INTRODUCTION The construct of cardiovascular reactivity (CVR) occupies a central place in both the history and current state of behavioral medicine research. Early theories identified transitory, stressinduced increases in heart rate, blood pressure, and other parameters as pathophysiologic mechanisms through which negative emotions, stressful life circumstances, and maladaptive social relations caused cardiovascular disease (1,2). Since that time, well-developed models of the potential role of CVR in the development of essential hypertension (EH) and coronary heart disease (CHD) have been proposed (e.g. 3,4). A large body of research has accumulated (5,6), and the methodology for examining the issue continues to be refined (7,8). Although some studies have not supported the hypothesized role of CVR (9,10), a variety of recent studies are consistent with this general model (1 I). For example, CVR to laboratory stressors has been found to predict later EH (12). Also, in both crosssectional and prospective designs, CVR in response to laboratory stressors has been found to predict more severe atherosclerosis (13,14). Similarly, exaggerated CVR to mental stress has been found to be associated with coronary artery disease among asymptomatic persons at high familial risk of CHD (15). Among patients with CHD, those who display the most pronounced CVR in response to laboratory mental stressors also display the greatest amount of myocardial ischemia during daily activities (16). Finally, some evidence suggests that heightened CVR predicts recurrent cardiovascular morbidity among survivors of myocardial infarction (17). Thus, CVR has been found to have predicted associations with the development, manifestations, and course of cardiovascular disease (CVD). Social processes have long been recognized as potentially important influences on CVR (18,19). Yet, until recently, social factors have not been a major focus of research on the construct. A largely non-social psychophysiology of CVR has been accumulated during much of the recent history of research on the topic (20). Although this work produced important advances in our understanding of the nature and consequences of CVR (21), the construct was, for the most part, studied without explicit attention to the social determinants of cardiovascular response. The collection of papers in this special issue reflect the range of work currently underway on the social psychophysiology of CVR. They illustrate the promise, unique challenges, and products of recent