Interactive Effect of Moral Disengagement and Violent Video Games on Self-Control,Cheating,and Aggression

Abstract

Violent video games glorify and reward immoral behaviors (e.g., murder, assault, rape, robbery, arson, motor vehicle theft). Based on the moral disengagement theory, we predicted that violent games would increase multiple immoral behaviors (i.e., lack of self-control, cheating, aggression), especially for people high in moral disengagement. High school students (N = 172) who had completed a measure of moral disengagement were randomly assigned to play one of the Grand Theft Auto (GTA) violent video games, or a nonviolent game. Self-control was measured using the weight of uneaten chocolates (i.e., M&M’s) in a bowl by the computer. After gameplay, participants could cheat on a test to win raffle tickets for attractive prizes (e.g., iPad). Aggression was measured using a competitive task in which participants could give an ostensible partner unpleasant noise blasts through headphones. Results showed that violent video games decreased self-control and increased cheating and aggression, especially for people high in moral disengagement.

Keywords

violent video games aggression self-control cheating moral disengagement

On Sunday afternoon, on April 10, 2013, two 15-year-old girls from Udine, Italy, went to a supermarket to buy alcohol. They hitchhiked on the road and were picked up by a 67-year-old man, who drove them to the outskirts of the city. After reaching an open field, the two girls killed the man, took his wallet, and left him in the field. An autopsy later found that the man had been in a “prolonged and violent” fight before he died; two of his ribs were broken. The two girls stole his car and fled, driving high speeds on the highway for 64 km (40 miles), even though neither girl had a driver’s license. When the police caught and questioned the two girls, one said, “I felt like I was playing GTA (Grand Theft Auto), I felt like the hero of the game” (Corriere della Sera, 2013).

GTA is one of the top selling video games in history, having sold over 125 million copies (Video Game Sales Wiki, 2013). The games take place in open worlds where players can choose different missions and can earn points by engaging in immoral activities such as destroying parked vehicles, stealing cars, dealing drugs, and killing pedestrians. Characters can regain health by paying to have sex with a prostitute, and can kill the prostitute afterward to get their money.

Violent video games such as GTA glorify and reward immoral behaviors (e.g., murder, assault, rape, motor vehicle theft). Violent behaviors enacted in the virtual world can also “bleed over” to the real world. A comprehensive meta-analysis of 136 research reports yielding 381 effects from studies involving over 130,000 participants showed that violent games increase aggressive thoughts, angry feelings, physiological arousal, and aggressive behaviors; they also decrease empathic feelings and prosocial behaviors (Anderson et al., 2010; for an alternative perspective see Ferguson & Kilburn, 2010, and response by Bushman, Rothstein, & Anderson, 2010). However, it has been suggested that some people may be more affected by violent video games than others (see Chory, Goodboy, Hixson & Baker, 2007; Eastin, 2006). Accordingly, studies have shown that trait hostility moderate the effects of playing violent video games (Lynch, 1994, 1999) and that the physiological effects of playing violent video games may be greater for children who already show aggressive tendencies. In line with these findings, research has shown that the association between violent video gameplay and delinquency is stronger for those who are characteristically aggressive (Anderson & Dill, 2000). However, more research needs to be conducted in order to understand the key variables that moderate the effects of exposure to violent video games on behavior (see also Gentile, Lynch, Linder, & Walsh, 2004). We argue that the investigation of individual differences is needed to understand the specific effects that violent video games might have on different people.

Moral Disengagement Theory

Many modern video games give players the opportunity to engage in a wide range of immoral activities (e.g., drug dealing, arms trade, assault, and murder). Bandura (1999) first introduced the idea that when people evaluate their actions, self-sanctions can either be enabled or disengaged. Several factors, including stable traits such as the individual tendency toward moral disengagement, are likely to impact the evaluation of reprehensible conduct and make self-sanctions engaged rather than disengaged (Bandura, 1999).

