Witnesses of moral violations stand up for their moral principles, despite facing substantial costs for intervening. Notwithstanding its importance, little is known whether responsibility attributions and the relation between the victim and a witness (i.e., kinship) have different effects on the intention to intervene in situations of different severity (e.g., moral courage situations). We predict an interaction between the situation’s severity and the victims’ responsibility for their plight. In less-severe situations, witnesses would be less willing to help when they perceive the victim to be responsible for their plight. However, those who are not seen as responsible would receive more help. For more-severe situations, responsibility is predicted to have no effect. Opposite effects are predicted for the relationship between the helper and the victim. We further predict that perceived costs for helping mediates witnesses’ willingness to intervene. Two studies showed that people are more willing to help individuals who are perceived as being innocent in their plight, but only in less-severe situations. In more-severe situations, people’s willingness to intervene increases, regardless of responsibility attributions. We did not observe effects for kinship. Moreover, we provide partial evidence that witnesses of more-severe situations indeed accept higher costs for intervention.

As social creatures, humans' lives involve following group norms and maintaining relationships. Occasionally, people's group membership or relationship with others becomes threatened, activating the ostracism detection system (Spoor & Williams, 2007), which triggers behavior intended to protect from further social threats (