How does an immature, disorganized, and dependent creature like an infant evolve into a walking, talking, and socially capable person in the span of two short years? This question is a puzzle that has long intrigued scientists, educators, and parents. Do innate biological processes and their maturation largely drive the process or is the infant’s development a consequence of parenting and the environment provided by parents? In this book, Dr. Calkins brings together a unique group of scientists, including HDFS faculty members Dr. Esther Leerkes and Dr. Roger Mills-Koonce, whose work addresses questions about infant development from a biopsychosocial perspective. The central theme of the book is that the child is a product of an array of biological, emotional, cognitive, and social experiences that interact in complex ways.