Two decades ago, in a monograph on ‘The Development of Social Sensitivity’, one of us concluded that: ‘The way is open for much more detailed and delicate study of the relationship between cognitive development and experience in a social environment’ (Light, 1979, p. 117). Research in the ensuing years has indeed added greatly to our understanding of this relationship, and the purpose of the present volume is to explore one particular aspect of it, namely the relationship between children's learning and their experience of interaction with peers.

In common with a great deal of the research undertaken in developmental and social psychology over the last twenty years, our subject matter can be embraced by the term ‘social-cognition’. However, this term encompasses a variety of very different research enterprises. On the one hand, we have research which is concerned with understanding of social phenomena. This encompasses perception and understanding of self and other, understanding others' intentions and emotions, and more generally the emergence of a ‘theory of mind’. On the other hand, we have research which examines the ways in which more general aspects of cognitive development are shaped by social interactions. Here we see traditional topics of cognitive developmental research such as reasoning and concept formation analysed in social-interactional terms.

As Butterworth and Light (1982) observed, the relationships between these various strands of research on socio-cognitive development have often been poorly defined and confusing.