The 1962 Milgram Experiment (Full Documentary)

The Milgram experiment(s) on obedience to authority figures was a series of social psychology experiments conducted by Yale University psychologist Stanley Milgram. ... The experiment found, unexpectedly, that a very high proportion of subjects would fully obey the instructions, albeit reluctantly.
The Milgram experiment was carried out many times whereby Milgram (1965) varied the basic procedure (changed the IV). By doing this Milgram could identify which factors affected obedience (the DV). Obedience was measured by how many participants shocked to the maximum 450 volts (65% in the original study).

Milgram's Experiments and the Perils of Obedience
https://www.verywellmind.com/the-milgram-obedience-experiment-2795243