Human beings navigate an incredibly complex social world in which the prediction of the actions of other people is important for success and even survival. This navigation is complex because the underlying causes of other people’s behavior-their thoughts, feelings, and intentions-are hidden from view. Yet, without making inferences to these hidden mental states the behavior of others is not just complex but inscrutable. Human life is even more complicated because it is embedded within the context of groups and social relationships. Like inferring people’s hidden thoughts and feelings, the perception of a “group” is also a mental construction built from inferences that go far beyond what is strictly observable. And yet like attributing mental states to individual people, making inferences about groups is immensely useful in navigating the social world. In this chapter, we focus on one aspect of this complex social navigation that bridges inferences about individuals and inferences about groups, namely the attribution of collective responsibility .