In this chapter, I critically examine issues relevant to the construction and reality of social categories, focusing on issues concerning conceptual schemes and conventionalism. Conceptual schemes (‘paradigms,’ ‘linguistic frameworks,’ ‘forms of life’) are systems of concepts that organize and give (intersubjective) meaning to empirical experience. In discussions about the construction of social categories, a common assumption is that social categories and kinds (e.g., ‘money,’ ‘marriage,’ ‘liberal’) require the presupposition of a conceptual scheme that gives meaning to those terms. One prominent (...) position in social ontology (Lewis, 1969, Gilbert 1989, 2014, Searle 1995) holds that the reality of social categories is grounded in a conventionalist conceptual scheme: social categories are conventionally accepted categories that reflect explicit or implicit agreements within a community. According to this view, the reality of social categories and kinds is established (and maintained) by contingent and arbitrary conventional decisions about social categories (e.g., laws about legal tender, marriage laws, the one-drop rule). Conventions can be understood as social customs (e.g., rules governing traffic, marriage laws, institutionalized rules about sex and gender) that serve some human purpose or interest. They are important for the establishment and maintenance of social norms (see Bicchieri 2006, 2017). -/- The chapter proceeds as follows. In section 2, I examine the general idea of conceptual schemes, focusing on Kuhn’s influential theory of paradigms. While Kuhn’s position implies a conceptual relativity and anti-realism (or instrumentalism) about scientific concepts, Davidson and Popper challenge the Kuhnian orthodoxy that the presence of conceptual schemes implies conceptual relativity or ‘incommensurability’ of competing conceptual schemes. I argue that a key difference between scientific and social conceptual schemes is that the former are oriented towards describing nature, whereas the latter are oriented towards social utility or usefulness. In section 3, I examine some foundational works in social ontology—focusing on the accounts of Lewis, Gilbert, and Searle—that hold that social categories are grounded by a conventionalist conceptual scheme. These accounts of social categories imply that the reality of social categories is constituted by (or grounded in) social conventions, which ultimately reflect (or are anchored by) explicit or implicit community-level agreements. In section 4, I survey some prominent accounts of social human categories, focusing on the views of Hacking, Khalidi, Mallon, Haslanger, and Ásta. A common tendency in these accounts is the portrayal of social categories as social to the extent that they are conventionally determined. This suggests that the proper contrast class for social categories is natural categories (as opposed to individual categories or innate categories). (shrink)