I liked your reasoning behind the ethics of the Zambardo experiment. I would say that on paper, the design of the experiment is completely ethical; but only with the assumption that the scientists and Zambardo would leave them unharmed. The participants were young, and this is key. They are used to obedience and usually follow subordinance — especially during a top experiment at Stanford University. Thus, while they agreed to a “mock prison” study, it can be inferred most did not agree to “psychological breakdowns/distress”, or witnessing the normalcy of their peers dissolve into a corrupt dehumanization of others. Unfortunately, questionably ethical studies tend to uncover truths more efficiently, I firmly believe that science should remain ethical under strict guidelines and regulatory agencies.