Group Psychology and the Analysis of the Ego
In Group Psychology and the Analysis of the Ego, (1922), Sigmund Freud based his preliminary description of group psychology on Le Bon's work, but went on to develop his own, original theory, related to what he had begun to elaborate in Totem and Taboo.
Theodor Adorno reprised Freud's essay in 1951 with his Freudian Theory and the Pattern of Fascist Propaganda, and said that "It is not an overstatement if we say that Freud, though he was hardly interested in the political phase of the problem, clearly foresaw the rise and nature of fascist mass movements in purely psychological categories.
Group Dynamics refers to a system of behaviors and psychological processes occurring within a social group (intragroup dynamics), or between social groups (intergroup dynamics). The study of group dynamics can be useful in understanding decision-making behavior, tracking the spread of diseases in society, creating effective therapy techniques, and following the emergence and popularity of new ideas and technologies..