Arespected developmental theorist who proposed a comprehensive life-span theory

He is Erik Erikson. Erik Homburger Erikson was an American developmental psychologist and psychoanalyst who is German born, known for his theory on psychosocial development of human beings. He may be most well-known for coining the phrase identity crisis.  Though Erikson does not have a bachelor's degree, he work for as a professor at prominent universities such as Harvard and Yale. He is also recognized with being one of the inventors of Ego psychology, which stressed the part of the ego as being more than a servant of the id.