According to the social psychologist Gustave Le Bon, Contagion theory states that crowds exert a hypnotic influence over their members through collective suggestibility. According to this theory, people tend to give up their personal responsibility and surrender to the emotions of the crowd them. They feel shielded by the anonymity of the crowd and hence abandon responsibilities. A crowd may therefore stir up emotions, assuming a life of its own, and drive people into irrational behaviour. According to this theory whether the crowd is organized or spontaneous, they are bonded (hypnotism or imitation) together with charismatic figures. Le Bon was considered the founder of crowd psychology. Le Bon's The Crowd: A Study of the Popular Mind in 1895, influenced a lot of people which included Adolf Hitler. In fact his autobiography Mein Kampf mentions Le Bon's work.
