The "teachers" in this recent experiment, conducted in 2006, also received several reminders that they could quit whenever they wanted, unlike in Milgram's study.

CNN: Charting the psychology of evil, decades after 'shock' experiment

The new results correlate well with Milgram's: 70 percent of the 40 participants were willing to continue after 150 volts, compared with 82.5 percent in Milgram's study -- a difference that is not statistically significant, Burger said.

CNN: Charting the psychology of evil, decades after 'shock' experiment

Still, some psychologists quoted in the same issue of American Psychologist questioned how comparable this study is to Milgram's, given the differences in methods.

CNN: Charting the psychology of evil, decades after 'shock' experiment

His study's design imitated Milgram's, even using the same scripts for the experimenter and suffering learner, but the key difference was that this experiment stopped at 150 volts -- when the learner starts asking to leave.

CNN: Charting the psychology of evil, decades after 'shock' experiment