In recent years, several lines of research in social psychology have been brought together under the common label of Attribution Theory, i.e., how an individual ascribes a cause to an effect. The understanding of such causal explanations aids in the prediction of behavioral and emotional reactions of people to life events. In terms of attribution theory, the individual who experiences illness and who experiences success or failure in attempts to cope with that illness must ascribe these events to some cause. A person's illness and his perceived success (or failure) in coping with his illness is conceptualized as the effect to be explained, and the cause formulated by the individual to explain his illness or its outcomes is conceptualized as the attribution. A Myocardial Infarction presents the patient with a sudden, critical life event. Academic achievement oriented and some clinical studies suggest that future expectations about success or failure, and affective reactions may be attributionally based. If these results generalize to the situation of Myocardial Infarction, the causal attributions will mediate responses to the illness. The objectives of this inquiry are to examine the causal attributions of Myocardial Infarction patients in relation to their success or failure in coping with the illness, their affect, their expectancies for future success or failure, and the success or failure coping as perceived by the provider. The sample of 200 patients admitted to the Hospital of the University of Penna. will complete an affect scale and an attributions interview. Subjects and their physician or nurse will also estimate success or failure in coping with their illness. Analyses will include appropriate analyses of variance and discriminate analyses. Possible benefits of the study include: greater understanding of the cognitive and affective responses to the situation of Myocardial Infarction; greater understanding of the relationship between such responses and patients' expectations about coping with their illness; greater capability of nurses and other health care professionals to predict reactions of patients to their Myocardial Infarction situation; specific data from which intervention programs to alter coping behaviors might be developed.