Stanford prison study
a controversial 1971 study of the psychological effects of coercive situations, conducted by a research team under the direction of U.S. psychologist Philip G. Zimbardo (1933– ). The male participants were randomly assigned to the roles of either prisoner or guard in a simulated prison at Stanford University. A variety of methods and situations were used to depersonalize participants, diminish their sense of identity, and increase a sense of power on the one hand (guards) and powerlessness on the other (prisoners). The experiment was terminated after only 6 days of the originally scheduled 14, when several participants showed physical manifestations of stress and psychological trauma. The study was criticized on both ethical and methodological grounds but is often cited as an example of the power of the situation, because it illustrated the manner in which social contexts can influence and transform human behavior, often in very negative
ways. See also Lucifer effect.