<P> Eventually, Zimbardo became involved with the defense team of lawyers representing one of the Abu Ghraib prison guards, Staff Sergeant Ivan "Chip" Frederick . He was granted full access to all investigation and background reports, and testified as an expert witness in SSG Frederick's court martial, which resulted in an eight - year prison sentence for Frederick in October 2004 . </P> <P> Zimbardo drew from his participation in the Frederick case to write the book The Lucifer Effect: Understanding How Good People Turn Evil, published by Random House in 2007, which deals with the striking similarities between his own Stanford Prison Experiment and the Abu Ghraib abuses . </P> <P> The experiment was perceived by many to involve questionable ethics, the most serious concern being that it was continued even after participants expressed their desire to withdraw . Despite the fact that participants were told they had the right to leave at any time, Zimbardo did not allow this during the experiment . Zimbardo was faced with the ethical dilemma that the experiment could possibly return outstanding results if continued, but it might also adversely affect the participants' well - being if not halted . </P> <P> Since the time of the Stanford experiment, ethical guidelines have been established for experiments involving human subjects . The Stanford Prison Experiment led to the implementation of rules to preclude any harmful treatment of participants . Before they are implemented, human studies must now be reviewed and found by an institutional review board (US) or ethics committee (UK) to be in accordance with ethical guidelines set by the American Psychological Association . These guidelines involve consideration of whether the potential benefit for science outweighs the possible risk for physical and psychological harm . </P>

Who is most closely associated with the conformity experiment