Erik Erikson (1902-1994) is a psychologist most well known for his model on psychosocial development. Erikson’s focus on the social aspects of development, and the impacts of social influences on our development, differentiated his model from others and provided a framework that would progress the field of psychology for decades to come. Erikson’s stages of development theory details eight distinct and consecutive stages one progresses through to develop a healthy sense of self.
Piaget's Four Stages
Jean Piaget was a Swiss developmental psychologist who studied children in the early 20th century. Many branches of education and psychology use his theory of intellectual or cognitive development (1936). It focuses on children, from birth to adolescence, and characterizes different stages of development, including: language, morals, memory, and reasoning.