On April 15th, 1964, the New York Times reported that in Albany, New York, a crowd of 4,000 people chanted, "Jump! Jump! Jump!" as a suicidal teenager stood on a 12th story hotel ledge. The teenager had been under psychiatric care at the Albany Medical Center, and apparently nobody knew how he got out on that ledge. But as the crowd grew, people started to shout things like, "Aw, c'mon, you're chicken!" "Jump! What's the matter, you yellow?" One woman complained to her friend, "I wish he'd do it and get it over with. If he doesn't hurry up, we're going to miss our last bus." People even started betting on whether he would jump. Now, what would cause people to behave this way? This is an example of what psychologists call "deindividuation"— a phenomenon first discussed in a 1952 article by Leon Festinger, Al Pepitone, and Ted Newcomb. According to Festinger and his associates, deindividuation occurs when individuals are not seen or paid attention to as individuals. The members do not feel that they stand out as individuals, and there's a reduction of inner restraints against doing various things. What are the things? Well, on the positive side they might be uninhibited dancing, singing, or performing without feeling self-conscious. But there's also a darker side of deindividuation that can lead to lynchings, gang rapes, riots, stealing, cheating— things that violate norms of restraint that most of us rely on in daily life. Well, Festinger's paper was interesting, but psychologists didn't really do much with the idea of deindividuation until about 1970, when Phil Zimbardo published a monograph entitled "The Human Choice: Individuation, Reason, and Order Versus Deindividuation, Impulse, and Chaos." In this paper, Zimbardo listed a number of input variables or antecedent conditions that increase the chances of deindividuation: anonymity, diffused responsibility (in which individuals aren't held personally accountable for their behavior), group size and group activity, physical and mental arousal, an altered time perspective (in which the present is emphasized and the past and future seem distant), sensory input overload (or a state of overstimulation), physical involvement in the act, and altered states of consciousness (as a result of drugs, alcohol—even certain sleep patterns). Zimbardo proposed that, when taken together, these factors can lead to deindividuation—a state in which behavior's relatively unrestrained, wild, and sometimes potentially violent. Since the time that Zimbardo proposed his theory, dozens of laboratory and field studies have looked at deindividuation, running the full range from very mild cases all the way up to extreme cases of deindividuation. And even though the results are mixed and the effect isn't always strong, a 1998 meta-analysis of 60 independent studies concluded that, in the main, one key aspect of Zimbardo's theory is correct, and that is that larger groups either induce or facilitate stronger anti-normative behavior—that is, behavior that violates social norms. Moreover, the meta-analysis didn't find significant gender differences in response to deindividuating situations. Women were just as likely as men to violate norms when the setting promoted deindividuation, so this isn't simply a male thing. More recently, the role of group size in Zimbardo's model was supported by a study that looked at 60 cases in which an African American was killed by a lynch mob in the United States, events that occurred between 1899 and 1946. What this study found is that lynchings tended to become more vicious as the size of the mob grew—that is, more likely to involve atrocities, like burning or mutilating the victim. To take a notorious example (and I should warn you up front that the next minute of material is extremely disturbing, so you might want to fast forward), here is the mob that lynched 17-year-old Jessie Washington in Waco, Texas, on May 15th, 1916. The lynching took place on the City Hall lawn, and there were over 10,000 people present, including the mayor, chief of police, and children. You can see Washington here at the base of a tree. Kind of hard to make out, but there he is. During the event—which later became known, by the way, as the Waco Horror— members of the mob castrated Washington, cut off his fingers and toes, and hung him over a bonfire, lowering and raising him over the fire for about two hours. Hard to even imagine— absolutely barbaric behavior fueled by a mob mentality, an extreme case of deindividuation. On a much more mild note, a 2010 laboratory study suggested that even the feeling of anonymity might be enough to deindividuate people. In one of the reported experiments, participants in a room with slightly dimmed lighting cheated more than participants in a well-lit room. People in the dimmed room were just told some of the lights were out. And in a second experiment, which involved a two person computer game, participants wearing sunglasses behaved more selfishly than participants wearing clear glasses, even though there was no face-to-face interaction in which sunglasses would have even been visible to the other person. What's interesting is that in both experiments, people's anonymity didn't actually change. They simply felt more anonymous. Well, as I mentioned earlier in the course, Professor Zimbardo has kindly agreed to share with our class his documentary Quiet Rage, a documentary that shows one of the most dramatic demonstrations of what can happen when people become deindividuated— when they become engulfed in a role and lose their sense of personal identity or responsibility. The video discusses a very famous study in social psychology called the "Stanford Prison Experiment," which was conducted by Phil Zimbardo over 40 years ago. And here you can see one of the guards wearing sunglasses. So please watch Quiet Rage and then come back for part two of our discussion about deindividuation. But first, a pop up question.