What is revenge? Revenge is defined as the action of inflicting harm or harm on someone for an injury or wrong suffered at their hands (Oxford definition). It can also be described as the act of a person inflicting harm on something that has already harmed them, in an attempt to try to restore justice. Vengeance has been a part of humans for as long as humans have existed. In fact, even before the emergence of humans, primates experienced conflict in their intragroup relationships. Primatologists (from Primatology, the study of primates) Frans de Waal and Lesleigh Luttrel conducted a study in which they would test revenge in three species of primates. One species (chimpanzees) has shown a notable tendency toward revenge. (McCullough 2008) Furthermore, besides primates, many animals, such as ants, also express explicit revenge behavior. In the case of ants, previously enslaved ants kill the captors' babies in order to make them "equal." (Pamminger et al., 2012) So what does this say about revenge? He says that the desire to acquire justice is not only in humans, but also in animals. If this feeling is also observed in animals, it is most likely an evolved trait. Revenge is viewed differently by almost everyone, meaning there is no definitive answer as to whether it is beneficial or not. The act of revenge has seen drastic changes in perspective throughout history. In the Middle Ages, conflicts would only be considered resolved when they were avenged. In fact, many long-established justice systems (similar to those practiced by the samurai class in Japan's feudal past, which consisted of "revenge for honor") are limited to vengeance alone. (Ikegami 1995) Even modern Western legal rules ... middle of paper ...... revenge Rosenbaum, T. (2013). Payback: an argument for revenge. Chicago: University of Chicago Press. McCullough, M. (2008). Beyond revenge: the evolution of the forgiveness instinct. San Francisco: Jossey-Bass. Tobias Pamminger, Annette Leingärtner, Alexandra Achenbach, Isabelle Kleeberg, Pleuni S. Pennings and Susanne Foitzik (2012). Geographic distribution of the antiparasitic trait “slave rebellion” Evolutionary Ecology Ikegami, E. (1995). The Taming of the Samurai: Honorary Individualism and the Creation of Modern Japan. Cambridge: Harvard University Press. Carlsmith, K. (May 2008) Journal of Personality and Social Psychology, (Vol. 95, No. 6). Jaffe, E. (October 2011.) The Complicated Psychology of Revenge. Observer Vol.24, No.8Revenge. (November 17, 2013). Wikipedia. Retrieved November 21, 2013 from http://en.wikipedia.org/wiki/Revenge