Why do good people do bad things? In the 1960s, Stanley Milgram sought to answer this question by conducting a series of experiments, now collectively termed The Milgram Experiment, which has become one of psychology’s most infamous studies.

In a basement at Yale University, Milgrim had figures of authority order volunteers to administer electric shocks to actors who led the participants to believe the shocks were real by screaming and crying for mercy. Throughout the study, some participants stopped the experiment early against the experimenter’s orders, but 65 percent continued all the way through, administering shocks reaching 450 volts. The results suggested that people are willing to commit harmful acts when obeying authrority.

Five decades later, the Milgram Experiment would be considered unethical, and flaws in its research design have led some to question the study’s authenticity and reliability. New research, however, has added to Milgram’s work, and it suggests he was right. Researchers from University College London and Université Libre de Bruxelles in Belgium published a paper in Current Biology that claims people are willing to do bad things when following orders because following orders makes individuals feel less responsible for their actions.

"People often claim reduced responsibility because they were 'only obeying orders,’” said study author Patrick Haggard,” but are they just saying that to avoid punishment, or do orders really change the basic experience of responsibility?"

To answer this question, the researchers studied a psychology phenomenon called “sense of agency,” which is the feeling that one’s actions have caused an external event. Volunteers administered something harmful (either a mild electric shock or a small financial penalty), onto another group of volunteers. No actors were used in this study, and each group took turns at every roll, so each participant knew how the electric shocks felt. The study was also divided into two separate experiments, where one group of volunteers was specifically instructed to administer the harm, while the other was given the choice to do so, but incentivized with a financial reward.

The researchers found that the group who followed orders had less sense of agency than the group who made their own decisions, as well as reduced neural processions of the outcomes of their actions. On this basis, the researchers concluded that obeying orders diminishes one’s sense of responsibility, and claims of reduced responsibility are not just attempts to avoid social punishment.

Source: Caspar EA, Cleeremans CA, Haggard P. Coercion Changes the Sense of Agency in the Human Brain. Current Biology. 2016.