October 9, 2008 lecture by Philip Zimbardo during the 2008 Reunion Homecoming Classes Without Quizzes program. Why do good people turn evil? In what sense are evil and heroism comparable? How could the little old Stanford prison experiment reveal parallels and insights about the abuses by military guards at Abu Ghraib?Philip Zimbardo, professor of psychology, emeritus, is internationally recognized as a leading "voice and face of contemporary psychology" through his widely seen PBS-TV series, Discovering Psychology, his media appearances, best-selling trade books on shyness, and his classic research, The Stanford Prison Experiment.