In our discussion of the bystander effect, we examined the role of bystanders in the murder of Kitty Genovese and the fatal assault on Deletha Word, but I didn't say much about the role of the perpetrators, or more generally, about the topic of violence. So in this video, I'd like to talk about the triggers of aggression— that is, the factors that could lead to anything from very small acts of aggression, all the way up to murder, or terrorism, or warfare. As defined in this week's reading, aggression is "physical or verbal behavior intended to cause harm." The act might involve hostile aggression, which springs from anger or hostility, or instrumental aggression, which also aims to harm, but mainly as a means to some other end. For instance, social psychologists would say that when the United States bombed Baghdad in order to overthrow Saddam Hussein, it was an act of instrumental aggression. And, of course, some acts may involve both hostile and instrumental components. Most social psychology research on aggression has to do with things that may or may not cause it, such as violent TV shows, hot weather, pornography, video games, and so on. For example, one of the oldest questions is whether watching violence on TV causes children to become aggressive, or whether it's merely correlated with aggression. Let's pause for a pop-up question so that you can predict what researchers have found, and then after, I'll share with you what the scientific consensus is. Although the debate over correlation versus causation ran for decades, by now there's overwhelming evidence that exposure to TV violence causes aggression, at least in some cases. As far back as 1972, the U.S. Surgeon General warned about "a causal relation between viewing violence on television and aggressive behavior." Then in 1982, a report by the National Institute of Mental Health supported this conclusion. And in 1985, the American Psychological Association passed a resolution informing broadcasters and the public that television violence poses a danger to children. In 2000, six of the top medical and health organizations in the United States signed a joint statement on the impact of entertainment violence on children, in which they wrote that "well over 1,000 studies point overwhelmingly to a causal connection between media violence and aggressive behavior." And in 2007, a landmark meta-analysis examined 24 research reports in which children or adults were exposed to media violence and the amount of naturally occurring aggression was later recorded or independently rated. In other words, these weren't artificial laboratory tasks related to aggression. The children simply played with each other, and adults interacted with one another, while trained observers recorded people's behavior. The results? Roughly one out of every four or five participants showed an increase in aggression, which was a highly significant result given the large number of studies, and of course, these are only brief exposures to violence. To put these results in context, the effect of media violence on aggression was stronger than the effects are of condom usage on HIV transmission. They were stronger than the effects of lead exposure on children's intelligence, and stronger than the effects of calcium intake on bone mass. So the relationship between media violence and aggression is substantial, it's causal, and the increase in aggression has been found in interactions among friends, among classmates, strangers, a wide variety of situations, and a wide variety of studies. In fact, in 2010, a study published in the Journal of Advertising even found a statistically significant increase in aggressive thoughts when kids watched a violent 30-second TV commercial for action figure toys. A toy commercial! Yet when the researchers held focus group sessions (open discussions with kids and with parents), neither the children nor the adults expressed concern about the violence in TV commercials. In those cases when parents limited the amount of media violence that their kids were allowed to see, the limits were always on TV shows, movies, or video games—never violence in the commercials. Now, why is TV so powerful? Well, over time, kids learn to imitate what they see on TV, and research suggests that later in childhood and in adulthood, those effects sometimes show up in the form of bullying other people, of partner violence, copycat crimes, and so on. Kids are unbelievably good at imitation learning, which I will illustrate with my own daughter, Fijare. By the time she was 15 months old, Fijare had seen enough people using cell phones that she began imitating. But as you can see from the bottom photos where she's talking into the back of the phone, she didn't have it quite right. By the time she was two and a half years old, however, she had not only figured it out—she looks like she's setting up a power lunch before going out to play in the snow. The tendency for kids to learn through imitation, and the link between children's imitation learning and aggression, was dramatically illustrated in a famous 1961 study by Albert Bandura and two coauthors in which children were mildly frustrated by the removal of some popular toys and then either were or