More specifically, according to the moral disengagement theory, people usually adopt moral standards that are meant to inhibit them from engaging in immoral conduct. However, some people convince themselves that moral standards do not apply to them in a particular context, creating a version of reality in which reprehensible conduct becomes morally acceptable. This process, called moral disengagement (Bandura, 1999), may take several forms, such as representing unethical behavior as moral, attributing immoral behavior to external causes, distorting the consequences of behavior, or by dehumanizing victims of unethical behavior. Moral disengagement affects immoral behavior both directly and through its influence on anticipatory guilt reactions, prosocial orientation, and cognitive and affective reactions that are conducive to immoral behavior (Shu, Gino, & Bazerman, 2011). The Moral Disengagement Scale assesses stable individual differences in moral disengagement tendencies (Bandura, Barbaranelli, Caprara, & Pastorelli, 1996). Prior work has shown that moral disengagement predicts engagement in a wide range of immoral behaviors (see Bandura, Caprara, Barbaranelli, Pastorelli, & Regalia, 2001; Bandura et al., 1996; Vollum, Buffington-Vollum, & Longmire, 2004). Drawing on moral disengagement theory (Bandura, 1999), we propose that individuals high in moral disengagement might view reprehensible behaviors in a video game as acceptable or justifiable and that this might leak over to the real world. Specifically, we predict that people who are high in moral disengagement will exercise less self-control, cheat more, and behave more aggressively than others after the game has been turned off.

Does Exposure to Violent Video Games Increase Immoral Behaviors Besides Aggression?

The present research examines the effects of violent video games on three immoral behaviors: lack of self-control, cheating, and aggression. Many studies have examined the impact of violent games on aggression, but to our knowledge none has examined the impact of violent games on lack of self-control or cheating, although some scholars have hypothesized a link (Hartmann & Vorderer, 2010). Self-control is the ability to regulate one’s thoughts, emotions, impulses and desires, and behaviors. Self-control has long been considered one of the most important human virtues. For example, in the Bible it says, “A person without self-control is like a city with broken-down walls” (Proverbs 25:28). Most of the problems that afflict people in our society today have some component of inadequate self-control: drug and alcohol abuse, addiction, anxiety and anger control problems, gambling, violence and crime, and many more. We propose that violent video games encourage people to give in to their selfish inclinations rather than to exercise self-control. In the present study, self-control was operationalized as resisting the temptation to consume delicious chocolates (e.g., DeWall, Deckman, Gailliot, & Bushman, 2011).

Furthermore, this work examines the effects of violent video games on cheating and aggression. Cheating involves acting dishonestly or unfairly in order to gain an advantage. It is widely recognized as an antisocial, undesirable, immoral behavior. Sophocles said, “I would prefer even to fail with honor than to win by cheating.” People even cheat on video games that are meant to be fun, as indicated by the popularity of cheat codes and websites (Fields & Kafai, 2010). In the present study, cheating was operationalized as the number of unearned raffle tickets participants took (e.g., Shu et al., 2011). The tickets could be used to win valuable prizes (e.g., iPad, iPod).

Overview

Based on the moral disengagement theory (Bandura, 1999), we predicted that exposure to violent video games would increase several immoral behaviors (i.e., lack of self-control, cheating, aggression), especially for people high in moral disengagement.

Method

Participants

Participants were 172 Italian high school students (58% male, 13 to 19 years old, M _age = 15.7, SD = 1.47). The parental consent rate was 100%, and the participant assent rate was also 100%.

Procedure

Participants were tested individually at the high school. They were told the study investigated the effects of video games on cognitive abilities. They were randomly assigned to play either a violent (GTA III, GTA San Andreas) or a nonviolent (Pinball 3D, Mini golf 3D) video game for 35 min, after first practicing for 10 min. We used two video games of each type to increase the generalizability of findings (Wells & Windschitl, 1999). All games were pretested to ensure relative equivalence on how enjoyable and boring they were. Games were played on a computer connected to a 19′′ (48.3 cm) display. All games used a third-person perspective for the player. With regard to violent games choice, GTA saga is the best-selling video game in history with over 25 million copies (Bertz, 2012), and along with Pinball 3D, it has been used in previous research (see, e.g., Carnagey, Anderson, & Bushman, 2007; Engelhardt, Bartholow, Bushman, & Kerr, 2011).

