"If you give people power without oversight it is a formula for abuse," said Philip Zimbardo, professor at Stanford University.

Professor Zimbardo was delivering a presentation at the Technology, Entertainment, and Design conference in California.

He believes that a badly concieved environment is capable of turning someone who has been well behaved into a sadistic torturer.

"Abu Ghraib abuses went on for three months."

"Who was watching the store?"

"Nobody, and it was on purpose."

Zimbardo came to prominence in 1971, with the Stanford prison experiment -- students were divided into two groups consisting of prisoners and guards to study how their behaviour was dictated by their role.

The pretend guards grew so sadistic and the prisoners so cowed that the experiment was stopped prematurely as there was a serious risk of injury.

Zimbardo was approached in 2004 to assist in the defence of a soldier under investigation for abuses at Abu Ghraib.

This gave him the opportunity to see previously confidential photographs detailing the acts of torture committed there.

"I was shocked when I saw those pictures but I wasn't surprised."

"Because I had seen those cells before at Stanford."

"The power is in the system."

"It's not bad apples, but bad barrel makers."

"There is an infinite capacity to make us behave kind or cruel, or make some of us heroes."

"The Stanford prison experiment shows the power of institutions to change behaviour."

"We took good apples and put them in a bad situation."

Professor Zimbardo was inspired by his work on the Abu Ghraib case to write a new book entitled 'The Lucifer Effect', where he analyses just how and why good people can be dehumanised to the point where they are capable of evil.

He also suggests that 'heroism is the antidote to evil' -- while superheroes make for unrealistic role models, the soldier that blew the whistle on abuses at Abu Ghraib was the kind of hero that society needs to be encouraging.

"Let's focus on justice and peace, which sadly our administration has not been doing."