Kurt_Lewin

Kurt Lewin ( lə-VEEN; 9 September 1891 – 12 February 1947) was a German-American psychologist, known as one of the modern pioneers of social, organizational, and applied psychology in the United States. During his professional career Lewin applied himself to three general topics: applied research, action research, and group communication.
Lewin is often recognized as the "founder of social psychology" and was one of the first to study group dynamics and organizational development. A Review of General Psychology survey, published in 2002, ranked Lewin as the 18th-most cited psychologist of the 20th century.