Rob Kurzban: Penn Psychology

Substantial debate remains about the ultimate and proximate explanations for why people choose to punish
third parties, individuals involved in interactions that have had and will have no direct effect on the punisher.
Here, one particular type of third-party punishment is explored, moralistic punishment, enduring a cost to inflict
costs on an individual who has violated a perceived moral norm. Results from a series of experiments
suggest that 1) third-party punishment, at least in these cases, is considerably less frequent and smaller in
magnitude than would be expected from existing models, 2) knowing that one will be observed in meting out
moralistic punishment increases individuals’ willingness to do so, and 3) inducing emotions such as
empathy has systematic effects on both moralistic punishment and compensating victims of moral wrongs.
These findings are discussed in the context of possible evolved functions of moral psychology, focusing on
the centrality of moralistic punishment for understanding the nature of the moral game being played.