Although there are several ways to assess self-control, unhealthy food consumption was chosen for its relevancy for our sample (Strasburger, Jordan, & Donnesrstein, 2010). During the experiment, a bowl containing 100 g of chocolates (i.e., M&M’s) was placed next to the computer. Participants were informed that they could freely eat them, but they were also advised that a high consumption of candy in a short amount of time is unhealthy. These instructions were given in order to make salient to participants that social norms required them to control their impulse of consuming sweet chocolates (for a similar argument, see Baumeister, 2002). Thus, the amount of chocolate left in the bowl was used to measure self-control (e.g., DeWall et al., 2011).

After gameplay, moral standards were measured using the 16-item Moral Disengagement Scale (Bandura et al., 1996; Cronbach’s α = .77), as in our previous research (Gabbiadini, Andrighetto, & Volpato, 2012). Some sample items from the scale are as follows: “Compared to the illegal things people do, taking some things from a store without paying for them is not very serious” and “It is okay to insult a classmate because beating him/her is worse” (1 = completely disagree to 7 = completely agree). As a manipulation check, participants also rated how violent and immoral they thought the game was (1 = not at all to 7 = completely), and reported the title of the video game they played. As a control variable, participants also rated how enjoyable the game was (1 = not at all to 7 = completely).

Next, participants complete measures of cheating and aggression in a counterbalanced order.¹ To measure cheating, participants were told they could earn one raffle ticket for each problem they solved on a 10-item logic test. The raffle tickets could be used to win attractive prizes (3 iPods, 1 iPad, and 6 MP3 players). After 4 min, the students were asked to score their own responses and take a lottery ticket for each item they answered correctly (Shu et al., 2011). Thus, participants could cheat by taking more tickets than they earned from an envelope containing many tickets. Because we knew how many responses participants got correct, and we knew how many tickets were there in the envelope, we could determine the number of unearned tickets they took (i.e., how much they cheated to give themselves an advantage in the raffle).

To measure aggression, participants completed a 10-trial competitive reaction time task with an ostensible partner of the same sex in which the winner could blast the loser with loud noise through headphones. The noise levels ranged from Level 1 = 60 decibels to Level 10 = 105 decibels (about the same level as a fire alarm). A non-aggressive no-noise option (Level 0) was also provided. The winner could also determine the duration of the loser’s suffering by controlling the noise duration (Level 1 = 0.5 sec to Level 10 = 5 sec). The participant won 5 of the 10 trials (randomly determined). The ostensible partner set random noise intensities and durations across the 10 trials. The noise was a mixture of noises that most people hate (e.g., fingernails scratching a chalkboard, dentist drills, sirens). Basically, within the ethical limits of the laboratory, participants controlled a weapon that could be used to blast their partner with unpleasant noise. This is a well-validated measure of laboratory aggression (Giancola & Parrott, 2008; Giancola & Zeichner, 1995), which has been used for decades (Taylor, 1967).

Finally, all participants were fully debriefed. The experimenter explained the use of deception and why it was necessary, disclosed the true purpose of the study, and discussed the potentially harmful effects of violent games. During the prize distribution, about 2 weeks later, a group discussion followed and an additional information sheet about the study was given to all participants. Prizes were distributed to randomly selected students, and textbooks were donated to the school as a token of our appreciation.

Results

Preliminary Analyses

Exemplars of Violent and Nonviolent Video Games

No significant differences were found between the two different violent games or between the two different nonviolent games (all ts < 1.60, ps > .11) on any dependent measure (i.e., self-control, cheating, aggression). Thus, both the two violent games and the two nonviolent games were combined for subsequent analyses.

Video Game Ratings

To assess that the manipulation was successful, we checked the name of the game reported by each participant. All participants correctly indicated the name of the video game they played. Moreover, participants rated violent video games as more violent (M = 5.91, SD = 1.21) than nonviolent video games (M = 1.06, SD = 0.23), t(170) = 36.64, p < .001, d = 5.62. Likewise, violent video games were rated as more immoral (M = 4.99, SD = 1.76) than nonviolent video games (M = 1.57, SD = 1.08), t(170) = 36.64, p < .001, d = 2.35. Thus, the violent game manipulation was successful.

The violent video games (M = 4.89, SD = 1.74) did not differ significantly from nonviolent video games (M = 4.46, SD = 1.50) in rated enjoyment, t(170) = 1.75, p > .08, d = 0.26. Moreover, enjoyment was not a significant predictor of any of the dependent measures (all ts < 1.43, ps > .15). Thus, the reported effects are not due to how enjoyable the games were.

