We argue herein that, while often conceptualized as an extreme form of anger, hatred is a human emotion distinct from anger, with unique triggers, conceptual orientations, and terminating conditions. An examination of the social conditions of our species’ evolutionary history reveals that hatred evolved to address its own distinct adaptive problem: individuals whose existence was -- on balance -- costly to the hater. Because a well-designed system for solving this problem would have been tailored toward neutralizing those costs, we call this hypothesis ‘the neutralization theory of hatred.’ This theory places the features of hatred within a functional framework. Specifically, we argue that hatred is triggered by cues that an individual’s existence causes fitness decrements for the hater. Cognitively, hatred orients the mind so as to view costs heaped onto the hated person as benefits to the hater -- thus motivating spiteful behavior -- and can be characterized as maintaining a negative intrinsic welfare tradeoff parameter toward the hated person. Behaviorally, hatred can motivate either avoidance or a predatory style cost infliction strategy that is designed to weaken, incapacitate, or terminate the target. Hatred can be a dangerous emotion, and we believe a more thorough understanding of its evolved function is crucial for developing strategies that help mitigate its costs to society at large.