Even Murderers Benefit From Expressing Guilt and Deontological Beliefs

In four experiments with N = 1178, we study the impact of wrongdoers’ moral beliefs and emotions on their morality judgments. We establish a moral superadditivity effect, whereby jointly signaling socially desirable deontological beliefs (“What I did is unacceptable”) and socially desirable moral emotions (“I feel guilty”) made that participants evaluated such wrongdoer as much less immoral. Even if participants judged a person who murdered their parents or many innocent people in a terrorist plane attack, the effect appeared. This effect was visible when comparing several transgressors (Studies 1 and 2) but disappeared when judging them independently, both for more severe and less profound unethical behaviors (Studies 3 and 4). Additionally, internal metanalysis showed that the benefits of expressing guilt and deontological beliefs were of similar strength and that both were much larger when participants compared different emotions and beliefs of wrongdoers directly.