The Stanford Prison Experiment has continued to raise questions about social science research ethics. Male student volunteers were randomly assigned to be prisoners or guards in a simulation in which the guards became sadistic and the prisoners showed extreme stress. Two ethical issues are the ability of the participants to leave the experiment and the failure to provide adequate oversight and intervening to limit the abuse of the prisoners. In 2018, these issues were revisited and some declared the experiment unscientific and untrustworthy. However, the experiment was carried out before many social science research ethics were established. A detailed description of the experiment reveals insights on how group dynamics and social structure can encourage normal individuals to harm one another in a prison environment. The study is a cautionary tale that should be included in textbooks to improve social science research, demonstrate the need for research ethics, and prevent outrageous treatment of prisoners in the real world.