An investigation into the effects of social evaluation on cardiovascular and endocrine responses to the CO2 stress test in humans

The present study examined whether social evaluation could heighten individuals' physiological responses to the CO2 stress test, and the hypothalamic-pituitary-adrenal (HPA) response in particular. Twenty-five healthy volunteers undertook the CO2 test under three conditions: (i) standard CO2 protocol, (ii) standard CO2 protocol conducted in front of a full-length mirror (mirror) and (iii) standard CO2 protocol conducted in front of a video camera deemed to be transmitting live images of the procedure to investigators evaluating participant performance (video). Despite counterbalancing for task order, there were significant differences in anger and depression among the conditions. Repeated measures analysis of variances (ANOVAs), controlling for these mood indices, revealed that salivary cortisol, heart rate and systolic blood pressure responses to the CO2 test were not affected by social evaluation (i.e. mirror or video). Although the data provide no evidence that endocrine and cardiovascular responses to the CO2 test are affected by social evaluation, the potency of the social evaluation manipulation in this study is in question. Thus, further research is warranted which includes evidence of, or instructions suggesting negative social evaluation.