For an experiment, psychologist Philip Zimbardo abandoned a car in two different neighbourhoods " one a crime-ridden inner city block, the other a prosperous suburb. In the first, almost everything was within hours stripped from the car in broad daylight; in the second, it was left untouched.
It isn't the local residents, Zimbardo says, who deserve credit for their honesty, or blame for their cupidity: it is the situations they found themselves in.
"Although you probably think of yourself as having a consistent personality across time and space," he says, "that is likely not to be true. You are not the same person working alone as you are in a group; in a romantic setting versus an educational one; when you are with close friends or in an anonymous crowd; or when you are travelling abroad as when at home base."
In The Lucifer Effect Zimbardo assembles disturbing evidence that any one of us, if subjected to the right situational forces, is capable of deliberately harming other people.
Would you ever torture anybody? In 1971, Zimbardo took 20 university students from California, divided them randomly into ten guards and ten prisoners and made them act out their respective roles. Some guards turned into bullying sadists; some prisoners suffered severe mental distress.
The professor himself watched these events with benign indifference until a fellow researcher (his girlfriend as it happens) confronted him: "what you are doing to those boys is a terrible thing".
Only then did he call a halt and consider how it was that his own ethical sense failed to restrain him from supervising these cruelties.
It was this Stanford Prison Experiment that qualified Zimbardo to give evidence when an American guard, who had taken part in the torture of Iraqi prisoners at Baghdad's Abu Ghraib Prison, was sentenced.
In 2004 digital photographs of the victims, naked, simulating sexual acts, on leashes and in other degrading postures, made world headlines.
The man in the dock " who was given eight years' jail " had been a well-raised, church-going, decorated soldier with no apparent predisposition to depravity. What prompted an apparently normal person to do such things, Zimbardo asked.
The wickedest men have often struck observers as all too ordinary. It was for Adolf Eichmann, the Nazi commandant of Auschwitz, that Hannah Arendt coined the term " "the banality of evil'. Half a dozen psychiatrists had certified him as "normal' " "more normal, at any rate, than I am after having examined him", one of them is said to have explained.
So is "society to blame" in the words of the well-worn cliche? Zimbardo thinks not. Without acquitting the actors themselves of responsibility, he locates the ultimate culprits at the very top " in the case of Abu Ghraib, he accuses the US Secretary for Defence, Donald Rumsfeld and President George W Bush of creating the situational forces which enabled the abuse to occur. He mentions the "redefining" of torture, restrictions on civil liberty in the name of national security, the "extraordinary rendition" of suspects and other tactics in the "War on Terror' which have blurred the distinction between right and wrong.
Without disputing any of this, you want to ask " where does it all end? Who or what is responsible for the situational forces to which politicians, or indeed academic researchers, are subject? Are not the experiments Zimbardo describes, themselves instances in which well-meaning men have caused others to suffer?
Christians would answer that it ends at the beginning: that the original "situational forces" are those brought about in the Garden of Eden when mankind was first tempted to disobey God. The book's title The Lucifer Effect, as its preface explains, is named for that tempter; but otherwise Zimbardo does not cite Scripture or consider its claims.
The reality of original sin is not altogether palatable to contemporary public opinion. When we read of a horrible crime or a cruelty, we like to suppose that the perpetrators are fundamentally different from you and me. Our justice system is predicated on this comforting notion " that some people have a personal disposition to evil which can be corrected or restrained; and others don't.
Zimbardo will have none of this. For each instance of human evil he describes he invites the reader to ponder: "me too?"
Well ought we to thank God for giving us a democratic, law-abiding, prosperous country to live in; for what if any of us had been a Hutu in 1990s Rwanda? Or a German in 1940s Poland?
No recent book has prompted me to such self-examination. For anyone who seeks to understand or teach others about the "how' of human sinfulness, The Lucifer Effect is crucial reading.
