Xinyin Chen, PhD, is Professor of Psychology in the Applied Psychology–Human Development Division, Graduate School of Education, at the University of Pennsylvania in Philadelphia. He is a Fellow of the American Psychological Association and the Association for Psychological Science and a member of the Executive Committee of the International Society for the Study of Behavioral Development. Dr. Chen has received a William T. Grant Scholars Award, a Shanghai Eastern Scholars Award, and several other academic awards. His primary research interest is children’s and adolescents’ socioemotional functioning (e.g., shyness–inhibition, social competence, and affect) and social relationships from a cultural–contextual perspective. Kenneth H. Rubin, PhD, is Professor of Human Development and Director of the Center for Children, Relationships, and Culture at the University of Maryland in College Park. He is a Fellow of the Canadian Psychological Association, the American Psychological Association, and the Association for Psychological Science. Dr. Rubin is a recipient of the award for Distinguished Contributions to the International Advancement of Research and Theory in Behavioral Development from the International Society for the Study of Behavioral Development and of the Developmental Psychology Mentor Award from the American Psychological Association. He is currently a member of the Governing Council of the Society for Research in Child Development. Dr. Rubin’s research and publications address such topics as social competence, social cognition, play, aggression, social anxiety and withdrawal, and children’s peer and family relationships.