Development entails many changes. Most obviously, as children grow, they change physically. But development encompasses more than physical growth. It includes cognitive development as well. The ways in which children perceive and think about the world changes with development. Our emotions develop too. With emotional development, children broaden their capacity to feel complex emotions such as embarrassment, guilt, or pride. Children's understanding of emotion also changes. They learn new ways of expressing their emotions, and become better able to identity others' emotional expressions. A fourth area of growth is in social development, which involves changes in how children understand friendship and sharing, and how they interact with others.

Each of these domains of development (physical, cognitive, emotional, and social) interact with one another, influencing one another. For example, cognitive advancements may make other types of development possible. As our minds and thought capacities develop, it becomes possible to experience more complex emotions, and we begin to understand social relationships in a more intricate fashion. Social developments such as the capacity to share and cooperate have implications for emotional development because through forming friendships children learn how to care for others and empathize with them. Physical, cognitive, emotional, and social development all interact with one another in that development in one area has implications for the others. Textbooks and college courses often describe the different domains of child development separately, perhaps discussing physical development one week and cognitive development the next. However, when considering a particular child, we must consider all areas of development simultaneously.

An important theme of developmental psychology can be seen throughout the articles and links on these pages: the individual and environment interact reciprocally to produce development. What this means is that characteristics within the individual have the potential to influence the environment around him or her. For example, an infant with a difficult temperament may cry easily and may be a challenge to comfort. Conversely, an infant with an easy temperament may smile and laugh readily, and need little comforting. These behaviors potentially can influence the infant's environment in that parents may become exasperated at his or her behavior, may be more likely to ignore the infant, or may provide the infant with additional attention and play time. The notion that the interaction between individual and environment is reciprocal calls attention to the idea that the environment also influences the developing child. A parent's soothing voice and hug can soothe the difficult infant and, with time, may even change how she expresses her temperament. In terms of real-world application, this means that parents should be aware that characteristics of their children may influence their own behavior, and in turn, their own behavior holds implications for the development of their children.

-- Tara Kuther, Ph.D., is a professor of developmental psychology and freelance writer. Tara is the owner and editor of Growing Up, http://growing-up.8k.com, a free webzine and newsletter about all the forms that growth may take. Subscribe to Growing Up and learn about all the forms growth may take: physical, mental, emotional, developmental, personal, and more. Topics covered include psychology, development, writing, health, pregnancy, stuent development, and personal growth. Subscribe by sending a blank email to Growingup-subscribe@egroups.com