Infant Development: The First 3 Years of Life

For those interested in human behavior, developmental science is an essential body of knowledge. The first 3 years of life is a period of rapid change across all domains of development, with the importance of experiences during this initial postnatal window increasingly well documented. The chapter begins by considering theories of development, which address the content of development, and models of development, which address the process of development. The importance of culture as a central context defining the meaning of child and parenting behavior and assigning value to beliefs and practices will be emphasized. The conceptual framework employed describes 3 periods of major qualitative changes in the first 3 years of life. These biobehavioral shifts, occurring roughly at 2–3 months, 7–9 months, and 18–20 months, are periods in which new capacities and behaviors emerge that have not been apparent earlier. The development of the domains of biological-neurological, emotional, social, communicative, and cognitive development are described within each of the 4 periods that these 3 biobehavioral shifts demarcate. The chapter concludes with a discussion of risk and protective factors that influence developmental trajectories of young children. The main, mediating, and moderating effects of risk and protective factors and mechanisms have enormous implications for our understanding of psychopathological processes and their prevention and treatment.