Chronic violent video game exposure and desensitization to violence: Behavioral and event-related brain potential data

Numerous studies have shown that exposure to media violence increases aggression, though the mechanisms of this effect have remained elusive. One theory posits that repeated exposure to media violence desensitizes viewers to real world violence, increasing aggression by blunting aversive reactions to violence and removing normal inhibitions against aggression. Theoretically, violence desensitization should be reflected in the amplitude of the P300 component of the event-related brain potential (ERP), which has been associated with activation of the aversive motivational system. In the current study, violent images elicited reduced P300 amplitudes among violent, as compared to nonviolent video game players. Additionally, this reduced brain response predicted increased aggressive behavior in a later task. Moreover, these effects held after controlling for individual differences in trait aggressiveness. These data are the first to link media violence exposure and aggressive behavior to brain processes hypothetically associated with desensitization.     

The effect of video game violence on physiological desensitization to real-life violence

Past research shows that violent video game exposure increases aggressive thoughts, angry feelings, physiological arousal, aggressive behaviors, and decreases helpful behaviors. However, no research has experimentally examined violent video game effects on physiological desensitization, defined as showing less physiological arousal to violence in the real world after exposure to video game violence in the virtual world. This experiment attempts to fill this gap. Participants reported their media habits and then played one of eight violent or nonviolent video games for 20 min. Next, participants watched a 10-min videotape containing scenes of real-life violence while heart rate (HR) and galvanic skin response (GSR) were monitored. Participants who previously played a violent video game had lower HR and GSR while viewing filmed real violence, demonstrating a physiological desensitization to violence. Results are interpreted using an expanded version of the General Aggression Model. Links between desensitization, antisocial, and prosocial behavior are discussed.     

Correlates and consequences of exposure to video game violence: hostile personality, empathy, and aggressive behavior

Research has shown that exposure to violent video games causes increases in aggression, but the mechanisms of this effect have remained elusive. Also, potential differences in short-term and long-term exposure are not well understood. An initial correlational study shows that video game violence exposure (VVE) is positively correlated with self-reports of aggressive behavior and that this relation is robust to controlling for multiple aspects of personality. A lab experiment showed that individuals low in VVE behave more aggressively after playing a violent video game than after a nonviolent game but that those high in VVE display relatively high levels of aggression regardless of game content. Mediational analyses show that trait hostility, empathy, and hostile perceptions partially account for the VVE effect on aggression. These findings suggest that repeated exposure to video game violence increases aggressive behavior in part via changes in cognitive and personality factors associated with desensitization.     

The changing face of aggression: the effect of personalized avatars in a violent video game on levels of aggressive behavior

Video game developments allow players to design their own personalized avatars. Previous research has shown that this capability increases levels of aggression within socially acceptable forms of violence. Using the general aggression model (GAM), the current study examined the effect of avatar personalization on behavioral aggression within a violent video game. Participants who played a violent video game and designed their own avatars were significantly more aggressive than those who played the same violent video game with a generic avatar, and were also more aggressive than those who played the nonviolent video game, regardless of whether or not they designed their own personalized characters. Limitations and directions for future research are discussed.     

暴力电子游戏的短期脱敏效应：两种接触方式比较

比较主、被动接触暴力电子游戏的脱敏效应,以44名男性大学生为被试,利用生物反馈仪测量被试主动参与游戏或被动观看游戏录像前后,及随后观看暴力视频过程中皮电与心率的变化（脱敏效应的生理指标）。结果表明：（1）暴力电子游戏可以产生脱敏效应。接触游戏15分钟后,暴力游戏组观看暴力视频过程中皮电的增加值明显小于非暴力游戏组;（2）游戏的接触方式对于脱敏效应的程度无显著影响,但主动参与组对于游戏内容知觉到更高的愉快与更低的沮丧     

I wish I were a warrior: the role of wishful identification in the effects of violent video games on aggression in adolescent boys

This study tested the hypothesis that violent video games are especially likely to increase aggression when players identify with violent game characters. Dutch adolescent boys with low education ability (N=112) were randomly assigned to play a realistic or fantasy violent or nonviolent video game. Next, they competed with an ostensible partner on a reaction time task in which the winner could blast the loser with loud noise through headphones (the aggression measure). Participants were told that high noise levels could cause permanent hearing damage. Habitual video game exposure, trait aggressiveness, and sensation seeking were controlled for. As expected, the most aggressive participants were those who played a violent game and wished they were like a violent character in the game. These participants used noise levels loud enough to cause permanent hearing damage to their partners, even though their partners had not provoked them. These results show that identifying with violent video game characters makes players more aggressive. Players were especially likely to identify with violent characters in realistic games and with games they felt immersed in.     

