Cathryn Booth-LaForce is a developmental psychologist and the Charles and Gerda Spence Professor of Nursing in the Family & Child Nursing Department at the University of Washington. Her research focuses on individual differences and contextual influences on social-emotional development and relationships, within an attachment framework. Glenn I. Roisman is a Professor at the Institute of Child Development at the University of Minnesota. His program of research concerns the legacy of early interpersonal experience as an organizing force in social, cognitive, and biological development across the lifespan. John Ruscio is a Professor of Psychology at The College of New Jersey. His scholarly interests include taxometric methodology and its application, the science and policy implications of behavioral economics, citation-based indices of scholarly impact, and modern and robust statistical methods. Marinus H. van IJzendoorn is a Professor of Child and Family Studies at Leiden University, the Netherlands and a Research Professor of Human Development at Erasmus University Rotterdam, the Netherlands. His work concerns attachment and emotion regulation across the life span from a multidisciplinary perspective.