theories Dynamic approachesis Involve a search for the processes by which needs , motives , impulse often hidden from view in treat to produce the individual's behavior , Frend's psychoanalysis " 1920 1949 " become both a theory of personality and method of psychotherapy psychoanalytic theory has three major parts . 1.a theory of structure of personality , in which the ego , id , and superego the principle parts . 2.a theory of personality dynamics , in which conscious and unconscious motivation and ego - defense mechanisms play a major role . 3.a theory of psychosexual development , in which different motives and body regions influence the child different stages of growth , with effects persisting in the form of adult personality traits . 1. Personality structure :