September 9, 1890
February 12, 1947
|Citizenship||Germany, United States|
|Institutions||Institute for Social
Center for Group Dynamics (MIT)
National Training Laboratories
|Alma mater||University of Berlin|
|Doctoral advisor||Carl Stumpf|
|Doctoral students||Leon Festinger,
|Known for||Group Dynamics, Action research, T-groups|
|Influenced||Fritz Perls, Abraham Maslow,M. Pat Korb, Brian J. Mistler, Eric Trist, David A. Kolb|
In 1890, he was born into a Jewish family in Mogilno, Poland (then in County of Mogilno, province of Posen, Prussia). He served in the German army when World War I began. Due to a war wound, he returned to the University of Berlin to complete his Ph.D., with Carl Stumpf (1848 - 1936) the supervisor of his doctoral thesis.
Lewin had originally been involved with schools of behavioral psychology before changing directions in research and undertaking work with psychologists of the Gestalt school of psychology, including Max Wertheimer and Wolfgang Kohler. Lewin often associated with the early Frankfurt School, originated by an influential group of largely Jewish Marxists at the Institute for Social Research in Germany. But when Hitler came to power in Germany in 1933 the Institute members had to disband, moving to England and then to America. In that year, he met with Eric Trist, of the London Tavistock Clinic. Trist was impressed with his theories and went on to use them in his studies on soldiers during the Second World War.
Lewin emigrated to the United States in August 1933 and became a naturalized citizen in 1940. Lewin worked at Cornell University and for the Iowa Child Welfare Research Station at the University of Iowa. Later, he went on to become director of the Center for Group Dynamics at MIT. While working at MIT in 1946, Lewin received a phone call from the Director of the Connecticut State Inter Racial Commission requesting help to find an effective way to combat religious and racial prejudices. He set up a workshop to conduct a 'change' experiment, which laid the foundations for what is now known as sensitivity training. In 1947, this led to the establishment of the National Training Laboratories, at Bethel, Maine. Carl Rogers believed that sensitivity training is "perhaps the most significant social invention of this century." 
Following WWII Lewin was involved in the psychological rehabilitation of former occupants of displaced persons camps with Dr. Jacob Fine at Harvard Medical School. When Eric Trist and A T M Wilson wrote to Lewin proposing a journal in partnership with their newly founded Tavistock Institute and his group at MIT, Lewin agreed. The Tavistock journal, Human Relations, was founded with two early papers by Lewin entitled "Frontiers in Group Dynamics". Lewin taught for a time at Duke University.
Lewin coined the notion of genidentity, which has gained some importance in various theories of space-time and related fields. He also proposed Herbert Blumer's interactionist perspective of 1937 as an alternative to the nature versus nurture debate. Lewin suggested that neither nature (inborn tendencies) nor nurture (how experiences in life shape individuals) alone can account for individuals' behavior and personalities, but rather that both nature and nurture interact to shape each person. This idea was presented in the form of Lewin's Equation for behavior B=ƒ(P,E).
Prominent psychologists mentored by Kurt Lewin included Leon Festinger (1919 - 1989), who became known for his cognitive dissonance theory (1956), environmental psychologist Roger Barker, Bluma Zeigarnik, and Morton Deutsch, the founder of modern conflict resolution theory and practice.
Force field analysis provides a framework for looking at the factors (forces) that influence a situation, originally social situations. It looks at forces that are either driving movement toward a goal (helping forces) or blocking movement toward a goal (hindering forces). The principle, developed by Kurt Lewin, is a significant contribution to the fields of social science, psychology, social psychology, organizational development, process management, and change management.
Lewin, then a professor at MIT, first coined the term “action research” in about 1944, and it appears in his 1946 paper “Action Research and Minority Problems”. In that paper, he described action research as “a comparative research on the conditions and effects of various forms of social action and research leading to social action” that uses “a spiral of steps, each of which is composed of a circle of planning, action, and fact-finding about the result of the action”.
Lewin often characterized organizational management styles and cultures in terms of leadership climates defined by  (1) authoritarian, (2) democratic and (3) laissez-faire work environments. Authoritarian environments are characterized where the leader determines policy with techniques and steps for work tasks dictated by the leader in the division of labor. The leader is not necessarily hostile but is aloof from participation in work and commonly offers personal praise and criticism for the work done. Democratic climates are characterized where policy is determined through collective processes with decisions assisted by the leader. Before accomplishing tasks, perspectives are gained from group discussion and technical advice from a leader. Members are given choices and collectively decide the division of labor. Praise and criticism in such an environment are objective, fact minded and given by a group member without necessarily having participated extensively in the actual work. Laissez faire environments give freedom to the group for policy determination without any participation from the leader. The leader remains uninvolved in work decisions unless asked, does not participate in the division of labor, and very infrequently gives praise. (Miner 2005: 39-40) 
An early model of change developed by Lewin described change as a three-stage process. The first stage he called "unfreezing". It involved overcoming inertia and dismantling the existing "mind set". Defense mechanisms have to be bypassed. In the second stage the change occurs. This is typically a period of confusion and transition. We are aware that the old ways are being challenged but we do not have a clear picture as to what we are replacing them with yet. The third and final stage he called "freezing". The new mindset is crystallizing and one's comfort level is returning to previous levels. This is often misquoted as "refreezing" (see Lewin K (1947) Frontiers in Group Dynamics).
The equation is the psychologist's most well known formula in social psychology, of which Lewin was a modern pioneer. When first presented in Lewin's book Principles of Topological Psychology, published in 1936, it contradicted most popular theories in that it gave importance to a person's momentary situation in understanding his or her behavior, rather than relying entirely on the past.