"Circuitry around revenge" is probably a beneficial social "skill" for facilitating group cooperation, there's all kinds of game theory (e.g. basic things like

"Circuitry around revenge" is probably a beneficial social "skill" for facilitating group cooperation, there's all kinds of game theory (e.g. basic things like iterated prisoners dilemma tit-for-tat strategy) that suggests that knowing about the presence of revenge acts and a likelihood of punishing defection (even at extra 'expense' for the punisher) deters defection, and allows to reach a better shared result. I.e. if we simply could abandon that at the flip of a switch, I'm not sure if we should, it's plausible that it would make all kinds of abuse less risky and thus more attractive, increasing the abuse happening in the world.