Chapter 7, Language and Psychology, begins with a review of theories about the evolution of human language, focusing on biolinguistic and usage-based theories. The body of the chapter is devoted to the study of contemporary language use: How people use words to do things, usually things that involve other people. Such study is often based on the so-called action tradition in language studies. It focuses on language use as arising in people’s joint activities, including how meaning is typically negotiated and determined through both linguistic and nonlinguistic social interactions. Central concepts in these studies are joint activities, coordination, interactive repair, common ground, and social accountability. The chapter also contains a discussion of two ways of conceiving of how words get their meanings: the classical view and the anthropological view. After a discussion of different styles of thinking about language, we end the chapter by presenting suggestions for the psychological study of people’s talk and language use in social situations.