This experiment tested three hypotheses linking the right cerebral regulation of hostility and physiological arousal. First, replication of previous research supporting heightened physiological (systolic blood pressure, diastolic blood pressure, and heart rate) reactivity among high hostile subjects was attempted. Second, a positive association between hostility and reactivity of facial valence and intensity to stress were expected. Last, hemispheric lateralization of cerebral activity in response to stress was measured. Low- and high-hostile subjects were identified using the Cook Medley Hostility Scale (CMHS). All subjects completed the cold pressor paradigm and were videotaped before, during, and after the stressor for analysis of facial valence and intensity. Physiological measures (SBP, DBP, and HR) were recorded and dichotic listening procedures were administered before and after the stressor. The primary finding of this research was greater right cerebral activation to stress among high-hostile subjects, as indicated by their enhanced intention to the left ear. Data further supported previous findings of heightened physiological reactivity to stress among high-hostiles. However, no hostility group differences on facial expression measures were found. Data suggest a positive relationship between right cerebral activity and cardiovascular arousal. / Master of Science