In what year was the developer of the psychological theory "Field theory" born?
Field theory (psychology):  It was developed by Kurt Lewin, a Gestalt psychologist, in the 1940s. Kurt Lewin: Kurt Lewin (September 9, 1890 – February 12, 1947) was a German-American psychologist, known as one of the modern pioneers of social, organizational, and applied psychology in the United States.
1890