In psychoanalytic theory, it's the first & most primitive stage of development
... Freud argued that children then passed through a stage where they 
fixated on... [DOC] [TLE] Psychodynamic Theories [PAR] the theory was spread beyond its Viennese origins by an ardent and dedicated 
group of followers ... family and Philipp moved to England, and the Jacob Freud 
family moved first to ...... more primitive stage of development (Freud, 1917/1963).