Primary Analyses

A series of moderated regression analyses were used to test the moderating role of moral disengagement on the effects of violent video games on the three immoral behaviors (i.e., lack of self-control, aggression, and cheating).² For each analysis, we entered the interaction variable (Video game condition × Moral disengagement) into a multiple regression at Step 2, after the entry of video game condition and moral disengagement factors independently at Step 1. The interaction between our moderator variable (i.e., moral disengagement) and video game condition was probed using the Johnson & Neyman (1936) technique (see Bauer & Curran, 2005; Hayes & Matthes, 2009), which avoids the need to define arbitrarily values of moral disengagement (e.g., “low,” “high”). Instead, it identifies the regions of the moral disengagement continuum where the effect of video game content on self-control is statistically significant and where it is not. Participant sex was used as a covariate in all analyses.

Self-Control

Regression analysis found violent game players exercised less self-control (i.e., ate more M&M’s: M = 39.22, SD = 30.18) than did nonviolent game players (M = 9.27, SD = 10.60), t(164) = –8.26, p < .001, d = 1.29. There was no main effect of moral disengagement on self-control, t(164) = 1.24, p > .20. Most important, we obtained the predicted interaction between moral disengagement and video game content on self-control, t(164) = 2.26, p < .03, b = 11.30. As can be seen in Figure 1, for moral disengagement scores greater than 1.72 (4.2 percentile), participants who played a violent game exhibited less self-control (i.e., ate significantly more grams of M&M’s) than those who played a nonviolent game. There was a significant negative relationship between moral disengagement and self-control for violent game players, t(164) = 2.42, p < .02, b = 8.13, r = –.26 but not for nonviolent game players, t(164) = –0.83, p > .40, b = –3.17, r = .12. With regard to participant sex, regression analysis also revealed that males ate more M&M’s (M = 30.4, SD = 29.6) than females did (M = 14.2, SD = 19.0), t(164) = –2.92, p < .004, b = –10.35, d = 0.63.

Figure 1.

Relationship between moral disengagement and self-control (i.e., grams of chocolate not eaten) for nonviolent and violent video game players. For moral disengagement scores greater than 1.72, participants who played a nonviolent game ate fewer M&M’s than those who played a violent game.

Cheating

Regression analysis found that violent game players cheated more (M = 1.22, SD = 1.78) than did nonviolent game players (M = 0.14, SD = 0.83), t(164) = 5.03, p < .001, d = 0.79. Moral disengagement was also positively related to cheating, t(164) = 3.03, p < .004, b = 0.49. However, these main effects were qualified by the predicted interaction between moral disengagement and video game content, t(164) = 2.32, p < .03, b = 0.72. As can be seen in Figure 2, for moral disengagement scores greater than 2.29 (13.6 percentile), participants who played a violent game took significantly more unearned raffle tickets than those who played a nonviolent game. There was a significant positive relationship between moral disengagement and cheating for violent game players, t(164) = 3.84, p < .0002, b = 0.79, r = .34, but not for nonviolent game players, t(164) = 0.34, p > .73, b = 0.08, r = .077. In this case, participant sex was not significantly related to cheating, t(164) = –0.82, p > .41.

Figure 2.

Relationship between moral disengagement and cheating (i.e., unearned raffle tickets taken) for violent and nonviolent video game players. For moral disengagement scores greater than 2.28, participants who played a violent game took significantly more unearned tickets than those who played a nonviolent game.

