Erik Erikson's well-known stage theory of psychosocial development helped generate interest and inspire research on human development through the lifespan. An ego psychologist who studied with Anna Freud, Erikson expanded psychoanalytic theory by exploring development throughout the life, including events of childhood, adulthood and old age.

Learn more about his life, career, and contributions to psychology in this biography of Erik Erikson.

Looking for more information about Erik Erikson's theories?

• Psychosocial Stages Summary Chart
• Identity Crisis
• Psychosocial Development Quiz

Definition: Behavior analysis is a school of psychology based upon the foundations and principles of behaviorism. According to division of the of the American Psychological Association (APA) devoted to this area of psychology, behavior analysis "...promotes basic research, both animal and human, in the experimental analysis of behavior; it encourages the application of the results of such research to human affairs, and cooperates with other disciplines."

Learn more about behavior analysis.