Kurt Lewin (1890-1947) was a German psychologist, who emigrated to the United States to flee the Hitler's Nazi regime. Lewin accomplished most of his work before coming to the United States. Although he worked in the United States for a relatively short time, Lewin had a major influence on American functional psychology in general and on specific areas, such as Gestalt psychology, applied psychology and, particularly, social psychology. Lewin established the Research Center for Group Dynamics at the Massachusetts Institute of Technology. This center is still active, although it has moved to the University of Michigan.
With a background in physics and mathematics, Lewin applied concepts of field theory to psychology. Field theory in psychology was based on the idea of force fields in physics. Here we can see the influence of Lewin’s background in physics. Field theory postulated that human functioning occurs within a whole physical and social context, which Lewin called a psychological field or the life space. Within this psychological life space are the person’s representations of all of his or her past, current, and future events, including thoughts and feelings. At any one time, the persons’ emotions, ideas, and behavior are a function of all of those events brought to bear on the particular moment. Essentially, the person perceives the world and interacts with the world through a filter--the psychological life space. This is the person’s immediate reality, more so than the actual physical world.
Thus, a person does not simply respond to each external stimulus, as the behaviorists maintained. Rather, each person responds to the whole, the totality of each moment as represented within one’s life space. It is the relationships among the parts of the life space that determine one’s functioning. In this concept, Lewin had clearly been influenced by Gestalt ideas about perception. It is the interactions among one’s cognitive representations of the objective world in this life space that determine the person’s behavior. This puts Lewin clearly into the Gestalt tradition, focusing on wholes and relationships among parts, rather than on the parts themselves.
Lewin’s model also reflects the functionalist movement. Although not schooled in American functionalism, he conceptualized psychology in largely practical terms. He was interested in social issues and ways of making one’s environments more conducive to productivity, as well as more personally satisfying. Like other Gestalt and functional psychologists, Lewin was critical of the elementalism of both structuralism and behaviorism.
Lewin also applied this personal psychological life-space concept to social groups and became a major contributor to social psychology. A social group and its environment, he reasoned, forms a social field. This concept parallels that of the individual’s psychological field. Within that social field, the various parts--persons, ideas, experiences--are in dynamic interaction, and it is those interactions that produce, not only the behavior of individuals, but also the behavior of groups. Lewin, more than any one else, turned social psychology to the study of group dynamics.
With his field theory of the psychology of individuals and groups, Lewin studied how various types of groups functioned, comparing democratic, laissez faire, and authoritarian groups. He was also interested in the application of field theory principles to practical ends, such as reducing prejudice. Sensitivity training, for example, is one of the results of Lewin’s work.