 At least until the middle of the twentieth century, the individualistic-and-mentalistic theories were the prevailing approaches to the setup of the social world. These theories come in staggering variety. Even classical structuralism in anthropology (e.g., Lévi-Strauss 1945, 1963) falls into this class, holding that structures are unconscious sets of mental states. This brand of structuralism has an individualistic rather than a distributed theory of how structure determines a person’s social categories: each person, according to Lévi-Strauss, has a mental structure that determines his or her own social categories. Later versions of structuralism reject this individualistic treatment of structure.