Stanford University, 1971. One of history's most notorious psychology studies begins. The experiment simulated a prison environment and assigned students to the roles of guards and prisoners. Myths abound about what really happened but in this documentary series, participants take a seat in front of the camera to reveal never-before-heard details of what really happened, including the infamous hunger strike. Watch The Stanford Prison Experiment: Unlocking The Truth on Sunday 15th June at 9pm, on

At Stanford University in 1971, one of history's most notorious psychology studies took place. The experiment simulated a prison environment and assigned students to the roles of guards and prisoners. Hear from participants in this gripping documentary series, about what really happened. Watch The Stanford Prison Experiment: Unlocking The Truth on Sunday 15th June at 9pm, on #NationalGeographic UK. | National Geographic UK