Interaction, for all that it has an ethological base, is culturally constituted, and how new social members are enculturated into the interactional practices of the society is of critical interest to our understanding of interaction – how much is learned, how variable is it across cultures – as well as to our understanding of the role of culture in children’s social-cognitive development. The goal of this task is to document the nature of caregiver infant interaction in different cultures, especially during the critical age of 9-15 months when children come to have an understanding of others’ intentions. This is of interest to all students of interaction; it does not require specialist knowledge of children.