Changing or preventing undesirable behavior of individuals or groups requires an understanding of what strengths, virtues and vulnerabilities they bring into given situation. Then we need to recognize more fully the complex of situational forces that are operative in given behavioral settings. Modifying them, or learning to avoid them, can have a greater impact on reducing undesirable individual reactions than remedial actions directed only at changing the people in the situation. That means adopting a public health approach in place of the standard medical model approach to curing individual ills and wrongs. However, unless we become sensitive to the real power of the System, which is invariably hidden behind a veil of secrecy, and fully understand its own set of rules and regulations, behavioral change will be transient and situational change illusory. Throughout this book, I repeat the mantra that attempting to understand the situational and systemic contributions to any individual’s behavior does not excuse the person or absolve him or her from responsibility in engaging in immoral, illegal or evil deeds.

Zimbardo, prefacio a «El efecto Lucifer», a propósito de este post.