Personality as Risk and Resilience in Physical Health

Research on the association between personality characteristics and subsequent physical health has produced several consistent findings and identified other tentative relationships. Chronic anger/hostility and neuroticism/negative affectivity are the best established personality risk factors for poor health. Optimism, social dominance, and other traits also appear to influence risk. Several mechanisms have been identified as possibly underlying these effects, but few have been evaluated definitively. Future research may be well served by incorporation of concepts and methods from current personality research. KEYWORDS—personality and health; psychosomatics; stress The fascinating notion that personality influences physical health lies at the heart of several fields. Thirty years ago this hypothesis was central in the emergence of health psychology and behavioral medicine, as it was previously for psychosomatic medicine. Studies in which personality traits predicted health outcomes such as longevity and the onset of serious illness also contributed to the resurgence of personality research in recent decades, as those studies addressed the criticism that personality variables have limited predictive utility. Suggestions that personality influences disease appear over centuries of medical writing (Smith & Gallo, 2001). Yet, the view that connections between ‘‘mind and body’’ are more fiction than fact is prominent in the recent history of medicine, as when an editor of the New England Journal of Medicine described the hypothesis that personality and related psychological factors influence the development of medical disease as ‘‘folklore’’ (Angell, 1985). A growing body of research has challenged such skepticism. Yet, methodological and conceptual issues often limit the kinds of conclusions that can be drawn, thus creating an agenda for future research. TRAITS LINKED TO HEALTH Dozens of purportedly distinct personality characteristics have been studied as influences on health. The following review summarizes the most compelling evidence. Beyond Type A: Hostility and Dominance The groundbreaking work of M. Friedman and Rosenman (1959) on Type A behavior and coronary heart disease (CHD) is perhaps the most well-known example of the personality–health hypothesis. Two decades of research following their description of the Type A behavior pattern (i.e., competitiveness, achievement striving, impatience, hostility, excessive job involvement, and emphatic speech) generally supported its role as a risk factor. Several failures to replicate later challenged this conclusion, even though the literature as a whole demonstrated an association. The failures to replicate led researchers to examine individual elements within the multifaceted Type A construct, as inconsistent associations between the pattern and CHD might indicate that only some components influenced health. Hostility soon emerged as the most unhealthy Type A characteristic. Although negative findings have also appeared in this literature, many subsequent studies have supported an association of individual differences in the tendency to experience anger, cynical or suspicious beliefs, and antagonistic interpersonal behavior with asymptomatic atherosclerosis, the incidence of CHD, and mortality from cardiovascular and other causes (Smith, Glazer, Ruiz, & Gallo, 2004). Other studies indicate another unhealthy aspect of the Type A pattern. A socially dominant style including loud, rapid, and emphatic speech and a tendency to ‘‘cut off’’ and ‘‘talk over’’ others during social interaction is associated with CHD risk (Houston, Chesney, Black, Cates, & Hecker, 1992). Other prospective studies have supported an association between dominance and subsequent health (cf. Smith, Gallo, & Ruiz, 2003), as do the results of nonhuman primate models of atherosclerosis (Kaplan & Manuck, 1998). Negative Affectivity, Neuroticism, and Risk Individual differences in the experience of negative emotions (e.g., anxiety, sadness) have long been suspected as contributing Address correspondence to Timothy W. Smith, Department of Psychology, University of Utah, 390 South 1530 East (room 502), Salt Lake City, UT 84112; e-mail: [email protected]. CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE Volume 15—Number 5 227 Copyright r 2006 Association for Psychological Science to poor health. This trait is represented in major personality taxonomies, commonly labeled neuroticism or negative affectivity. An early and influential review concluded that this broad dimension conferred vulnerability to disease (H.S. Friedman & Booth-Kewley, 1987). However, critical responses to the review’s conclusions suggested that this effect may have been overestimated through the inclusion of studies relying on health-outcome measures that combined illness behavior (e.g., somatic complaints) and actual illness (e.g., diagnosed diseases or mortality). As a result, the apparent association between neuroticism and subsequent disease might have reflected—at least in part—an association between this trait and somatic complaints rather than objectively defined disease. However, subsequent well-designed prospective studies have consistently supported the prior conclusion (Suls & Bunde, 2005); neuroticism and negative affectivity are associated with reduced longevity and increased incidence of objectively diagnosed serious illness. Personality as Resilience: Optimism and Conscientiousness The tendency to hold optimistic—as opposed to pessimistic or even hopeless—beliefs about the future has been found to be associated with better health in several prospective studies. These effects include lower incidence of CHD (Kubzanky, Sparrow, Vokonas, & Kawachi, 2001), better prognosis following heart surgery (Scheier et al., 1999), and greater longevity (Giltay, Kamphuis, Kalmijin, Zitman, & Kromhout, 2006). Previous research has suggested that some of the apparent association between optimism and health could actually involve shared variance with neuroticism and the related tendency toward excessive somatic complaints. However, recent studies support a prospective association with objective health outcomes. In some studies these effects have been independent of measures of negative affectivity or neuroticism, although in others it is unclear if the possible overlap between these traits and optimism could contribute to observed associations with objective health outcomes. Conscientiousness has been found to predict longevity, even when this trait is measured during childhood (H.S. Friedman et al., 1995). Among patients with chronic medical illness, conscientiousness is associated with longer survival (Christensen et al., 2002).