A meta-analytical evaluation of the dual-hormone hypothesis: Does cortisol moderate the relationship between testosterone and status, dominance, risk taking, aggression, and psychopathy?

According to the dual-hormone hypothesis, the relationship between testosterone and status-relevant behavior is moderated by cortisol, suggesting this relationship only exists when cortisol is low. In the current study, a meta-analysis (including 30 papers with 33 studies, 49 effect sizes, n = 8538) on the interaction effect of testosterone and cortisol on status-relevant behavior (i.e. status, dominance, risk taking, aggression, and psychopathy) was performed. There was only marginal support for the dual-hormone hypothesis: The effect size of the interaction between testosterone and cortisol on status-relevant behavior was significant but very small (r = -.061, p =  .026), which was corroborated by follow-up meta-analyses on simple slopes on low and high cortisol. Effect sizes were largest for direct status measures, although not significantly different from other outcome measures. Similarly, effect sizes seemed larger for men than for women. However, robustness analyses indicated signs of publication bias, enhanced significance due to potential flexibility in data-analysis, and a lack of power of individual studies, emphasizing the need for a large, pre-registered study.