Revisiting a Disturbing Study of Human Psychology Reveals Our Willingness to Obey and to Inflict Pain

The shock generator used by psychologist Jerry Burger in his replication of Stanley Milgram's original study. The machine is closely modeled after the one used by Milgram. Jerry Burger/Santa Clara University

In 1961, while Adolf Eichmann stood trial for Nazi war crimes, Yale University psychologist Stanley Milgram began what would become one of the most important—and disturbing—psychological experiments on record. Milgram recruited men of various educational and professional backgrounds in order to study their willingness to administer painful electric shocks to fellow human beings. More specifically, he was examining obedience to authority in the wake of the Holocaust: Milgram was trying to understand how and why so many people could be led to commit even seemingly horrific acts. His results revealed the disturbing extent to which people obeyed authority even when it meant knowingly inflicting pain.

Now, a new study confirms people today are just as willing as they were then to follow orders that cause pain to others.

Related: Science inches closer to a universal blood test for cancer

Milgram's design was simple: In the basement of a Yale campus building, the study participant was assigned to act as teacher for what he perceived to be a single student. The experimenter gave the "teacher" a set of words that were each followed by four possible pairings. Every time the "student" selected the wrong pairing, the experimenter instructed the teacher to push a button delivering an electric shock as punishment. The teacher was aware that the shocks began at 15 volts and increased with each wrong answer, all the way to 450 volts.

The study participants believed that the students were also newly recruited—they were actually in cahoots with the experimenter—and that the electric shocks were real (they were not). Every time the student chose a wrong answer, the experimenter told the teacher to administer a shock. As the voltage increased, so did the student's screams in what appeared to be response to pain. If the teacher hesitated to deliver the shock, the experimenter—the authority figure—would tell him to proceed. "Please continue," the experimenter would say. "It is absolutely essential that you continue." Or sometimes: "You have no other choice. You must go on."

And go on they did: In Milgram's first set of studies, 26 out of 40 participants continued to shock the students with each wrong answer, all the way to 450 volts. Even when the students pleaded for the shocks to end (starting at 150 volts), and even though the participant was absolutely convinced he was forcing an excruciating amount of electricity upon the learner, the participant more often than not continued.

The research revealed the extent to which our sense of obedience compels us to follow authority, even when it causes pain. Milgram's research became a landmark finding, haunting psychologists, along with most who read about the experiments, for decades to come. Over the years, several researchers replicated Milgram's work and confirmed his conclusions.

Now, a team of social psychologists in Poland has done so again. And it seems humans are as obedient as ever.

About two years ago, researchers at the University of Social Sciences and Humanities in Wroclaw wondered how current residents of Poland would fare in a Milgram-style study. Their interest was piqued in part by the recent surge of a political party called Law and Justice. "This party values governing with a strong hand rather than freedom and democracy," the authors write in their study, published in Social Psychological and Personality Science. The authors also realized that Milgram's work, though replicated many times, had never been examined specifically in central Europe. In light of the country's history—the Communist system was forced upon Poland following World War II—and the current political climate, the researchers thought Milgram's experiment could provide useful insights into the mindset of Polish citizens.

After being recruited off the street and by university students, participants were offered about $15 to join a study on memory and learning. The recruits were told that the study would examine the impact of punishment on learning, and that they could cease participation at any time.

The study followed the same pattern as Milgram's. The students—actors, really—were given a pairing test. With each incorrect response, the participant teachers were told to deliver a shock, starting with 15 volts and increasing incrementally to 150 volts. (This adjustment—halting the study at 150 volts—was first integrated into the experiment by Jerry Burger, who researches psychology at Santa Clara University, in his replication of Milgram's work. "We spared participants the intense anxiety that Milgram's participants experienced," says Burger.)

The experimenter issued the same authority-figure directives that Milgram used. To confirm that the participants knew what they were doing, the experimenter asked after reaching the 10th voltage increment or if a participant refused to proceed: "Do you think it hurts?" All but one of the 80 participants confirmed that they believed they were delivering painful shocks.

Nearly all of the study recruits—90 percent of them—proceeded through to the highest shock level.

Burger notes that the higher rate of compliance than in the Milgram study could be because the Polish experiment didn't include the students screaming. "Because of ethical concerns, a complete replication of Milgram's work has been out-of-bounds for decades," says Burger. Still, he says, the study helps dismiss the notion that the obedience Milgram witnessed was tied to the era and location of his work. "The lesson," he says, "is that under the right circumstances, each of us may be capable of engaging in uncharacteristic and sometimes very disturbing acts."

The Polish researchers also hoped to determine whether the recruits would behave differently based on the student's gender. Would they issue fewer shocks if the learner was female? They found that the participants were three times more likely to stop shocking female students, regardless of their own gender (unlike with Milgram, who used only men, female participants were also recruited by the Poland researchers). But they note that considering the very high number of recruits who followed all of the experimenter's orders, the gender data were not very meaningful.

What is meaningful is that even though more than 50 years have passed since Milgram's first studies, the experiment demonstrates obedience to authority is still extremely high. "Exceptionally fascinating" is how the authors describe the results.

Burger says people always insist they would have stopped early in the process if recruited to participate in the experiment. "Yet we've done the studies," he says. "We know what most people would do."