>Next, participants received our standard instructions to entertain themselves with their thoughts (in this case for 15 min). If they wanted, they learned, they could receive an electric shock again during the thinking period by pressing a button. We went to some length to explain that the primary goal was to entertain themselves with their thoughts and that the decision to receive a shock was entirely up to them. Many participants elected to receive negative stimulation over no stimulation—especially men: 67% of men (12 of 18) gave themselves at least one shock during the thinking period [range = 0 to 4 shocks, mean (M) = 1.47, SD = 1.46, not including one outlier who administered 190 shocks to himself], compared to 25% of women (6 of 24; range = 0 to 9 shocks, M = 1.00, SD = 2.32).
You can read the complete study here, https://wjh-www.harvard.edu/~dtg/WILSON%20ET%20AL%202014.pdf
I´m quite intrigued about the outlier who managed to shock himself every 4.7 seconds for 15 minutes straight. Was he trying to go for a record or just plain masochism...