In 1902 Charles Horton Colley presented the theory of looking glass self is a social psychological concept which is interested in how a biological person becomes a social person. He realizes that this involves the process of socialization. He states that infants have no conception of the world as being separate from themselves. This understanding is linked to the learning of language.
Sigmund Freud was a physician who proposed the most controversial theory of psychosexual development which points to personality development over the course of childhood. According to Freud theory parents perform a crucial role in their children’s sexual and aggressive derives.