Bernays combined the ideas of French sociologist Gustave Le Bon, originator of crowd psychology, with the psychoanalytical ideas of his uncle, Sigmund Freud , and those of British surgeon and social psychologist Wilfred Trotter, who promoted similar ideas in the anglophone world in his book Instincts of the Herd in Peace and War.
"Trotter, who was a head and neck surgeon at University College Hospital, London, read Freud's works, and it was he who introduced Wilfred Bion, whom he lived and worked with, to Freud's ideas. When Freud fled Vienna for London after the Anschluss, Trotter became his personal physician, and Wilfred Bion and Ernest Jones became key members of the Freudian psychoanalysis movement in England, and would develop the field of Group Dynamics, largely associated with the Tavistock Institute where many of Freud's followers worked. Thus ideas of group psychology and psychoanalysis came together in London around World War II.
"Bernays' public relations efforts helped to popularize Freud's theories in the United States. Bernays also pioneered the PR industry's use of psychology and other social sciences to design its public persuasion campaigns:
"If we understand the mechanism and motives of the group mind, is it not possible to control and regiment the masses according to our will without their knowing about it? The recent practice of propaganda has proved that it is possible, at least up to a certain point and within certain limits." He called this scientific technique of opinion-molding the 'engineering of consent'" (Wikipedia article on Edward Bernays, accessed 02-17-2012).