Alan Fogel is Professor of Psychology in the Department of Psychology at the University of Utah. He has written and edited many books including Change Processes in Relationships: A Relational-Historical Research Approach (Cambridge, 2006). Barbara J. King is Professor in the Department of Anthropology at the College of William & Mary. She is the Editor of the Journal of Developmental Processes. Stuart G. Shanker is Distinguished Research Professor of Philosophy and Psychology at York University, Toronto where he is also President of the Council for Early Child Development and Director of the Milton and Ethel Harris Research Initiative.