Cortisol and moral decisions among young men : the moderating role of motivation toward closure

Previous research has demonstrated that under stress people make more deontological than utilitarian judgements. We however suggest that the relationship between stress and moral decisions may differ depending on which goals are accessible. In this study we focused on the goal to achieve certainty and individual differences in its importance, expressed as the need for closure. In particular, we examined whether the effects of individual variation in stress levels, measured by cortisol level, on moral decisions depended on individual differences in certainty importance, i.e., the need for closure. Male participants completed the Need for Closure scale and performed a moral decision making task. Saliva samples from these participants were collected. We found that cortisol level was associated with more utilitarian than deontological judgments when achieving certainty was a focal goal (i.e., high need for closure level) but only when ingroup was involved. When certainty reduction is not of such importance (i.e., low need for closure level), groups are not a crucial aid when navigating the social world. In this case, high cortisol levels were associated with more deontological than utilitarian decisions. This was true only for dilemmas in which ingroup was not involved.