get back to their resting levels of autonomic functioning (Gerin et al., 2006). Like a driver who damages a car’s engine by pressing the accelerator and applying the brakes at the same time, these “hot reactors” may create excessive wear and tear on the arteries of the heart as their increased heart rate forces blood through tightened vessels. Increased sympathetic nervous system activation not only puts stress on the coronary arteries but also leads to surges of stressrelated hormones from the adrenal glands. High levels of these hormones are associated with increases in cholesterol and other fatty substances that are deposited in arteries and contribute to coronary heart disease (Bierhaus et al., 2003; Stoney & Hughes, 1999; Stoney, Bausserman, et al., 1999; Stoney, Niaura, et al., 1999). Cholesterol levels do appear to be elevated in the blood of hostile people (Dujovne & Houston, 1991; Engebretson & Stoney, 1995). Hostility may affect heart disease risk less directly, as well, through its impact on social support. Some evidence suggests that hostile people get fewer beneﬁts from their social support networks (Lepore, 1995). Failing to use this support—and possibly offending potential supporters in the process—may intensify the impact of stressful 410 Chapter 10 Health, Stress, and Coping events on hostile people. The result may be increased anger, antagonism, and, ultimately, additional stress on the cardiovascular system. ■ Can that evidence be interpreted another way? Studies suggesting that hostility causes coronary heart disease are not true experiments. Researchers cannot manipulate the independent variable by creating hostility in randomly selected people in order to assess its effects on heart health. Accordingly, we have to consider other possible explanations of the observed relationship between hostility and heart disease. For example, some researchers suggest that higher rates of heart problems among hostile people are not due entirely to the impact of hostility on blood pressure, heart rate, and hormone surges. It may also be that a genetically determined tendency toward autonomic reactivity increases the likelihood of both hostility and heart disease (Cacioppo et al., 1998; Krantz et al., 1988). If this is the case, then the fact that hostility and coronary heart disease often appear in the same people might reﬂect not just the effects of hostility but also a third factor—autonomic reactivity—that contributes to both of them. It has also been suggested that hostility may be only one of many traits linked to heart disease. Depressiveness, hopelessness, pessimism, anger, and anxiety may be involved, too (Frasure-Smith & Lespérance, 2005; Kubzansky, Davidson, & Rozanski, 2005; Nicholson, Fuhrer, & Marmot, 2005; Suls & Bunde, 2005). ■ What evidence would help to evaluate the alternatives? Research on the role these other traits may play in heart disease will be vital, and that work is now under way. One way to test whether hostile people’s higher rates of heart disease are related speciﬁcally to their hostility or to a more general tendency toward intense physiological arousal is to examine how these individuals react to stress when they are not angry. Some researchers have done this by observing the physiological reactions of hostile people during the stress of surgery. One study found that even under general anesthesia, such people show unusually strong autonomic reactivity (Krantz & Durel, 1983). Because these patients were not conscious, it appears that oversensitivity to stressors, not hostile thinking, caused their exaggerated stress responses. This possibility is supported by research showing that, compared with other people, individuals who have strong blood pressure responses to stressors also show different patterns of brain activity during stress (Gianaros et al., 2005). ■ What conclusions are most reasonable? Most studies continue to ﬁnd that hostile individuals are at greater risk for heart disease and heart attacks than other people (Krantz & McCeney, 2002; Stansfeld & Marmot, 2002). But the relationship between hostility and heart disease is probably more complex than any current theory suggests; it appears that many factors underlie this relationship. A more elaborate psychobiological model may be required—one that takes into account that (1) some individuals may be biologically predisposed to react to stress with hostility and increased cardiovascular activity, each of which can contribute to heart disease; (2) hostile people help to create and maintain stressors through aggressive thoughts and actions, which can provoke others to be aggressive; and (3) hostile people are more likely than others to smoke, drink to excess, overeat, fail to exercise, and engage in other heart-damaging behaviors. We must also keep in mind that the relationship between heart problems and hostility may not be universal. Although this relationship appears to hold for women, as well as men, and for individuals in various ethnic groups (e.g., Davidson, Hall, & MacGregor, 1996; Nakano & Kitamura, 2001; Olson et al., 2005; Powch & Houston, 1996; Yoshimasu et al., 2002), ﬁnal conclusions must await further research that examines the relationship between hostility and heart disease in other cultures.