Prevention of coronary heart disease (CHD) will be enhanced by controlling hypertension, reducing blood cholesterol, maintaining normal weight, increasing physical activity, reducing smoking, and having a healthy diet. Understanding how to achieve these important public health aims requires an understanding of the behavioral factors involved in prevention. Behavioral risk factors remain the single most preventable cause of human illness and suffering. The University of North Carolina Alumni Heart Study is ideally suited to explore the associations between and among these important behavioral risk factors, and to understand how personality, in particular individual differences in hostility and depression act to determine individuals' risk factor behaviors, and to answer important questions about the role of hostility and psychosocial factors in CHD risk during the middle years.