Over 50 epidemiologic, clinical, and experimental studies of behavioral influences on atherosclerosis and CHD have been reviewed; of these investigations, no more than five were published prior to 1975. Despite some inconsistencies and occasional conceptual and methodologic problems in the studies comprising this relatively young literature, the preponderance of available evidence indicates that psychosocial variables play a significant role in coronary disease. To summarize briefly, the Type A behavior pattern has been found predictive of new CHD in nearly all prospective studies of initially healthy individuals, and therapeutic modification of Type A has been shown to reduce risk of recurrent nonfatal MI. Among most prospective studies of post-MI patients and of persons at heightened risk for CHD due to elevations in traditional risk factors, however, Type A has not been found to predict, respectively, recurrence of MI or initial clinical events. Additionally, Type A individuals have shown more extensive coronary artery atherosclerosis on angiographic examination than Type Bs in a minority of studies, and, generally, only where Type A behavior has been measured by the SI. It is noted that many of these clinical studies may be faulted, though, for their use of small and heterogeneous patient samples and for possible biases in the selection and recruitment of subjects. In contrast to the globally defined Type A pattern, a high potential for hostility and an inability or unwillingness to express anger (anger-in) have emerged as significant predictors or correlates of coronary disease in all epidemiologic and clinical studies in which these variables have been examined. These consistent results suggest that a predisposition to hostility and anger, and the inhibited expression of such feelings, represent a "toxic" component of the Type A pattern. Several recent prospective investigations indicate also that high levels of life stress and possession of poor or inadequate social resources are predictive of CHD. The concepts of life stress, social network, and social support, as well as relationships among these variables, are not well-understood, however, and much additional work is needed to identify specific pathogenic and protective attributes of the social environment. In addition to studies of the psychosocial antecedents of CHD in human beings, there now are several published studies of behavioral influences on the development of coronary lesions in animal models.(ABSTRACT TRUNCATED AT 400 WORDS)