This chapter is about how children learn to use language for collective thinking, and how other people help them do so. It is also about how the process of communicating with language contributes to children’s intellectual development. To begin, here is some talk which I recorded while three children were playing together at home. Kay was 5 at the time, while her brother Alec and his friend Robert were both 9. She was listening to them telling each other jokes of the question-and-answer type.