The Lucifer Effect by Zimbardo, 2007, Excerpts
People can do terrible things when they allow the role they play to have rigid boundaries that circumscribe what is appropriate, expected, and reinforced in a given setting. Such rigidity in the role shuts off the traditional morality and values that govern their lives when they are in “normal mode.” To the extent that we can both live in the skin of a role and yet be able to separate ourselves from it when necessary, we are in a position to “explain away” our personal responsibility for the damage we cause by our role-based actions.
In addition to the power of rules and roles, situational forces mount in power with the introduction of uniforms, costumes, and masks, all disguises of one’s usual appearance that promote anonymity and reduce personal accountability. When people feel anonymous in a situation, as if no one is aware of their true identity, they can more easily be induced to behave in antisocial ways. This is especially so if the setting grants permission to enact one’s impulse or to follow orders or implied guidelines that one would usually disdain.
In the Stanford Prison Experiment, the power that the guards assumed each time they donned their military-style uniforms was matched by the powerlessness the prisoners felt when wearing their wrinkled smocks with ID numbers sewn on their fronts. The guards had billy-clubs, whistles, and sunglasses that disguised their eyes; the prisoners had a chained ankle and a stocking cap to contain their long hair. These situational differences were not inherent in the cloth or the hardware; rather, the source of their power is to be found in the psychological material that went into each group’s subjective constructions of the meaning of these uniforms.