The impact of "non-evaluative" and "evaluative" friends on cardiovascular reactivity during a stressful math task

This study was conducted to further examine the role of social support in moderating cardiovascular reactivity to behavioral stress. Specifically, evaluation potential was manipulated in order to determine if absence of evaluation is a critical ingredient for the beneficial effects of support on cardiovascular reactivity. Forty-eight female university students performed a stressful math task while alone or in the presence of a close female friend. The friend condition was designed to be either high or low in evaluation potential. This was achieved by manipulating whether the friend could view the subject’s questions and answers to the math task. Findings indicate that subjects who were assigned to the “non-evaluative” friend condition showed a trend for reduced systolic blood pressure reactivity compared to subjects who were alone during the task. Significant differences only emerged during the last minute of the task. Subjects in the “evaluative” friend condition did not show differences from the other groups on any cardiovascular measure, thereby suggesting that a social support manipulation can fail if evaluative situational elements are not carefully controlled for. The validity of the evaluation vs. non-evaluation distinction was supported by the observation that the friends’ cardiovascular activity level during the task showed significant differences in systolic and diastolic blood pressure. Specifically, the “non-evaluative” friends showed habituation on these measures during the task, whereas the “evaluative” friends did not habituate, remaining at pre-task levels of response.