Interactive effects of caffeine consumption and stressful circumstances on components of stress: Caffeine makes men less, but women more effective as partners under stress

We tested the feasibility of the assertion that increased caffeine consumption exacerbates stress and disrupts dyad performance. We gave decaffeinated coffees, half of which contained caffeine, to coffee-drinkers in same-sex dyads and subsequently measured appraisals, emotional feelings, bodily symptoms of stress, coping behaviours, collaborative memory, collaborative psychomotor performance and negotiation skills under higher or lower stressful conditions. Results showed that caffeine impaired men’s, but improved women’s collaboration and collaborative performance under higher stressful conditions. They imply that male dyads under stress might benefit by avoiding extra caffeine-containing drinks. More generally, our findings are consistent with the idea that ‘tend and befriend’ not ‘fight or flight’ characterises women’s coping, and we argue that cognitive-relational theory provides a framework in which opposing effects of caffeine consumption and other variables on different components of stress may be integrated