There were four studies. Study 1 in the first two years measured hemodynamics in 200 subjects to test the hypothesis that hostile distrust was associated with increased total peripheral resistance (TPR) response to social challenge, and that adolescents exhibiting this response pattern had elevated levels of ambulatory BP, fasting insulin, glucose, blood lipids, and central obesity. Study 2 followed 200 subjects for four years to determine if defensive hostility and distrust were related to tracking at higher levels of BP (measured every 6 months), and insulin/ glucose/ cholesterol (measured once per year). Study 3 in years 3 and 4 evaluated the influence of race on the cross-situational consistency of hostile distrust/BP by measuring the latter responses in 200 adolescents during structured encounters with a friend of the same race and sex, an unfamiliar same-race peer, and an unfamiliar other-race peer (black or white). Study 4 evaluated video and audiotape recordings from Studies 1 and 3 to test the hypothesis that distrustful individuals expressed more hostile affect in encounters with others, elicited more negative treatment, were perceived as hostile regardless of observer race or gender, and thus experienced chronic, health-damaging interpersonal stress. Study 4 data were used to examine the possibility that hostile distrust is related to exposure to crime, poverty, and racial discrimination.