A major task facing all humans is to make sense of the actions of others. Unsurprisingly, given the importance of meeting this challenge, humans everywhere display dedicated capacities that enhance our ability to interpret and predict the behavior of others. On one hand, humans readily mentalize--that is, they attribute to others unseen mental states and expect that these mental states systematically give rise to action. On the other hand, humans readily recognize others as being *sorts* of people, occupying *sorts* of roles, and they use this information to understand others' behavior. This seminar explores these capacities, particularlly the psychological and social mechanisms that subserve them. Of particular interest is how these capacities develop, both over an individual's lifetime, evolutionarily, and comparatively across cultural environments and across species.