In Vengeance Is Ours, Jared Diamond (Guns, Germs, and Steel, Collapse) looks at what tribal societies can tell us about our need to get even:
We regularly ignore the fact that the thirst for vengeance is among the strongest of human emotions. It ranks with love, anger, grief, and fear, about which we talk incessantly. Modern state societies permit and encourage us to express our love, anger, grief, and fear, but not our thirst for vengeance. We grow up being taught that such feelings are primitive, something to be ashamed of and to transcend.There is no doubt that state acceptance of every individual’s right to exact personal vengeance would make it impossible for us to coexist peacefully as fellow-citizens of the same state. Otherwise, we, too, would be living under the conditions of constant warfare prevailing in non-state societies like those of the New Guinea Highlands. In that sense, [Holocaust-survivor] Jozef was right to leave punishment of his mother’s killer to the Polish state, and it was tragic that the Polish state failed him so shamefully. Yet, even if the killer had been properly punished, Jozef would still have been deprived of the personal satisfaction that Daniel enjoyed.
My conversations with Daniel [who had his uncle's killer paralyzed with an arrow] made me understand what we have given up by leaving justice to the state. In order to induce us to do so, state societies and their associated religions and moral codes teach us that seeking revenge is bad. But, while acting on vengeful feelings clearly needs to be discouraged, acknowledging them should be not merely permitted but encouraged. To a close relative or friend of someone who has been killed or seriously wronged, and to the victims of harm themselves, those feelings are natural and powerful. Many state governments do attempt to grant the relatives of crime victims some personal satisfaction, by allowing them to be present at the trial of the accused, and, in some cases, to address the judge or jury, or even to watch the execution of their loved one’s murderer.
Daniel concluded his story in the same happy, satisfied, straightforward tone in which he had recounted the rest of it. “Now, when I visit an Ombal village to play basketball, and Isum comes to watch the game in his wheelchair, I feel sorry for him,” he said. “Occasionally, I go over to Isum, shake his hand, and tell him, ‘I feel sorry for you.’ But people see Isum. They know that he will be suffering all the rest of his life for having killed Soll. People remember that Isum used to be a tall and handsome man, destined to be a future leader. But so was my uncle Soll. By getting Isum paralyzed, I gained appropriate revenge for the killing of my tall and handsome uncle, who had been very good to me, and who would have become a leader.”