 Norms are the rules of a group of people that mark out what is appropriate, allowed, required, or forbidden for various members in different situations. They are typically manifest in common behavioral regularities that are kept in place by social sanctions. From an early age, humans see certain behaviors, contexts, and roles as governed by norms. Once a person adopts a norm, it functions both as a rule that guides behavior and as a standard against which behavior is evaluated. Moreover, individuals typically become motivated to enforce the norms they adopt, and so to participate in regulative practices such as punishment and the ascription of blame. Such practices in turn help stabilize the community’s social arrangements and the norms that structure them. Norms are often classified into kinds or subcategories, with common examples including moral, social, conventional, epistemic, aesthetic, and organizational norms. The correct or theoretically most useful way to distinguish and taxonomize kinds of norm is the subject of much debate, but one that will be set aside here (see O’Neill 2017 for a review, Kelly forthcoming for discussion). Rather, this section will sketch a general overview of the conceptual space common to cognitive-evolutionary work on the psychology of norms, and later sections will elaborate on its contents, locating different claims and specific theories within it.