were not exposed to an adult model who punched, kicked, and yelled at a plastic Bobo doll. What the study found was that kids who had earlier seen an aggressive model often ended up imitating the behavior and beating up the doll, whereas kids who hadn't been exposed to an aggressive model rarely showed aggression toward the doll. Now, you might be wondering, why is this research so famous? Isn't it obvious that kids will imitate what they see adults do? Well, we have to guard against hindsight bias here. Before Bandura's research, it was widely believed that a good way to reduce aggression was to just get it out of your system by, for example, punching a pillow or screaming— something like that— or watching somebody else behave aggressively on the athletic field, in the boxing ring, on TV or in a movie, and so forth. Here's an example from the days of vaudeville. The idea is to blow off steam, to vent in a kind of "catharsis"— an idea that Aristotle wrote about and that was later adapted by Sigmund Freud and others, as a sort of hydraulic model in which emotional pressures build and build until finally you release them by behaving aggressively or by watching other people do it for you, like we see here. Isn't that clip amazing? In the Snapshot Quiz, I asked whether you thought that punching a pillow or screaming might be an effective way to reduce aggression. If you answered yes, it may be in part due to a cultural legacy from Sigmund Freud. On the other hand if you said no, it may be a legacy from Albert Bandura. Let's pause so that you can see your answer. What Albert Bandura and others after him have shown is that contrary to the catharsis hypothesis, aggression begets aggression. So for example, if I punch the video camera lens, it's not going to make me feel less aggressive or improve my mood. In fact, here, we can try an experiment. [SOUND OF GLASS BREAKING] Nope. Don't feel less aggressive, don't feel any better. In fact, here, let me get rid of this. There we go. Returning to the Bobo doll study, Professor Bandura was kind enough to send along to our class a couple minutes of video footage from the original study, during which he makes a few remarks, and I'll add a few comments of my own. Let's watch. >> An adult model beat up an inflated Bobo doll in novel ways. She pummeled it with a mallet, flung it in the air, kicked it repeatedly, and threw it down and beat it. And these novel acts were embellished with hostile remarks. It was once widely believed that seeing others vent aggression would drain the viewer's aggressive drive. As you can see, exposure to aggressive modeling is hardly cathartic. Exposure to aggressive modeling increased attraction to guns, even though it was never modeled. Guns had less appeal to children who had no exposure to the aggressive modeling. The children also picked up the novel, hostile language. >> To see how much aggression there was, just look at the facial expression. And it wasn't only boys. Here you can see a girl using a mallet to viciously attack the doll. >> The room contained varied play materials, and children could choose to play aggressively or non-aggressively. >> Besides aggressive toys, like a mallet and dart guns, there were crayons and coloring paper, dolls, cars and trucks—lots of choices. >> The children devised new ways of hitting the doll. And here's a creative embellishment. A doll becomes a weapon of assault. >> By the way, two historical footnotes: First, a Bobo doll of the sort that Bandura used in his research is now on display at the Center for the History of Psychology— actually, just a few feet away from one of the doors of the Stanford Prison Experiment and the electric shock generator used by Stanley Milgram in his obedience research. Here are a few photos I took just to give you a close-up picture of what the doll looked like. And second, in 2004 Albert Bandura went on to receive the Outstanding Lifetime Contribution to Psychology Award from the American Psychological Association— not only for his research on aggression, but for research suggesting the positive side of imitation learning. Based on his research, for example, serial TV dramas have harnessed the power of imitation learning to promote positive social change. So, it's not all about aggression. Here are two examples. In Mexico, nearly a million people enrolled in a program to learn to read after watching a TV drama that promoted literacy by showing characters struggling to read and then becoming literate. And in Tanzania, a series of TV dramas led married people to discuss the need to control family size and to adopt family planning methods. But returning to the topic of aggression, one of the most important questions that grew out of Bandura's research is whether behaviors modeled on television show the same sort of effect that he documented in the laboratory. For instance, when there's a widely publicized boxing match, does the level of aggression in society go up? In one of the most famous boxing matches in history, Muhammad Ali against Joe Frazier, Muhammad Ali actually took out a little gorilla doll and punched it during a press conference, pretending that the doll was Joe Frazier (somewhat similar to a little Bobo doll). >> Come