Previous research has identified trait hostility and social isolation as possible psychosocial risk factors for coronary heart disease (CHD). However, few studies have examined hostility and social support simultaneously to determine their independent and possible interactive relations with CHD and disease-promoting mechanisms. Hypotheses derived from a general interpersonal model were tested in a study examining trait hostility and perceived social support as predictors of cardiovascular reactivity to laboratory stressors. Healthy college students (53 men, 55 women) performed speech and mental arithmetic tasks while blood pressure and heart rate were monitored. There was an interactive effect of hostility and perceived social support on systolic and diastolic blood pressure (SBP and DBP) reactivity. Higher hostility scores were associated with greater SBP reactivity for participants who were high in perceived social support; whereas for those with low social support scores, greater hostility was associated with somewhat less SBP reactivity. The same pattern was obtained for DBP, but only during the speech task. These findings encourage further research conceptualizing trait hostility within a general interpersonal framework that calls attention to both positive and negative person-environment transactions.
