"How we went about testing these questions and what we found may astound you. Our planned two-week investigation into the psychology of prison life had to be ended after only six days because of what the situation was doing to the college students who participated. In only a few days, our guards became sadistic and our prisoners became depressed and showed signs of extreme stress. Please read the story of what happened and what it tells us about the nature of human nature."

–Professor Philip G. Zimbardo