On August 15, 1971, police officers arrived at homes around Palo Alto, California, and arrested several college students . The young men were searched, handcuffed, and taken to a police station. Then, they were blindfolded and driven to a makeshift jail in the basement of Stanford University’s psychology building.

None of them had committed a crime. They had actually answered an advertisement for a “psychological study of prison life” run by Stanford professor Philip Zimbardo. The experiment was supposed to continue for up to two weeks but only lasted six days.

Netflix’s new unscripted series, The New Stanford Prison Experiment , returns to the question behind the original study: What happens when ordinary people are suddenly given power over others?

Here’s what to know about the real Stanford Prison Experiment and why it ended so quickly.

Zimbardo, a 38-year-old social psychologist, wanted to study how the prison environment affected the people living and working inside one.…