JILL SAXON teaches at the University of Illinois, USA, where she also serves on the Bureau of Educational Research. nbsp; 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 Lawrence R. Kenan Jr. Professor of Psychology at the University of Virginia, USA. She has served as president of the Developmental Division of the American Psychological Association and as a member of the executive boards of the International Society for the Study of Infancy and the Cognitive Development Society. The holder of a Scientific MERIT Award from the National Insititutes of Health, she has also been recognized several times for outstanding undergraduate teaching. NANCY EISENBERG is Regent's Professor of Psychology at Arizona State University, USA. She has served on the board of directors of the American Psychological Society, on the governing board of the Society for Research in Child Development, on the council of the American Psychological Association, and as president of the Western Psychological Association. She has served as the editor of the Psychological Bulletin and been the recipient of several National Institutes of Health 'Career Development' and 'Career Scientist' awards.