Introduction The study of cognitive development in children has moved through three identifiable phases in the last twenty years. First, there was a shift from a focus on intellectual processes within the individual child, as in the classic research of Piaget, to a concern with social cognition in the 1970s and 1980s very much influenced by the resurgence of interest in Vygotsky. This shift reflects a move away from attempting to explain cognition as a process located solely within the individual, towards an understanding of the interpersonal context of cognitive growth. The shift from ‘cold blooded’ to ‘warm blooded’ cognition drew attention to the ways in which thought processes and cognitive growth are socially situated but contextual factors were for the most part seen only as moderators of cognitive growth. Work on cognitive development has recently entered a third phase, in which theorists are beginning to stress an inextricable link between contextual constraints and the acquisition of knowledge. Moreover, the physical context is being reunited with the social, within the thought process. The contemporary view tends to be that cognition is typically situated in a social and physical context and is rarely, if ever, decontextualized.