1935 Muzafer Sherif demonstrates how groups quickly come to develop a “social norm” in his autokinetic effect experiments.
1940s Kurt Lewin shows how people’s behavior changes as their situations are altered.
1963 Stanley Milgram conducts his obedience studies, which demonstrate that people will obey authority even if it means committing cruel acts.
2002 British psychologists Steven Reicher and Alex Haslam extend Zimbardo’s study to explore positive rather than negative group behavior.
2004 Zimbardo defends a former Abu Ghraib prison guard in court, arguing that the circumstances caused the guard’s cruel behavior. ...