Michael Siegal is Professor of Psychology at the University of Sheffield. He has researched and taught internationally and has published extensively in the area of developmental psychology. Siegal is the author of Knowing Children: Experiments in Conversation and Cognition, 2nd edition (1997) and co-editor with Candida C. Peterson of Children's Understanding of Biology and Health (Cambridge, 1999). He has served on the editorial boards of Child Development, Developmental Science, and Developmental Psychology, and is an Associate Editor of the British Journal of Developmental Psychology.