The SPE is a bad, almost unscientific example for nearly anything.
In 2007, Thomas Carnahan and Sam McFarland argued that the experiment suffers from selection bias, as the recruiting posters for SPE specifically advertised participation in a study about prison life. Carnahan and McFarland argued that those who applied to participate with the SPE thus likely already had traits associated with abusiveness, aggression, authoritarianism, Machiavellianism, social dominance orientation, and narcissism. Further, low dispositional empathy and altruism would also be indicators of someone who would volunteer.
In 2020, Dutch historian Rutger Bregman claimed the experiment to be dubious. He states that the guards were urged to act aggressively towards the prisoners. In his book Humankind: A Hopeful History, he is of the opinion that in similar experiments, researchers intentionally created hostility between groups and then interpreted the findings to suit their needs.
Just give it some time, anyone with power becomes a Nazi. Just ask the Stanford Prison Experiment folks.
The SPE is a bad, almost unscientific example for nearly anything.
Wiki
The SPE was closer to performance art than to legitimate research.