The theories and practice of Sigmund Freud, the founder of psychoanalysis, were familiar to certain sections of society during the early 1920s.
Freud suggested that children between approximately the ages of 3 and 5 pass through a psychic developmental stage during which they experience unconscious sexual desires for the parent of the opposite sex and a corresponding desire to get rid of the same-sex parent, who is their 'rival'. He used the term Oedipus complex to describe this constellation of feelings in both boys and girls, although Carl Jung preferred 'Electra complex', for the female experience.
Freud practised psychoanalysis in Vienna, where he and a group of like-minded followers formed the Vienna Psychoanalytical Society in 1908. James Strachey and Alix Strachey (the brother and sister-in-law of Lytton Strachey, an important member of the Bloomsbury group,) are said to have been analyzed by Freud in Vienna in the early 1920s.*
*Noted by Phyllis Grosskurth in her 1986 biography of Melanie Klein (p.123).