Stanford University professor Philip Zimbardo described a "Lucifer effect" as he flashed shocking images of Abu Ghraib horrors for those at an elite Technology, Entertainment and Design conference in California.
"If you give people power without oversight it is a formula for abuse," Zimbardo said to a stunned audience the included famous actors, entrepreneurs and politicians.
"Abu Ghraib abuses went on for three months ... Who was watching the store? Nobody, and it was on purpose."
Zimbardo, 75, is renowned for the 1971 Stanford prison experiment in which students on summer break play roles as guards or prisoners in a mock prison in the basement of a building on the university's campus in Northern California.
The pretend guards grew so sadistic and the prisoners so cowed that the experiment was halted prematurely out of concern for the students.
Zimbardo detailed stark parallels to abuses of suspected terrorists by US soldiers at Abu Graib prison in Iraq, and how environment can turn people into heroes or demons.
"I was shocked when I saw those pictures but I wasn't surprised," Zimbardo said of the images he was privy to while a member of a legal defense team for a sergeant charged in connection with prison abuses.
"Because I had seen those cells before at Stanford. The power is in the system. It's not bad apples, but bad barrel makers."
Zimbardo, wearing a black T-shirt with a picture of a devil flanked by two angels, paced the stage as images of horrors flashed on large screens. He lays out his conclusions in a recently released book titled "The Lucifer Effect."
"There is an infinite capacity to make us behave kind or cruel, or make some of us heroes," Zimbardo said, convinced that environment dictates the outcome far more than people's characters or personalities.
"The Stanford prison experiment shows the power of institutions to change behavior. We took good apples and put them in a bad situation."
As a witness for a US military police reservist that was a guard at the Abu Ghraib interrogation center when abuses occurred, Zimbardo got access to records and pictures gathered in the case.
The guards were told to "soften" prisoners to make them more cooperative with military intelligence interrogators, according to Zimbardo.
Photos showed naked and hooded prisoners beaten bloody and being made to commit humiliating acts such as human pyramids or simulating homosexual sex. Soldiers posed proudly with battered corpses and nude, injured prisoners.
A picture shows a soldier firing a bullet into a camel's head at point blank range.
"They took pictures of everything," Zimbardo said.
A "hero" at Abu Ghraib turned out to be a lowly private that called for abuses there to be stopped, according to the professor.
"Heroism is the antidote to evil," Zimbardo said. "Let's focus on justice and peace, which sadly our administration has not been doing."
© 2008 Agence France Presse