Some unpleasant emotions, like fear and disgust, appear straightforwardly susceptible to evolutionary explanation on account of the benefits they seem to provide to individuals. But guilt is more puzzling in this respect. Like other unpleasant emotions, guilt is often associated with a host of negative effects on the individual, such as psychological suffering and social withdrawal. Moreover, many guilt-induced behaviors, such as revealing one’s offenses and placing oneself before the mercy of others, could levy a cost to individuals that is (...) not outweighed by guilt’s benefits. Supposing there is an evolutionary story to tell about the origins of guilt, the question is how such negative effects were sufficiently outweighed by the potential fitness payoffs that guilt might have yielded to individuals. In this article, we consider which forms of evolution could have resulted in guilt, and whether current evidence can tell us which form of evolution most likely occurred. (shrink)