Predicting Social Behavior: Basal and Dynamic Joint Effects of Testosterone and Cortisol

Abstract

There is growing evidence that steroid hormones interact to shape social behavior. In particular, regarding basal hormonal levels, cortisol has repeatedly been found to moderate the effect of testosterone on behavior. However, the role of contextual and hormone-altering factors such as acute stress on dual-hormone associations is largely unknown. In the present study, we aimed to evaluate whether baseline testosterone and cortisol levels predict dominance- and friendliness-related social behavior. Additionally, we focused on the moderating role of acute stress. In a laboratory study, 42 female and 38 male participants were allocated to same-sex dyads. Each dyad member was randomly assigned to a stress or control condition. Subsequently, the dyads performed a competitive role-play. Salivary cortisol, testosterone and mood levels were repeatedly assessed. Social behavior (dominance and friendliness) was rated based on the videotaped role-plays. For the combined sample of men and women in the stress condition, we found a negative relation between basal testosterone levels and friendliness, but only when basal cortisol levels were low. Interactions between testosterone and cortisol responses did not predict social behavior. In conclusion, our findings provide first evidence for the dual-hormone hypothesis in the context of interpersonal theory and reinforce the relevance of considering contextual factors such as acute stress.