Psychology of human nature and its understanding is the key to smooth
interactions between two human beings. It is of great importance to dental surgeons
and dental nurses who are dealing with persons in times of distress. These are various
theories of developmental psychology given by different authors. The psychosexual
theory by an Austrian neurologist Dr. Sigmund Freud and the psychosocial theory by
Erik Erikson are the two main theories that explain psychological development and
maturity. They have important dental implications, which are discussed in this chapter.
The theory of classical conditioning, as given by Ivan Pavlov, a Russian physiologist,
is discussed
Keywords: Id, Ego, Superego, Classical Conditioning, Psycho-sexual Theory, Psychosocial Development, Thanatos.
