Personality Traits as Risk Factors
for Physical Illness
Timothy W. Smith
Linda C. Gallo
University of Utah
The belief that stable patterns of thought, emotion, and behavior contribute to the development of physical illness has been present throughout the history of medicine (McMahon, 1976). Hippocrates, for example, argued that four basic temperaments or personality types reflected excesses of specific humors and caused corresponding medical disorders. Many centuries later, Sir William Osler (1892) suggested that coronary heart disease befell “not the neurotic, delicate person …but the robust, the vigorous in mind and body, the keen and ambitious man, the indicator of whose engine is always at full speed ahead” (p. 839). The descriptions of personality, disease, and the nature of their relation have varied widely, but the essence of this psychosomatic hypothesis has remained unchanged.
Earlier in this century, the hypothesis was refined by the psychoanalytic school in psychosomatic medicine (Alexander, 1950; Dunbar, 1943). These models assigned a pathophysiological role to unconscious personality dynamics, and suggested a correspondence between specific emotional conflicts and medical conditions. Unlike previous psychoanalytic formulations of hysteria or hypochondriasis (Freud, 1933), these models identified causes for actual disease, rather than unfounded physical symptoms. For example, an unconscious conflict between aggressive impulses and anxiety concerning the consequences of their expression was described as a cause of essential hypertension. Although a weak scientific foundation limited the impact of this approach on the mainstream of either medicine or psychology (Surwit, R. B. Williams, & Shapiro, 1982), it set the stage for current research on personality and illness.
During the same period, developments in the physiology of stress provided an essential, scientifically credible set of mechanisms connecting personality and disease (Ax, 1953; Cannon, 1939; Seyle, 1936, 1952; Wolff, 1950). Not surprisingly, the psychophysiology of stress and emotion remains an integral component of this research area (Contrada, Leventhal, & O'Leary, 1990). The immediate predecessor of the current interest in the issue is undoubtedly the seminal work of M. Friedman and Rosenman (1959) on the Type A coronary prone behavior pattern. Although M. Friedman and Rosenman actively avoided describing their work in the language of personality traits, their work is now recognized as involving personality characteristics (Suls & Rittenhouse, 1987). Friedman and Rosenman's version of the centuries- old psychosomatic hypothesis was a major force in the early development of the larger fields of behavioral medicine and health psychology (G. C. Stone, F. Cohen, & Adler, 1979; Weiss, Herd, & Fox, 1981).
An often overlooked forerunner to current research on personality traits as risk factors for illness are early studies that used psychometrically sound measures of personality in large, prospective designs (e.g., Ostfeld, Lebovits, Shekelle, & Paul, 1964). Effects of personality variables on subsequent disease were examined while attempting to control statistically the possible confounding medical or demographic variables. Studies of this type provided important evidence of the merit of