In a series of four experiments, behavioral scientists at the University of Chicago Booth School of Business and the Wisconsin School of Business tested students’ willingness to expose themselves to aversive stimuli in an effort to satisfy curiosity. For one trial, each participant was shown a pile of pens that the researcher claimed were from a previous experiment. The twist? Half of the pens would deliver an electric shock when clicked.

Twenty-seven students were told which pens were rigged; another 27 were told only that some were electrified. When left alone in the room, the students who did not know which ones would shock them clicked more pens and incurred more jolts than the students who knew what would happen. Subsequent experiments replicated this effect with other stimuli, such as the sound of fingernails on a chalkboard and photographs of repulsive insects.