Investigators at the University of Miami evaluated cardiovascular and hormonal functions at rest and after standardized manipulations designed to evoke autonomic nervous system arousal. Two hundred and fifty-six subjects were enrolled into a 2 (male, female) x 2 (Black, white) x 2 (25-44 years, 55-64 years) x 2 (Miami, Durham) design. Subjects were compared across a broad range of socioeconomic status. Each subject was scheduled for three laboratory sessions. Sessions 1 and 2 were two weeks apart. Session 3 was six months later. During the sessions, individuals were subjected to a forehead cold pressor stimulus, a video game, and an evaluative speech stressor. Noninvasive cardiovascular measures assessed included heart rate, cardiac output, peripheral resistance, Heather Index, pre-ejection period, left ventricular ejection period, and diastolic, systolic, and mean arterial blood pressure. On the same day as the laboratory session, subjects wore an ambulatory impedance and electrocardiogram monitor at work and at home. The following day subjects wore an ambulatory blood pressure monitor at work and at home. Data were analyzed in terms of stability of baseline values, differences in laboratory reactivity between groups, differences in reactivity between tasks, reliability of responses to tasks across sessions, differences in reactivity as an individual difference variable, and generalizability of reactivity in the laboratory to cardiovascular function observed in more naturalistic settings. Improved procedures were developed for monitoring impedance cardiographic and electrocardiographic activity.