Zimbardo's prison experiment shows us that most people have cruel intentions toward other individuals people are willing to be obedient to false authority truly normal people won't act horribly if placed in evil situations it's possible for people to act horribly in evil situations

I believe the answer is: people are willing to be obedient to false authority

In the experiment, subjects are divided into two roles, prisoners and guards.
After that, they're told to behave according to their roles.
As it turned out, the result shows that they take their roles really seriously even if they are aware that their roles are fakes