Aggression

A meta-analytic review demonstrated impressive levels of convergence across a wide range of laboratory aggression measures, including intensity and duration of aggression measures, which were correlated .76 (Carlson, Marcus-Newhall, & Miller, 1989). In the present study, noise intensity and duration were also significantly correlated (r = .72, p < .01), and were therefore averaged across the 10 trials and then together to obtain a more reliable measure of aggression (Cronbach’s α = .85). Consistent with many previous studies, violent game players were more aggressive (M = 7.84, SD = 1.55), than were nonviolent game players (M = 6.79, SD = 1.33), t(165) = 4.41, p < .001, d = 0.69. Moral disengagement was also positively related to aggression, t(165) = 1.88, p < .05, b = 0.30. The predicted interaction between moral disengagement and video game content was also significant, t(165) = 1.93, p = .05, b = 0.61. As can be seen in Figure 3, for moral disengagement scores greater than 2.35 (15.1 percentile), participants who played a violent game were significantly more aggressive than those who played a nonviolent game. There was a significant positive relationship between moral disengagement and aggression for violent game players, t(165) = 2.69, p < .008, b = 0.57, r = .35, but not for nonviolent game players, t(165) = –0.16, p > .87, b = –0.03, r = –.02. Males were also more aggressive (M = 7.70, SD = 1.53) than were females (M = 6.7, SD = 1.32), t(164) = 3.21, p < .001, d = 0.69.³

Figure 3.

Relationship between moral disengagement and aggression (i.e., intensity and duration of noise blasts across 10 trials) for violent and nonviolent video game players. For moral disengagement scores greater than 2.35, participants who played a violent game were significantly more aggressive those who played a nonviolent game.

As expected, the three dependent variables (i.e., lack of self-control, cheating, aggression) were all significantly correlated (rs > .29, ps < .0001). In other words, people who exhibited low self-control also cheated more and were more aggressive.⁴

Discussion

The present research replicates previous studies showing that violent video games can increase aggression (Anderson et al., 2010). More important, it expands previous research by showing that that the negative effects of violent games extend to other immoral behaviors. In particular, our study is the first to show that violent video games can also cause people to exhibit less self-control and to cheat. Participants who played a violent video game (GTA) for only 35 min exhibited less self-control, cheated more, and behaved more aggressively than did participants who played a nonviolent video game. Crucially, these effects remained significant even after controlling for participant sex. Many real-world decisions require self-regulation of moral behavior, and our study indicates that playing violent video games can interfere with this ability.

Our previous study was indicative of a link between playing violent games and moral disengagement (Gabbiadini et al., 2012). In the present study, we went further, investigating some possible behavioral outcomes and considering the moral disengagement as an individual difference variable that might moderate violent video game effects. This extension is important because it shows that exposure to violent video games can cause immoral behaviors, especially among people high in moral disengagement. With other research (e.g., Chory et al., 2007; Cicchirillo & Chory-Assad, 2005; Eastin, 2006; Tamborini et al., 2004), the present research moves beyond the question of whether violent games are harmful to address the important question of who is most likely to be harmed by violent games.

In line with previous findings (see Anderson et al., 2010), most of the participants were negatively affected by violent video games. Only those with very low moral disengagement scores were unaffected (recall that the percentiles for self-control, cheating, and aggression were 4.2, 13.6, and 15.1, respectively). Although very few teenagers were unaffected by violent video games, individuals high in moral disengagement were far more affected than those low in moral disengagement. No such relationship emerged following exposure to nonviolent video games, suggesting the specificity of such link for violent video games. Accordingly, considering the moderating role of moral disengagement at the individual level, it seems more appropriate to assess the consequences of violent video games on behavior in terms of a gradient of intensity of the effects rather than just the presence/absence of such consequences. For this reason, we suggest that the moderating role of moral disengagement may shed light on why some individuals who do play with violent video games do not act immorally, whereas others does.

These findings are consistent with moral disengagement theory (Bandura, 1999), and extend the theory to the study of violent video game effects. This is an important extension because violent video games glorify and reward immoral behaviors. The moral choices people make in the real world depend on their personal moral code (Hauser, 2006). It is reasonable to assume that gamers’ reactions to moral situations in video games would be tied to their own personal sense of morality (Shafer, 2012). This research shows that less attachment to moral values can increase the effects of playing violent video games on immoral behaviors.

