In one classic study,35 male volunteers from the Indiana University community were subjected to arguably more intense stressors than overcrowding in a cage: They were made to watch a digital clock countdown from 360 to 0, at which point they would receive a painful electric shock or have to give an extemporaneous speech, into a camera, on the topic, “What I like and dislike about my physical appearance.” This speech would then be rated by a panel of judges for degree of openness and level of neuroticism. (Human subject approval was apparently much easier to get in the 1980s.)
