ABSTRACT
Two questions have guided most of developmental psychology: What is the typical course of development? And what are the causes of individual differences in development? The first question is the easier of the two to address, because it merely requires description. Using careful, sometimes painstaking, observational methods, researchers have identified milestones across a wide range of behaviors. Importantly, there is agreement about stages, phases, and sequences of development. By most standards, developmentalists have made good progress in describing normative development.
