In the early 1960s, researchers found that everyday people were willing to administer vicious electric shocks to others, if told to do so by an authority figure.
The Yale University study, known as the Milgram experiment, has now been replicated by researchers in Poland - with disturbingly similar results.
"Upon learning about Milgram's experiments, a vast majority of people claim that 'I would never behave in such a manner,' said social psychologist Tomasz Grzyb, who was involved in the research.
"Our study has, yet again, illustrated the tremendous power of the situation the subjects are confronted with and how easily they can agree to things which they find unpleasant."
In the original experiment, volunteers would find themselves being told to deliver increasingly strong electric shocks to a person in another room, whom they could hear screaming in pain and banging on the wall. Two-thirds of the volunteers were willing to deliver fatal 450-volt shocks when asked.
They didn't know it at the time, but the person receiving the shocks was an actor, and never in any danger.
The study was conducted in 1961, during the trial of Nazi war criminal Adolf Eichmann. Psychologist Stanley Milgram, for whom the study is named, wanted to know if the excuse many used - that they were just following orders - could be taken seriously.
For ethical reasons the new Polish research didn't ask volunteers to deliver definitively fatal shocks, but found 90 percent were willing to deliver the strongest on offer - 150 volts. All but one of the 80 volunteers said they believed they were delivering "painful" punishments.
Only men were used in the Milgram experiment, while the new study had an even mix of men and women. Volunteers, regardless of their sex, were three times more likely to stop shocking females than males.
The other main difference between the new study and the Milgram experiment which could account for the higher rate of obedience is the lack of screaming.
"We spared participants the intense anxiety that Milgram's participants experienced," said Jerry Burger, who has led similar studies.
"Because of ethical concerns, a complete replication of Milgram's work has been out-of-bounds for decades."
But the conclusions are always the same.
"The lesson is that under the right circumstances, each of us may be capable of engaging in uncharacteristic and sometimes very disturbing acts."