american developmental psychologist
He was trained in psychoanalysis at the vienna psychoanalytic institute. Was an ego phychologist studying the stages of development throughout the entire life span. He believed that human being goes through a certain number of stages to reach his or her full development theorizing eight stages that a human goes from birth to death . He had private practice in child psychoanalysis. He published a number of books like the "Childhood and society" as well as "The life cycle completed"