Special used in the psychological study of infants. One of the many experiments modeling the human in stages for children for children. Developmental psychology is the scientific study of how and why human beings change over the course of their life.
Developmental psychology examines the influences of nature and nurture on the process of human development, and processes of change in context and across time. Watson and Jean-Jacques Rousseau are typically cited as providing the foundations for modern developmental psychology. There are many theorists that have made a profound contribution to this area of psychology. For example, Erik Erikson developed a model of eight stages of psychological development. Sigmund Freud believed that we all had a conscious, preconscious, and unconscious level. In the conscious, we are aware of our mental process.