The aim of this research is to examine the mechanism through which social support affects morbidity and mortality from coronary heart disease. Two hypotheses have been proposed to account for this mechanism, both of which operate through effects on risk factors for coronary heart disease, specifically arterial blood pressure and serum lipids. the stress- buffering hypothesis states that social support functions as a social resource for individuals exposed to social stressors; those persons with more support are less vulnerable to the risk-enhancing effects of stressors. The health behavior hypothesis states that persons with more support engage in more positive health behaviors, such as avoiding tobacco; moderate alcohol use; exercise; and, a prudent diet. A major limitation in research to date to evaluate these alternative hypotheses has been the failure to conceptualize and measure social support in a way appropriate to detect its effects in varying social and cultural contexts. This is a major issue in research in sub-cultural communities that are also high risk communities, such as African-Americans. In this project a cross-sectional survey of social stressors, social supports, health behaviors, and arterial blood pressure and serum lipids will be conducted in a black community in the rural South to evaluate the relative strengths of the stress-buffering versus the health behavior hypothesis. Social support will be measured using a culturally appropriate technique which is sensitive both to the distinction between kin and nonkin social support, and the modification of the effects of that support by generational status. Multiple regression analysis and path analysis will be used to evaluate the alternative hypotheses. The research will contribute directly to a better understanding of the mechanism through which social support influences coronary heart disease.