Everyday moral decision-making after acute stress exposure: do social closeness and timing matter?

There is increasing empirical evidence that social distance and timing affect prosocial behavior after acute stress exposure. The present study focused on everyday moral decision-making after acute psychosocial stress and how it is influenced by effects of social closeness and timing. We exposed 40 young healthy men to the Trier Social Stress Test (TSST, n = 20) or its non-stressful placebo version (PTSST, n = 20). Moral decision-making was assessed early (+10 until +30 min) and late (+75 until +95 min) after (P)TSST exposure by the Everyday Moral Conflict Situations (EMCS) Scale. The EMCS Scale requests altruistic versus egoistic responses to everyday moral conflict situations with varying closeness of target persons. Results revealed significantly higher total percentages of altruistic decisions in the stress than in the control condition and for scenarios involving socially close (e.g., mother) versus socially distant (e.g., stranger) protagonists, while the main effect of timing was nonsignificant. Only secondary analyses showed increased altruistic decision-making after acute stress exposure toward socially close but not toward distant protagonists at the early but not at the late point of measurement. Moreover, psychological stress responses and personality traits were significantly associated with EMCS scores. Positive correlations between cortisol levels and altruistic decision-making were descriptively observable, but did not reach statistical significance. In sum, our findings suggest increased altruistic decision-making toward socially close compared to socially distant protagonists and provide further evidence that acute stress influences decision-making in everyday moral conflict scenarios in a prosocial manner.Lay summaryIn order to investigate the effects of acute stress on everyday moral decision-making, 40 young healthy men were exposed to moderate psychosocial stress by the use of the Trier Social Stress Test (TSST) or its non-stressful placebo version and then completed a hypothetical everyday moral decision-making paradigm. Our findings provide evidence that acute stress exposure influences decision-making in everyday moral conflict situations in a prosocial manner. Furthermore, participants decided more altruistically in scenarios involving socially close (e.g., mother) versus socially distant (e.g., stranger) protagonists.