Children learn about the world from the testimony of other people, often coming to accept what they are told about a variety of unobservable and indeed counter-intuitive phenomena. However, research on children’s learning from testimony has paid limited attention to the foundations of that capacity. We ask whether those foundations can be observed in infancy. We review evidence from two areas of research: infants’ sensitivity to the emotional expressions of other people; and their capacity to understand the exchange of information (...) through non-verbal gestures and vocalization. We conclude that a grasp of the bi-directional exchange of information is present early in the second year. We discuss the implications for future research, especially across different cultural settings. (shrink)