Human Development or Lifespan Development is the scientific study of the ways in which people change, as well as remain the same, from conception to death. You will discover that the field, known more broadly as developmental science, examines changes and stability across multiple domains of psychological and social functioning. These include physical and neurophysiological processes, cognition, language, emotion, personality, moral, and psychosocial development, including our relationships with others.

Originally concerned with infants and children, the field has expanded to include adolescence and more recently, aging and the entire life span. Previously, the message was once you are 25, your development is essentially completed. Our academic knowledge of the lifespan has changed, and although there is still less research on adulthood than on childhood, adulthood is gaining increasing attention. This is particularly true now that the large cohort known as the “baby boomers” are beginning to enter late adulthood. The assumption that early childhood experiences dictate our future is also being called into question. Instead, we have come to appreciate that growth and change continues throughout life and experience continues to have an impact on who we are and how we relate to others. We now recognize that adulthood is a dynamic period of life marked by continued cognitive, social, and psychological development.

You will also discover that developmental psychologists investigate key questions, such as whether children are qualitatively different from adults or simply lack the experience that adults draw upon. Other issues they consider include the question of whether development occurs through the gradual accumulation of knowledge or through qualitative shifts from one stage of thinking to another, or if children are born with innate knowledge or figure things out through experience, and whether development is driven by the social context or something inside each child. From these questions, you may already be thinking that developmental psychology is related to other applied fields. You are right. Developmental science informs many applied fields, including, educational psychology, developmental psychopathology, and intervention science. It also complements several other basic research fields in psychology including social psychology, cognitive psychology, and cross-cultural psychology. Lastly, it draws from the theories and research of several scientific fields including biology, sociology, health care, nutrition, and anthropology.

In this section:

• 1.1 The Lifespan Perspective
• 1.2 Domains of Development
• 1.3 Age and Periods of Human Development