A regression-based meta-analysis examined the degree to which the effects of a family history of hypertension on cardiovascular reactivity are moderated by the magnitude of cardiovascular responses elicited in challenge/task conditions. Mean change scores for negative family history groups were regressed on mean change scores for positive family history groups. The slopes of separate regression lines obtained for systolic and diastolic blood pressure and heart rate were significantly less than 1.0 and the y-intercepts for these regression lines were significantly greater than zero. This pattern indicates that family history differences in cardiovascular reactivity to stress are greatest in situations that elicit the smallest baseline-stressor change scores in non-family-history groups.