Kurt Lewin 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.

Social psychology is the scientific study of how thoughts, feelings, and behaviors are influenced by the actual, imagined, or implied presence of others. Social psychologists typically explain human behavior as a result of the relationship between mental states and social situations, studying the social conditions under which thoughts, feelings, and behaviors occur, and how these variables influence social interactions.