Testosterone and cortisol do not predict rejecting harm or maximizing outcomes in sacrificial moral dilemmas: a preregistered analysis

Contemporary moral psychology explores the biological underpinnings of morality, including how neuromodulators influence moral judgment and decision making. Some studies suggest that higher circulating testosterone is associated with increased acceptance of sacrificial harm, such as killing one person to save five lives, consistent with utilitarian ethics and inconsistent with deontological ethics. However, most studies employ conventional analytic techniques that conflate concern about outcomes with reduced concern about sacrificial harm, many are statistically underpowered, and none examine potential regulating effects of cortisol. Therefore, we examined whether salivary concentrations of testosterone and cortisol jointly predict sacrificial dilemma judgments among a large sample of undergraduates (n = 199). We utilized an advanced cognitive modeling technique (process dissociation) to independently assess sensitivity to causing harm and maximizing outcomes, preregistering the prediction that higher testosterone would predict reduced harm-rejection rather than increased concern for outcomes, especially among people low in cortisol. However, neither testosterone, nor cortisol, nor their interaction predicted sacrificial dilemma response tendencies. Such findings raise questions about the robustness of past evidence suggesting links between testosterone and sacrificial dilemma judgments.