Here is a book that challenges the very basis of the way psychologists have studied child development. According to Urie Bronfenbrenner, one of the world’s foremost developmental psychologists, laboratory studies of the child’s behavior sacrifice too much in order to gain experimental control and analytic rigor. Laboratory observations, he argues, too often lead to “the science of the strange behavior of children in strange situations with strange adults for the briefest possible periods of time.” To understand the way children actually develop, Bronfenbrenner believes that it will be necessary to observe their behavior in natural settings, while they are interacting with familiar adults over prolonged periods of time. This book offers an important blueprint for constructing such a new and ecologically valid psychology of development. The blueprint includes a complete conceptual framework for analysing the layers of the environment that have a formative influence on the child. This framework is applied to a variety of settings in which children commonly develop, ranging from the pediatric ward to daycare, school, and various family configurations. The result is a rich set of hypotheses about the developmental consequences of various types of environments. Where current research bears on these hypotheses, Bronfenbrenner marshals the data to show how an ecological theory can be tested. Where no relevant data exist, he suggests new and interesting ecological experiments that might be undertaken to resolve current unknowns. Bronfenbrenner’s groundbreaking program for reform in developmental psychology is certain to be controversial. His argument flies in the face of standard psychological procedures and challenges psychology to become more relevant to the ways in which children actually develop. It is a challenge psychology can ill-afford to ignore.