on, Gorilla. We in Manila. >> Now, you could hear people in the background laughing, but the question here is deadly serious. Could this sort of highly rewarded prizefighting and punching increase the aggression of TV viewers? Not only is the answer yes—there's evidence that it may even lead to murder. David Philips, a sociology professor at the University of California, San Diego, published an award-winning study in which he examined all heavyweight championship prize fights between 1973 and 1978, and found that U.S. homicide rates jumped over 12% above average three days after the boxing matches took place, and over 6% above average four days later— increases that translated into nearly 200 additional murders over this five-year period and led Professor Phillips to conclude that "heavyweight prize fights stimulate fatal, aggressive behavior in some Americans." In this research, Professor Phillips also found that the more a fight was publicized, the larger the increase in murder afterwards. And he found that when a Black boxer lost the fight, the murder rate increased for young Black men but not young White men. On the other hand, when a White boxer lost the fight, the murder rate increased for young White men, but not young Black men— a pattern suggesting that aggression was being imitated. So, when it comes to violence on TV or in movies, there's a causal connection to aggression. But what about other forms of media? For example, print media, radio, video games, and so forth. Can they also generate aggression? Absolutely. To take one example, exposure to pornography— whether in the form of magazines or books, DVDs or videos—is causally related to sexual aggression. Here's what a major review concluded after looking at what it called "nonviolent forms of pornography" (things like magazine centerfolds) and violent forms of pornography (things like characters being forced to have sex). "Experimental research shows that exposure to nonviolent or violent pornography results in increases in both attitudes supporting sexual aggression and in actual aggression." As for music and video games, I'll give just a few quick examples of how they can lead to aggression and to a loss in sensitivity toward violence. A 2006 study found that when male college students listened to a couple of songs with sexually aggressive lyrics, the students later showed a level of aggression toward a female confederate that was roughly 50% higher than they showed toward a male confederate, or toward a female confederate when the songs hadn't been aggressive. When you think about how much music college students listen to each day, it's amazing that there was a measurable effect after only two songs. Along similar lines, a 2007 study found that after only 20 minutes of playing a violent video game, participants showed physiological evidence of desensitization when shown a videotape of real-life violence. Specifically, people's heart rate didn't increase, and their galvanic skin response, which is a measure of sweating, didn't show any sign of physical arousal. It was as though they had become deadened, after only 20 minutes of video games. Finally, a 2011 study found a neural desensitization after college students played violent video games. In this study, students were randomly assigned to spend 25 minutes playing either a violent video game like Grand Theft Auto or a nonviolent video game, and then they were shown violent images. What the researchers found was that students who played 25 minutes of violent video games showed less brain activity in response to violence. Their brains have become deadened, or desensitized, to violence. And the researchers found that the more desensitization there was, the more aggression these students later showed in another task, which makes sense. If your brain doesn't respond to violence, then hurting other people isn't a big deal. For those of you who haven't seen a violent video game, let me show you just 20 seconds of a game that's rated as "TEEN"— that is, generally suitable for ages 13 and up. In the full game, people are shot and killed, but in the segment that I'll share with you, there's just a few seconds of the characters shooting. There's no victims and there's no blood. At one point, a version of this game was the number one online action game in the United States. Over nine million copies have been downloaded. What makes the game unique is that it was developed by the U.S. Army as a recruitment tool to get young people to join the Army. Here's the Army's website, and as you can see, there's a page with games and an invitation to "get in on the action" and "have fun." If we scroll down to the video game, the description says, "America's Army, the official game of the U.S Army, delivers an authentic and entertaining army experience." So, here we have a government-funded video game that research suggests will lead teenagers to become more aggressive and more desensitized to violence, and that presents simulated killing as fun entertainment. Now, why do I bring this up? It's not that the game is more extreme than other games on the market—far from it— but rather, that its use as a recruitment tool shows how mainstream and accepted media violence has become, and this