Familial resemblance for hostility: The National Heart, Lung, and Blood Institute Family Heart Study

Objective: The purpose of this study was to examine whether several aspects of hostility as measured by the Cook-Medley Hostility Scale (ie, aggressiv e responding, hostile affect, cynicism, and overall hostility score) were d etermined in part by family factors (ie, genes and/of familial environments ). Methods: Analyses were based on 680 European-American families (2525 ind ividuals) from the NHLBI Family Heart Study (FHS), a population-based study of genetic and nongenetic determinants of CHD, atherosclerosis, and cardio vascular risk factors. The influence of family relationships, age, and educ ation on the variation in each of the four hostility scores were estimated. Results: Significant familial resemblance in all hostility scores was foun d, accounting for 42% of the variance in total hostility, 30% in cynicism, 38% in aggressive responding, and 18% in hostile affect. Very little of thi s resemblance could be explained by similarities in education. Familial res emblance for cynicism was solely due to significant parent-offspring and si bling correlations (ie, no spouse resemblance), suggesting the possibility of genetic influences. Gender and generation differences were also evident in the familial correlations. Conclusions: Hostility aggregates in families . Both family environmental and genetic sources of resemblance are suggeste d for hostility.