Perhaps the broadest, most integrative approach in psychology is the HUMANISTIC perspective because it studies the whole person.
It appeared during the 1950s as a reaction to the psychoanalysis and behaviorism. It focuses on the study of the whole person and stresses the importance of growth and self-realization.
The psychoanalytic approach, on the other hand, is based on the theories of Sigmund Freud, which focus primarily on the unconsciousness and early childhood events.
The biological approach explains behavior only in terms of genetics and physiology.