Effects of realism on extended violent and nonviolent video game play on aggressive thoughts,feelings, and physiological arousal

Previous research has shown that playing violent video game exposure can increase aggressive thoughts, aggressive feelings, and physiological arousal. This study compared the effects that playing a realistic violent, unrealistic violent, or nonviolent video game for 45 min has on such variables. For the purpose of this study, realism was defined as the probability of seeing an event in real life. Participants (N=74; 39 male, 35 female) played either a realistic violent, unrealistic violent, or nonviolent video game for 45 min. Aggressive thoughts and aggressive feelings were measured four times (every 15 min), whereas arousal was measured continuously. The results showed that, though playing any violent game stimulated aggressive thoughts, playing a more realistic violent game stimulated significantly more aggressive feelings and arousal over the course of play. Aggr. Behav. 35:213–224, 2009. © 2009 Wiley‐Liss, Inc.     

Experimental study of the differential effects of playing versus watching violent video games on children's aggressive behavior

There is great concern about the effects of playing violent video games on aggressive behavior. The present experimental study was aimed at investigating the differential effects of actively playing vs. passively watching the same violent video game on subsequent aggressive behavior. Fifty-seven children aged 10-13 either played a violent video game (active violent condition), watched the same violent video game (passive violent condition), or played a non-violent video game (active non-violent condition). Aggression was measured through peer nominations of real-life aggressive incidents during a free play session at school. After the active participation of actually playing the violent video game, boys behaved more aggressively than did the boys in the passive game condition. For girls, game condition was not related to aggression. These findings indicate that, specifically for boys, playing a violent video game should lead to more aggression than watching television violence.     

Neuromodulation can reduce aggressive behavior elicited by violent video games

Research has shown that exposure to violent media increases aggression. However, the neural underpinnings of violent-media-related aggression are poorly understood. Additionally, few experiments have tested hypotheses concerning how to reduce violent-media-related aggression. In this experiment, we focused on a brain area involved in the regulation of aggressive impulses—the right ventrolateral prefrontal cortex (rVLPFC). We tested the hypothesis that brain polarization through anodal transcranial direct current stimulation (tDCS) over rVLPFC reduces aggression related to violent video games. Participants (N = 79) were randomly assigned to play a violent or a nonviolent video game while receiving anodal or sham stimulation. Afterward, participants aggressed against an ostensible partner using the Taylor aggression paradigm (Taylor Journal of Personality, 35, 297–310, 1967), which measures both unprovoked and provoked aggression. Among those who received sham stimulation, unprovoked aggression was significantly higher for violent-game players than for nonviolent-game players. Among those who received anodal stimulation, unprovoked aggression did not differ for violent- and nonviolent-game players. Thus, anodal stimulation reduced unprovoked aggression in violent-game players. No significant effects were found for provoked aggression, suggesting tit-for-tat responding. This experiment sheds light on one possible neural underpinning of violent-media-related aggression—the rVLPFC, a brain area involved in regulating negative feelings and aggressive impulses.     

The effects of reward and punishment in violent video games on aggressive affect, cognition, and behavior

Three experiments examined the effects of rewarding and punishing violent actions in video games on later aggression-related variables. Participants played one of three versions of the same race-car video game: (a) a version in which all violence was rewarded, (b) a version in which all violence was punished, and (c) a nonviolent version. Participants were then measured for aggressive affect (Experiment 1), aggressive cognition (Experiment 2), and aggressive behavior (Experiment 3). Rewarding violent game actions increased hostile emotion, aggressive thinking, and aggressive behavior. Punishing violent actions increased hostile emotion, but did not increase aggressive thinking or aggressive behavior. Results suggest that games that reward violent actions can increase aggressive behavior by increasing aggressive thinking.     

