In 1971, Philip Zimbardo, then a lecturer at Stanford University conducted an experiment using student volunteers. The volunteers were placed into two groups of prisoners and guards. They were then taken to a make shift prison within the University remises where they were given two weeks for the experiments. The guards were given control over the inmates, where they set their own rules on how to govern the prisoner population.
While the first day passed without incident, the preceding days brought with them problems. Despite being fairly normal people, the guards started living their roles, and taking advantage of the power they had been bestowed. This they did by not only working the way guards in a normal prison would, but going further as to mistreat the prisoners under their care. Similarly, the prisoners acted out their roles by becoming depressed and withdrawn. In fact, the situation got so bad as to lead to the termination of the experiment after only six days. The experiment implies that good, ordinary people can do the most horrific things if their surroundings allow them to, and they are expected to do so by others.