Previous research on the construct and measurement of Masculine Gender Role Stress (MGRS) validates the assumption of sex differences in the appraisal of stressful situations. The present study was designed to extend the validity of the construct, MGRS, by examining its association with a set of physiological responses known as cardiovascular reactivity. Generally, such reactivity is measured in terms of systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR). Cardiovascular hyper-reactivity has been implicated as the major pathogenic mechanism through which psychological variables such as Type-A behavior and hostility may increase one's risk of coronary heart disease. A major underlying assumption of the dissertation is that the same gender-role socialization which leads to MGRS may also underlie development of Type-A behavior and hostility, and most importantly, cardiovascular hyper-reactivity. Forty-eight male undergraduate students volunteered to complete questionnaires measuring MGRS, Type-A behavior, and hostility, and participated in a one-hour laboratory session in which cardiovascular reactivity was assessed. Measures of SBP, DBP, and HR were obtained during consecutive phases of the assessment: (1) relaxation baseline, (2) the first stressor, (3) relaxation baseline, (4) the second stressor. All subjects were exposed to both stressors, a Cold Pressor Task (CPT) and a structured Masculine Threat Interview (MTI) in counter-balanced order. Subjects were divided into equal groups representing lower, middle, and upper thirds of MGRS. Results indicated that MGRS scores were significantly related to cardiovascular reactivity, specifically the SBP response. Thus, higher levels of MGRS were associated with proportionate increases in SBP reactivity. Within-subjects comparisons demonstrated no difference between stressors, the CPT versus the MTI, for SBP reactivity. Regression analyses indicated that MGRS scores were a better predictor of SBP reactivity than either Type-A behavior or hostility. Together, all three psychological variables accounted for 20% of the variance of systolic reactivity; however MGRS alone accounted for 17% of that variance. These findings add considerable support to the theoretical assumption that gender role socialization plays an important role in men's appraisal of psychological stress, and that such stress has measurable (harmful) effects on cardiovascular physiology. / Ph. D.