To defer or to stand up? How offender formidability affects third party moral outrage

According to models of animal behavior, the relative formidability of conspecifics determines the utility of deferring versus aggressing in situations of conflict. Here we apply and extend these models by investigating how the formidability of exploiters shapes third party moral outrage in humans. Deciding whether to defer to or stand up against a formidable exploiter is a complicated decision as there is both much to lose (formidable individuals are able and prone to retaliate) and much to gain (formidable individuals pose a great future threat). An optimally designed outrage system should, therefore, be sensitive to these cost- benefit trade-offs. To test this argument, participants read scenarios containing exploitative acts (trivial vs. serious) and were presented with head-shot photos of the apparent exploiters (formidable vs. non-formidable). As predicted, results showed that, compared to the non- formidable exploiter, the formidable exploiter activated significantly more outrage in male participants when the exploitative act was serious. Conversely, when it was trivial, the formidable exploiter activated significantly less outrage in male participants. However, these findings were conditioned by the exploiters' perceived trustworthiness. Among female participants, the results showed that moral outrage was not modulated by exploiter formidability.