Original result
26 of the 40 men, or 65%, went all the way to the last switch. The learner was actually an actor working with the researchers and the shocks were not real, but the participants did not know that.
What we know today
In 2009, Jerry Burger repeated the study within ethical limits by stopping it at 150 volts: 70% of participants were willing to go past 150 volts. Milgram’s figure at the same point was 82.5%, and the difference was not significant. On the other hand, researchers who went through Milgram’s archives found that experimenters sometimes departed from the script and that some participants suspected the shocks were fake. In Milgram’s own variations, obedience also changed a lot depending on the conditions.
The surprising part
Before the study, the psychiatrists Milgram asked predicted that only about one in a thousand people would go to the last switch.
Sources
- Milgram, S. (1963). Behavioral study of obedience. Journal of Abnormal and Social Psychology, 67(4), 371–378. doi.org/10.1037/h0040525
- Burger, J. M. (2009). Replicating Milgram: Would people still obey today? American Psychologist, 64(1), 1–11. doi.org/10.1037/a0010932