During the First World War, when Vienna became home to over 100,000 refugees, many of them Jews from Galicia, Bernfeld became interested in developing new forms of Jewish education catering to the needs of these young Jews; in summer 1917 the Zionist organization in Vienna recruited him to lead its education and youth work.
[3] From 1917 to 1921 Bernfeld was in charge of Zionistischer Zentralrat für West-Österreich (Zionist Central Council for Western-Austria), and in 1919 he headed a project called Kinderheim Baumgarten, which provided housing and education for 300 Jewish children from Poland, who were displaced during the war.
[5] In a 1931 article published on the journal edited by Freud, Bernfeld defined psychoanalysis coining[6] the German term Spurenwissenschaft[7] ("science of traces").
He regarded educational reformer Gustav Wyneken (1875-1964) an early influence in his career, and was a member of several liberal and "youth culture" organizations.
Among his written works was an influential book on infant psychology called Psychologie des Säuglings, and a 1925 work on educational theory titled Sisyphos, in which Bernfeld advocates a non-authoritarian educational system that stresses the importance of the instinctual life and the needs of the student.