Following the almost unimaginable slaughter of WWII, scholars in many fields became preoccupied by the notion of conformity. How could so many otherwise ordinary people participate in the atrocities of the Holocaust? Can the pressure to conform be so powerful that it can account for such extreme behavior? Questions such as these spurred investigation into the behavior of groups. A good deal of research on the structure and behavior of groups has been performed within a branch of psychology known as social psychology. Social psychologists conducted research on group norms, group identity, and on conformity. One of the pioneers of group dynamics was a social psychologist named Kurt Lewin (1890-1947).