Keep your word. Love your neighbor. Help those in need. Only marry the child of your father’s sister. Stone those who have had sex out of wedlock. Kill outgroup members. Human moral communities have developed a variety of moral rules, injunctions, prescriptions, and suggestions. How are we to understand the origins and nature of human morality, both at the level of universal building blocks and the level of cultural variation and elaboration? As this volume illustrates, understanding human moral psychology is a truly interdisciplinary endeavor, drawing important contributions from psychologists, neuroscientists, philosophers, biologists, legal scholars, and many others. Our goal in this chapter is to illustrate the utility of taking an adaptationist approach from evolutionary biology to understand universal aspects of moral psychology. We first describe what it means to take an adaptationist approach. We next give several examples of how an adaptationist approach has informed the study of certain aspects of moral psychology. We then briefly conclude with what we see as the value of this approach to the study of moral psychology broadly.