Paradoxical effects of social support on blood pressure reactivity among defensive individuals

Social support can reduce cardiovascular responses to an acute stressor. However, prior clinical research suggests that defensive individuals may react negatively to social support.

This experiment examined whether emotional support provided during a speech stressor would escalate rather than decrease blood pressure (BP) reactivity among defensive individuals.

After completing personality measures, 176 female undergraduates were randomly assigned to give a speech in 1 of 3 social conditions: alone, or with a neutral or supportive confederate present. Mean arterial BP was assessed at baseline, immediately before, and during and after the stressor.

In the supportive condition, defensiveness predicted higher BP reactivity during anticipation (beta = .35, p = .04) and delivery of the speech (beta = .32, p = .03), and longer recovery to baseline BP levels (beta = .35, p = .01). In the absence of support (i.e., alone and neutral conditions), defensiveness was not associated with BP reactivity. Defensiveness also predicted greater dissociation between subjective stress and BP responses (beta = .35, p = .05), but only in the supportive condition.

According to results, the provision of social support during stressors does not benefit defensive individuals' BP reactivity but has the opposite effect.