Socialization is the means by which human infants begin to acquire the skills necessary to perform as functioning members of their society.
In 1902, Charles Horton Cooley created the concept of the looking-glass self, which explored how identity is formed.
For Mead, the self arises out of the social act of communication, which is the basis for socialization.
According to Freud, human behavior, experience, and cognition are largely determined by unconscious drives and events in early childhood.
Piaget's theory of cognitive development is a comprehensive theory about the nature and development of human intelligence.
Daniel J. Levinson was one of the founders of the field of positive adult development.