Video games cause violent behavior. For a while now this idea has circulated in the public mainstream, wreaking havoc on the minds of protective parents and, indeed, their video game consuming children.
This concern has perhaps always pervaded people's intuition but recent events have made this concern more palpable. Many violent crimes that have been highlighted in the media have been linked to violent video game use: a school shooting spree in Santee, California (March, 2001); a violent crime spree in Oakland, California (January, 2003); five homicides in Long Prairie and Minneapolis, Minnesota (May,2003); beating deaths in Medina, Ohio (November, 2002) and Wyoming, Michigan (November, 2002); school shootings in Wellsboro, Pennsylvania (June, 2003) and Red Lion, Pennsylvania (April, 2003); and the Washington, DC.''Beltway'' sniper shootings (Fall, 2002) (Anderson, 2004).
This anecdotal evidence has spurned more solid science by psychological researchers. The empirical inquiries, in turn, have validated this disconcerting notion - video games seem to cause - not just correlate with - violent behavior. This is neither speculation nor rock hard fact; it is empirical data that warrants serious attention.
Before turning to the conclusive findings, let's warm up with a review of what we know about aggressive behavior, namely the idea that aggression is much easier to induce than we'd like to think. The general literature on aggression paints the picture of people as naturally aggressive beings who must perpetually and exhaustively fight off their more base instincts. This is supported by evidence that we can be subtly nudged toward more violent thoughts, feelings and behaviors. For instance, we become more violent after watching violent sports on television, as national prevalence rates show that daily homicide rates across the country increase after nationally televised boxing matches (Phillips & Hensley, 1984). Other studies have shown that simple cues for aggression are associated with increased violent cognitions and behaviors. Merely viewing a picture of a gun or other weapon, for example, increases the accessibility of aggressive thoughts (e.g., Anderson et al., 1996) - this is known as the "weapons effect." Further, seemingly unrelated internal and external events, such as being mildly provoked or frustrated (i.e. someone cutting you in line) or unpleasant odors and hot temperatures have all been shown to increase aggression in the moment (Berkowitz, 1989).
The General Aggression Model (Bushman & Anderson, 2002) is one of the more popular theories put forth in the psychological literature that strives to explain these head-scratching outcomes and the underlying processes of aggression.
This model suggests that aggressive people are aggressive because they expect to be attacked, and they are primed and ready to engage in aggression as a response to being attacked. They are quick to experience aggressive related thoughts (i.e. I want to hit you), feelings (i.e. I'm feeling really frustrated and angry right now) and physiological arousal (i.e. racing heart). Further, and this almost goes without saying, aggressive people have a tough time with impulse control, tend to misinterpret ambiguous moments as hostile, and assume that hostile actions by others are intentional and not accidental (the hostile attribution bias). An aggressive person also harbors positive views of violence, believing that violence is the most effective response to a given problem. They also have more easily accessible scripts for violence, meaning, they are quicker to resort to violence as the normal and acceptable protocol. For instance, if someone punches you in the face there is a high likelihood that you will feel anger, but what specific response will this anger facilitate? There is a litany of options, ranging from fleeing the situation to questioning the attacker's intent with a loud tone of voice, but the General Aggression Model suggests that an aggressive person will swing right back because this action is a well-rehearsed response to such situations (having become automated through various learning channels - watching a parent act this way, having previously reinforcing experiences like winning a school yard fight and being praised by peers, etc.).
Circling back to video games, the question then becomes, do violent video games strengthen these aggressive tendencies highlighted in the General Aggression Model, and to what degree?
The short answer is "Yes" and "significantly so." A meta-analysis, or a review of numerous studies on the matter, demonstrated that exposure to violent video games served as a causal risk factor for increased aggressive behavior, aggressive cognition, and aggressive affect, as well as decreased empathy and pro-social behavior (Anderson et al., 2010). Meaning, violent video game exposure was not simply associated with but, in fact, engendered elevated tendencies in aggression. Every single facet of aggression - thoughts, feelings, behaviors - was increased. And altruism and empathy, the processes that might inhibit aggression, were decreased. Further, this meta-analysis also highlighted the point that video game-induced aggression occurred in the short-term (in the lab, immediately after the experimental intervention of playing a video game), and more disturbingly, in the long-term (as measured by outcomes like delinquency).
The findings of some earlier, more specific studies zoom in on how this process unfolds.
For starters, video games increase the physiological arousal needed for aggressive behavior. While playing violent video games our glands start to sweat, our heart begins to race, and our breathing rate becomes more shallow and labored (Anderson & Dill, 2000). This fact alone wouldn't necessarily influence aggressive behavior except for the plethora of social psychological literature that suggests we as human beings are pretty inept at properly interpreting and managing arousal. Our physiology may be in response to video games but we don't necessarily make that connection, or effectively reduce the arousal in subsequent situations (Zillman, Katcher, & Milavsky, 1972). In other words, imagine that I experienced aroused from video games, and then went for a walk. On this walk imagine that I received mildly irritating comments from a neighbor. I would be much more likely to respond with uncharacteristic aggressiveness simply because I started the walk with an increased baseline of arousal that is now playing tricks on my mind and making me feel more attacked than I'm actually being.
In addition to this link between violent video games and aggression-facilitating arousal is the bridge to aggressive cognitions or thoughts. One study randomly assigned young adults to play a violent or a nonviolent video game and then measured the time it took each group to recognize and begin pronouncing aggressive words. The results showed that aggressive thoughts were significantly more accessible to those who had just finished playing a violent video game (Anderson & Dill, 2000).
How about those more nuanced aggression-related thoughts, such as expectations of hostile reactions from others in ambiguous situations - can video games influence our thought process to such a problematic extent?
Yes, studies showed that simply playing a violent video game for 20 minutes produced significant increases in expectations that potential conflict-laden situations would be handled aggressively (Bushman & Anderson, 2002). How was this demonstrated empirically? The study randomly assigned college student participants to play one of four violent or four nonviolent video games. Afterward, they were given ambiguous story stems about potential interpersonal conflicts. They were asked what the main character will do, say, think, and feel as the story continues. Those that played a violent video game described the main character as behaving more aggressively, thinking more aggressive thoughts, and feeling more aggressive versus the participants who had played a nonviolent video game (Bushman & Anderson, 2002).
If you need more supporting evidence for the relationship between violent video games and engagement in real-world violence then we can turn to neuro-imaging studies to seal the deal. In one neuropsychological experiments participants played a violent or nonviolent video game, and viewed violent and nonviolent photos while their brain activity was measured (Engelhardt, Bartholow, Kerr, & Bushman, 2011). They then gave an ostensible opponent unpleasant noise blasts (this is the most violent that ethics boards will let research subjects get). Those participants who played a violent (relative to a nonviolent) video game showed less activation in the part of the brain associated with response to violent images. In other words, they were more desensitized to the violence. Predictably, this lack of sensitization influenced an increase in aggression, in this case, more unpleasant noise blasts. These data provide the first experimental evidence linking violence desensitization with increased aggression, and show that a neural marker of this process can at least partially account for the causal link (Engelhardt, et al., 2011).
To provide some perspective on the degree of violence that is influenced by video games, research suggests that the effects are more powerful than that of watching violent television and film (Anderson, Gentile, & Buckley, 2007). Moreover, the effect size - the strength of the relationship between video game violence and aggression - is approximately .26 (Anderson, 2004). What does this mean? It means that the relationship between gaming and aggression is stronger than the relationship between condom use and decreased HIV risk, and between second-hand smoke and lung cancer, even the effect of calcium intake on bone mass density!