The Stanford Prison Experiment had major ethical issues, but it did result in Zimbardo testifying to congress that what happened at Abu Ghraib prison was not a “bad apples” situation, but the inevitable result of putting a bunch of soldiers in charge of a prison with no real rules.

A quote from his book The Lucifer Effect (I haven’t read it, I got this from Wikipedia when I looked him up to see if I could get a quote from him talking to congress, which I couldn’t.):

“Good people can be induced, seduced, and initiated into behaving in evil ways. They can also be led to act in irrational, stupid, self-destructive, antisocial, and mindless ways when they are immersed in ‘total situations’ that impact human nature in ways that challenge our sense of the stability and consistency of individual personality, of character, and of morality.”