Group dynamics is 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 behaviour, tracking the spread of diseases in society, creating effective therapy techniques, and following the emergence and popularity of new ideas and technologies. These applications of the field are studied in psychology, sociology, anthropology, political science, epidemiology, education, social work, leadership studies, business and managerial studies, as well as communication studies.
The history of group dynamics (or group processes) has a consistent, underlying premise: 'the whole is greater than the sum of its parts.' A social group is an entity that has qualities which cannot be understood just by studying the individuals that make up the group. In 1924, Gestalt psychologist Max Wertheimer proposed ‘There are entities where the behaviour of the whole cannot be derived from its individual elements nor from the way these elements fit together; rather the opposite is true: the properties of any of the parts are determined by the intrinsic structural laws of the whole’ (Wertheimer 1924, p. 7). (The proposition remains questionable, since modern biologists and game theorists do look to explain the 'structural laws of the whole' in terms of 'the way the elements fit together'.)
As a field of study, group dynamics has roots in both psychology and sociology. Wilhelm Wundt (1832–1920), credited as the founder of experimental psychology, had a particular interest in the psychology of communities, which he believed possessed phenomena (human language, customs, and religion) that could not be described through a study of the individual. On the sociological side, Émile Durkheim (1858–1917), who was influenced by Wundt, also recognized collective phenomena, such as public knowledge.