I summarize more than 30 years of research on factors that can create a "perfect storm" which leads good people to engage in evil actions. This trans… - Philip Zimbardo

The “Lucifer Effect” describes the point in time when an ordinary, normal person first crosses the boundary between good and evil to engage in an evil action. It represents a transformation of human character that is significant in its consequences. Such transformations are more likely to occur in novel settings, in “total situations,” where social situational forces are sufficiently powerful to overwhelm, or set aside temporally, personal attributes of morality, compassion, or sense of justice and fair play.

Whether we consider Nazi Germany or Abu Ghraib prison, there were many people who observed what was happening and said nothing. At Abu Ghraib, one photo shows two soldiers smiling before a pyramid of naked prisoners while a dozen other soldiers stand around watching passively. If you observe such abuses and don’t say, “This is wrong! Stop it!” you give tacit approval to continue. You are part of the silent majority that makes evil deeds more acceptable.

The idea of the banality of heroism debunks the myth of the “heroic elect,” a myth that reinforces two basic human tendencies. The first is to ascribe very rare personal characteristics to people who do something special — to see them as superhuman, practically beyond comparison to the rest of us. The second is the trap of inaction — sometimes known as the "bystander effect." Research has shown that the bystander effect is often motivated by diffusion of responsibility, when different people witnessing an emergency all assume someone else will help. Like the “good guards,” we fall into the trap of inaction when we assume it’s someone else’s responsibility to act the hero.