An interesting paper in the snappily titled International Journal of Offender Therapy and Comparative Criminology examines what we know about the psychology of revenge.
It has a fascinating section where it discusses how often people take vengeful actions and whether they actually bring any relief.
It seems that taking revenge is rare, but when it happens, it is not only remarkably unsatisfying but counter-productive in terms of dispelling the desire for retribution.
Empirical research by Crombag, Rassin, and Horselenberg (2003) showed that most people do not actually take revenge but merely have thoughts, feelings, and fantasies about it (see also Crombag, 2003). Most people become reconciled with the offender and many people decide to let bygones be bygones. Some of the people who did take revenge could not explain their reason for doing so…
It should be noted that, in the study of Crombag et al., the group of people who took revenge even after a period of time still struggled with more vengeful feelings than the people who did not take revenge. Although 58% experienced satisfaction and 16% experienced triumph, only 19% reported their vengeful feelings to be completely gone, compared with 40% of the people who did not take revenge.
A 2008 study found that one reason that people who do take revenge find it hard to move on is that taking action keeps them ruminating about the events.
Link to locked paper on the psychology of revenge.