Exposure to violent video games and aggression in German adolescents: a longitudinal analysis

The relationship between exposure to violent electronic games and aggressive cognitions and behavior was examined in a longitudinal study. A total of 295 German adolescents completed the measures of violent video game usage, endorsement of aggressive norms, hostile attribution bias, and physical as well as indirect/relational aggression cross‐sectionally, and a subsample of N=143 was measured again 30 months later. Cross‐sectional results at T1 showed a direct relationship between violent game usage and aggressive norms, and an indirect link to hostile attribution bias through aggressive norms. In combination, exposure to game violence, normative beliefs, and hostile attribution bias predicted physical and indirect/relational aggression. Longitudinal analyses using path analysis showed that violence exposure at T1 predicted physical (but not indirect/relational) aggression 30 months later, whereas aggression at T1 was unrelated to later video game use. Exposure to violent games at T1 influenced physical (but not indirect/relational) aggression at T2 via an increase of aggressive norms and hostile attribution bias. The findings are discussed in relation to social‐cognitive explanations of long‐term effects of media violence on aggression. Aggr. Behav. 35:75–89, 2009. © 2008 Wiley‐Liss, Inc.     

Violent and nonviolent video games produce opposing effects on aggressive and prosocial outcomes

Experimental studies routinely show that participants who play a violent game are more aggressive immediately following game play than participants who play a nonviolent game. The underlying assumption is that nonviolent games have no effect on aggression, whereas violent games increase it. The current studies demonstrate that, although violent game exposure increases aggression, nonviolent video game exposure decreases aggressive thoughts and feelings (Exp 1) and aggressive behavior (Exp 2). When participants assessed after a delay were compared to those measured immediately following game play, violent game players showed decreased aggressive thoughts, feelings and behavior, whereas nonviolent game players showed increases in these outcomes. Experiment 3 extended these findings by showing that exposure to nonviolent puzzle-solving games with no expressly prosocial content increases prosocial thoughts, relative to both violent game exposure and, on some measures, a no-game control condition. Implications of these findings for models of media effects are discussed.     

Grand Theft Auto IV comes to Singapore: effects of repeated exposure to violent video games on aggression

Given the increasingly dominant role of video games in the mainstream entertainment industry, it is no surprise that the scholarly debate about their impact has been lively and well attended. Although >100 studies have been conducted to examine the impact of violent video games on aggression, no clear consensus has been reached, particularly in terms of their long-term impact on violent behavior and aggressive cognitions. This study employs a first-ever longitudinal laboratory-based experiment to examine longer-term effects of playing a violent video game. One hundred thirty-five participants were assigned either to the treatment condition where they played a violent video game in a controlled laboratory setting for a total of 12 hours or to the control group where they did not play a game. Participants in the treatment group played Grand Theft Auto IV over a period of 3 weeks and were compared with a control group on the posttest measures of trait aggression, attitudes toward violence, and empathy. The findings do not support the assertion that playing a violent video game for a period of 3 weeks increases aggression or reduces empathy, but they suggest a small increase in proviolence attitudes. The implications of the findings are discussed.     

The lone gamer: Social exclusion predicts violent video game preferences and fuels aggressive inclinations in adolescent players

Violent video game playing has been linked to a wide range of negative outcomes, especially in adolescents. In the present research, we focused on a potential determinant of adolescents’ willingness to play violent video games: social exclusion. We also tested whether exclusion can predict increased aggressiveness following violent video game playing. In two experiments, we predicted that exclusion could increase adolescents’ preferences for violent video games and interact with violent game playing fostering adolescents’ aggressive inclinations. In Study 1, 121 adolescents (aged 10–18 years) were randomly assigned to a manipulation of social exclusion. Then, they evaluated the violent content of nine different video games (violent, nonviolent, or prosocial) and reported their willingness to play each presented video game. The results showed that excluded participants expressed a greater willingness to play violent games than nonviolent or prosocial games. No such effect was found for included participants. In Study 2, both inclusionary status and video game contents were manipulated. After a manipulation of inclusionary status, 113 adolescents (aged 11–16 years) were randomly assigned to play either a violent or a nonviolent video game. Then, they were given an opportunity to express their aggressive inclinations toward the excluders. Results showed that excluded participants who played a violent game displayed the highest level of aggressive inclinations than participants who were assigned to the other experimental conditions. Overall, these findings suggest that exclusion increases preferences for violent games and that the combination of exclusion and violent game playing fuels aggressive inclinations.

     

Violent and nonviolent video games differentially affect physical aggression for individuals high vs. low in dispositional anger

Although numerous experiments have shown that exposure to violent video games (VVG) causes increases in aggression, relatively few studies have investigated the extent to which this effect differs as a function of theoretically relevant individual difference factors. This study investigated whether video game content differentially influences aggression as a function of individual differences in trait anger. Participants were randomly assigned to play a violent or nonviolent video game before completing a task in which they could behave aggressively. Results showed that participants high in trait anger were the most aggressive, but only if they first played a VVG. This relationship held while statistically controlling for dimensions other than violent content on which game conditions differed (e.g. frustration, arousal). Implications of these findings for models explaining the effects of video games on behavior are discussed.     

