Gustave Le Bon

The Crowd, published in 1895, argued that a person inside a group loses individual judgement and takes on the suggestibility of the mass, which can then be led by images and repeated assertion rather than by argument. It founded crowd psychology, and its influence ran in directions Le Bon did not choose: Mussolini said he had read it many times, and propagandists across the political range studied it closely. Le Bon trained as a physician and wrote on anthropology, physics and psychology, much of it now discarded, including skull measurements he used to rank races and to place women below men.