Sex differences in cortisol excretion during anticipation of a psychological stressor: possible support for the tend-and-befriend hypothesis

The present experiment tested the hypothesis that differential neuroendocrine elicitation is prompted by subjects' cognitive expectations of an anticipated stressor. Subjects making a 'threat appraisal' of an academic examination were predicted to have increased hypothalamic-pituitary-adrenal (HPA) activation, while activation was expected to be unchanged in subjects making a 'challenge appraisal.' Self-reported anxiety in relation to these variables was also examined. HPA activation was assessed by urinary cortisol at baseline (at least 1 week before the examination) and at. pre-test (immediately before the examination). Contrary to the hypothesis, there was an unexpected sex x time interaction that was particularly robust in subjects making a challenge appraisal. Males in the challenge appraisal group had a significant increase in cortisol excretion from baseline to pre-test, with greater reported anxiety than the threat appraisal group. In contrast, females had a decrease in cortisol excretion that was significant for only the challenge appraisal group, although reported anxiety between the challenge and threat groups was not different, Results may support the recent proposition that the female stress response has evolved differently than that of males, or they may reflect sex differences in production of corticosteroid-binding globulin. Copyright (C) 2001 John Wiley & Sons, Ltd.