This paper makes a distinction between ahistorical causal-functional kinds and historical kinds, which include both type- and token-historical kinds, some of which are “copied kinds.” After showing how these distinctions play out in various social sciences, a number of reasons are put forward for the historical individuation of some social kinds. As in the natural sciences, historical individuation in the social sciences can enable us to infer common causes, explain synchronic causal properties, and discover exceptions to causal regularities, among other epistemic aims.