Biographical note

Robert Siegler is the Teresa Heinz Professor of Cognitive Psychology at Carnegie Mellon University, USA. He has served as Associate Editor of Developmental Psychology journal. In 2005 he received the American Psychological Association's Distinguished Scientific Contribution Award. Judy DeLoache is the William R. Kenan Jr. Professor of Psychology at the University of Virginia, USA. She has published extensively on aspects of cognitive development in infants and young children. Dr. DeLoache has served as president of the Developmental Division of the American Psychological Association and as a member of the executive board of the International Society for the Study of Infancy. She was recently inducted into the National Academy of Arts and Sciences. Nancy Eisenberg is Regent's Professor of Psychology at Arizona State University, USA. She is editory or author of numerous books on prosocial, social, and emotional development. Dr. Eisenberg has served on the board of directors of the American Psychological Society, on the governing board of the Society for Research in Child Development, and is the founding editor of Child Development Perspectives. Jenny Saffran is the College of Letters and Science Professor of Psychology at the University of Wisconsin-Madison, USA. She received her PhD from the University of Rochester in 1997, and specializes in statistical learning in language development.