The more you play,the more aggressive you become: A long-term experimental study of cumulative violent video game effects on hostile expectations and aggressive behavior

It is well established that violent video games increase aggression. There is a stronger evidence of short-term violent video game effects than of long-term effects. The present experiment tests the cumulative long-term effects of violent video games on hostile expectations and aggressive behavior over three consecutive days. Participants (N = 70) played violent or nonviolent video games 20 min a day for three consecutive days. After gameplay, participants could blast a confederate with loud unpleasant noise through headphones (the aggression measure). As a potential causal mechanism, we measured hostile expectations. Participants read ambiguous story stems about potential interpersonal conflicts, and listed what they thought the main characters would do or say, think, and feel as the story continued. As expected, aggressive behavior and hostile expectations increased over days for violent game players, but not for nonviolent video game players, and the increase in aggressive behavior was partially due to hostile expectations.     

Everyday sadism predicts violent video game preferences

Playing violent video games has become an integral part of the lives of many people, although some people more than others may be predisposed to enjoy violent video games. Two cross-sectional studies examined the extent to which everyday sadism predicts the amount of violent video game play. Past research has shown that everyday sadists obtain pleasure from cruel behaviors. Hence, I reasoned that everyday sadists are drawn to violent video games because killing game characters might be an opportunity to satisfy their need for cruelty. In fact, results revealed a positive link between everyday sadism and the amount of violent video game exposure. Moreover, this relation statistically held when controlling for the impact of trait aggression, the Big 5, narcissism, Machiavellianism, and psychopathy.     

Viewing the world through “blood-red tinted glasses”: The hostile expectation bias mediates the link between violent video game exposure and aggression

Research has clearly shown that violent video games can increase aggression. It is less clear why they do. This study investigates the mediating effect of the hostile expectation bias (i.e., tendency to perceive hostile intent on the part of others) on the link between violent video game exposure and aggression. French college students (N = 136) played either a violent or nonviolent game for 20 minutes. Afterwards, they read ambiguous story stems about potential interpersonal conflicts, and listed what they thought the main characters would do or say, think, and feel as the story continued. Aggression was measured using a competitive computer game in which the winner could blast the loser with loud noise through headphones. As hypothesized, video game violence increased the hostile expectation bias, which, in turn, increased aggression. Effects were larger for men than women. Thus one reason why violent games increase aggression is because they increase hostile expectations.     

Violent Video Games Stress People Out and Make Them More Aggressive

It is well known that violent video games increase aggression, and that stress increases aggression. Many violent video games can be stressful because enemies are trying to kill players. The present study investigates whether violent games increase aggression by inducing stress in players. Stress was measured using cardiac coherence, defined as the synchronization of the rhythm of breathing to the rhythm of the heart. We predicted that cardiac coherence would mediate the link between exposure to violent video games and subsequent aggression. Specifically, we predicted that playing a violent video game would decrease cardiac coherence, and that cardiac coherence, in turn, would correlate negatively with aggression. Participants (N = 77) played a violent or nonviolent video game for 20 min. Cardiac coherence was measured before and during game play. After game play, participants had the opportunity to blast a confederate with loud noise through headphones during a reaction time task. The intensity and duration of noise blasts given to the confederate was used to measure aggression. As expected, violent video game players had lower cardiac coherence levels and higher aggression levels than did nonviolent game players. Cardiac coherence, in turn, was negatively related to aggression. This research offers another possible reason why violent games can increase aggression—by inducing stress. Cardiac coherence can be a useful tool to measure stress induced by violent video games. Cardiac coherence has several desirable methodological features as well: it is noninvasive, stable against environmental disturbances, relatively inexpensive, not subject to demand characteristics, and easy to use. Aggr. Behav. 39:64‐70, 2013. © 2012 Wiley Periodicals, Inc.     

The effects of violent video games on aggression.

Violent content video games such as Mortal Kombat and Doom have become very popular among children and adolescents, causing great concern for parents, teachers, and policy makers. This study cumulates findings across existing empirical research on the effects of violent video games to estimate overall effect size and discern important trends and moderating variables. Results suggest there is a smaller effect of violent video games on aggression than has been found with television violence on aggression. This effect is positively associated with type of game violence and negatively related to time spent playing the games. Directions for future programmatic research on video games are outlined.