Developmental Psychology

The discipline that examines the changes that occur throughout the life [Page 149]span in humans' behavior and reasoning as a result of environmental, biological, and psychological factors. This branch of psychology attempts to answer the question of how individuals change as they age. Developmental psychology examines changes occurring throughout all stages of life, from conception, infancy, childhood, adolescence, and adulthood to old age. Since the focus of this discipline is on different areas of development and different influences on development, it is important to approach developmental psychology from different theoretical perspectives. An important concept in developmental psychology is that of “maturation.” Maturation refers to “those aspects of development that are primarily under genetic control and which are relatively uninfluenced by the environment” (Slater & Bremner, 2003, p. 5). When thinking about what contributes to development, age by itself has no impact on development, but maturation and the different experiences that intervene between the life stages are what influence development. Therefore, developmental psychologists study age-related changes and the different factors that underlie these changes. Developmental psychologists use a variety of research strategies to answer questions related to development. To study behavioral changes related to age, both cross-sectional and longitudinal studies are employed. These types of research designs are combined with research methods to study development. The research methods most frequently employed include observational, experimental, and correlational technique, as well as psychological assessment. Observational studies involve repeated observations of the same individual at different points of time. Experimental studies are aimed at finding the causes of development, whereas correlational studies investigate the associations between variables. Finally, developmental psychologists employ a varied number of tests that are frequently used for clinical and educational assessment purposes. For more information, see Slater and Bremner (2003).