Beginning in 1980, the longitudinal study examined the Type A behavior pattern, hostility, physiological responses and family interactive behaviors in primarily white, upper-middle class children and parents. The study was renewed several times. In the fiscal year 1992 renewal, the research was extended to include the study of Black children and those from lower-middle to middle class families. The inclusion of these groups is important not only because these they have been understudied, but also because an examination is needed of developmental factors that may be important in accounting for the much higher incidence of hypertension and related disorders in Blacks and in lower and lower-middle class groups. The current study examines the patterns of cardiovascular responses exhibited by Black and white children in order to better assess hemodynamic and autonomic nervous system mechanisms that underlie these responses. It also examines how these hemodynamic patterns relate to cardiovascular risk factors such as body fat distribution, left ventricular geometry (via echocardiography), as well as insulin, glucose, and lipid levels and it explores a new conceptualization of hostility indices and cardiovascular risk factors.