acceptance raises certain questions. For example, if you enjoy playing violent video games, and you feel that they haven't made you more aggressive or desensitized you to violence, how do you know you haven't been affected? Life doesn't offer a control group version of you without video games, so what's the best evidence? Another question: Suppose you aren't affected when you play violent video games, but research suggests that other people are. How would you answer a critic who says that you're still contributing to a general culture of violence by making it normative, or normal, to shoot at other people for fun? Regardless of whether you play video games, what do you think about the U.S. military developing a game that might promote aggression or desensitize teenagers to violence? Are they just speaking the language of young people today, just as many other countries have done over the years, or does this cross a line? And finally, what are the most effective steps you can take to reduce the effects of media violence in your life, in your family, and in society? I hope that you'll visit the discussion forum to share what you think, see what others think, and raise further questions for the class to consider. Well, that's a general overview on the effects of media violence, but of course, there are other triggers of aggression as well. Here, for example, are a few important factors that we haven't discussed yet. Most of these are covered in the assigned reading for this week. First, biological factors such as genetics and testosterone. Alcohol use, which, in the United States, is associated with 40% of all violent crimes and two-thirds of all intimate partner violence. In fact, a 2010 study even found that exposure to alcohol-related images and words is enough to increase aggressive thoughts and behavior, presumably because alcohol is paired with aggression in movies, TV shows, and daily life. So, it primes or activates those associations, even when people haven't had any alcohol to drink. Aggression also increases when people are exposed to violent words and images. For example, experimental participants give a higher number of electric shocks to someone when there are guns visible in the room than when no guns are in view. In other words, the very sight of a weapon can prime people to behave aggressively. This kind of priming occurs whether the weapon is a handgun, rifle, or knife, whether the weapon is physically present or just a photo, and whether the study takes place in a laboratory or field setting. What this means, for example, is that you could be watching or reading news coverage about a war, terrorism, or anything else that shows a weapon, and that weapon could prime you to behave aggressively toward others without you ever knowing it. Another trigger of aggression is culture— for example, living in a country or a community that emphasizes honor and machismo. And one last trigger I should mention is physical pain or discomfort. Things like crowding, air pollution, and heat can all increase aggression. For instance, studies have found that during hotter days, months, seasons, and years, aggression increases in the form of domestic violence, criminal assaults, and even major-league batters being hit by pitched baseballs, which is widely seen as an act of aggression by the pitcher. In that regard, it's interesting to speculate whether heat might be playing a role in certain Middle Eastern or African regions that are known to be hotspots or hotbeds of violence— not as a main factor, obviously, but as a secondary factor, a kind of contributing factor that makes aggression more likely. Research by Craig Anderson and his colleagues even suggests that small increases in heat due to climate change may translate into tens of thousands of serious and deadly assaults. This finding was recently supported by a 2013 meta-analysis published by other researchers in the journal Science. The meta-analysis examined 60 different studies and concluded not only that "amplified rates of human conflict could represent a large and critical impact of anthropogenic climate change," but that the effects on group conflict would probably be even larger than the effects on interpersonal conflict. This week's assigned reading discusses aggression in more detail, including ways to reduce aggression, and the message is very consistent with previous topics. If social psychology tells us anything about aggression and media violence, it's to beware of underestimating the power of situational factors— of what we see, what we hear, and what we're entertained by. One of the main reasons that I focus this lecture so much on media violence is that, out of all the different triggers of aggression, this is one of the few in which most of us have a large degree of control, because we have the power of non-participation. In the end, we're the ones who create the playlist. We don't need to listen to lyrics that promote violence against women, or watch TV programs and movies that prime aggression. So, even though aggression isn't the happiest of topics, the ultimate message of this research is incredibly empowering because it shows that individual choices can really make a difference. I'll see you next time.