Limitations and Future Research Directions

There are some limitations to the present research. First, the potential mediating role of self-control on other immoral behaviors (e.g., aggression) needs to be better explored. Thus, although our data did not provide evidence for the mediating role of self-control (see Note 3), future studies should consider the possibility that (low) self-control represents a proximal determinant of a lower adherence to moral behavior, leading to a greater propensity to cheat and behave aggressively. Future research should also consider different behavioral measures of self-control, such as task persistence. Second, future research should test the possibility that violent video games affect levels of moral disengagement. Indeed, as suggested by our data, moral disengagement represents a stable personality trait that may be hardly influenced by situational factors. However, such a link is still plausible, especially if a state measure of moral disengagement is used. Finally, we recognize that the effects we found on immoral behaviors (different from aggression) could be specific to the video game we used in our experiment. GTA has always been considered as a controversial video game for the various criminal behaviors exalted in the game. Further studies should thus compare the effects of GTA to other violent games that do not glorify other immoral behaviors, in order to investigate whether immoral behaviors are just a by-product of being exposed to pure violence.

Conclusion

The present research establishes a causal link between exposure to violent games and real immoral behaviors. In particular, this is the first study to show that playing violent video games can increase cheating and decrease self-control.

We often read about the individuals who act immorally in the daily news, such as the story about the two Italian girls who murdered a man and then stole his cars, just like in GTA. By far, the people most likely to show poor self-control, cheat, and aggression against others in the present experiment were those high in moral disengagement. These results may shed light on why some individuals who play violent video games act immorally, whereas others do not.

Footnotes

Acknowledgment

The authors declare that they have no competing interests or any business relationships with the manufacturers of the video games and products cited in the text. We want to thank “G. Maironi da Ponte” high school institute, especially Professor Mazzotti and Dott. Maffeis for allowing us to collect data in their school.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

Notes

References

Anderson

C. A.

Dill

K. E.

(2000). Video games and aggressive thoughts, feelings, and behavior in the laboratory and in life. Journal of Personality and Social Psychology, 78, 772–790.

Anderson

C. A.

Shibuya

Ihori

Swing

E. L.

Bushman

B. J.

Sakamoto

… Saleem

. (2010). Violent video game effects on aggression, empathy, and prosocial behavior in Eastern and Western countries. Psychological Bulletin, 136, 151–173. doi:10.1037/a0018251

Bandura

. (1999). Moral disengagement in the perpetration of inhumanities. Personality & Social Psychology Review, 3, 193–209. doi: 10.1207/s15327957pspr0303_3

Bandura

Barbaranelli

Caprara

G. V.

Pastorelli

(1996). Mechanisms of moral disengagement in the exercise of moral agency. Journal of Personality and Social Psychology, 71, 364–374. doi:10.1037/0022-3514.71.2.364

Bandura

Caprara

G. V.

Barbaranelli

Pastorelli

Regalia

(2001). Sociocognitive self-regulatory mechanisms governing transgressive behavior. Journal of Personality and Social Psychology, 80, 125–135. doi:10.1037/0022-3514.80.1.125

Bauer

D. J.

Curran

P. J

. (2005). Probing interactions in fixed and multilevel regression: Inferential and graphical techniques. Multivariate Behavioral Research, 40, 373–400. doi:10.1207/s15327906mbr4003_5

Baumeister

R. F.

(2002). Yielding to temptation: Self-control failure, impulsive purchasing, and consumer behavior. Journal of Consumer Research, 28, 670–676.

Bertz

. (2012, April). Game informer, pp. 38–55.

Bushman

B. J.

Rothstein

H. R.

Anderson

C. A.

(2010). Much ado about something: Violent video game effects and a school of red herring: Reply to Ferguson and Kilburn. Psychological Bulletin, 136, 182–187.

10.

Carlson

Marcus-Newhall

Miller

(1989). Evidence for a general construct of aggression. Personality and Social Psychology Bulletin, 15, 377–389.

11.

Carnagey

N. L.

Anderson

C. A.

Bushman

B. J.

(2007). The effect of video game violence on physiological desensitization to real-life violence. Journal of Experimental Social Psychology, 43, 489–496.

12.

Chory

R. M.

Goodboy

A. K.

Hixson

Baker

. (2007, November). Emotion-based traits as moderators of the violent video game play-aggression relationship: The roles of affective orientation and empathy. Paper presented at the annual meeting of the NCA 93rd Annual Convention, TBA, Chicago, IL. Abstract retrieved from http://www.allacademic.com/meta/p188138_index.html

13.

Cicchirillo

Chory-Assad

R. M.

(2005). Effects of affective orientation and video game play on aggressive thoughts and behaviors. Journal of Broadcasting & Electronic Media, 49, 435–449.

14.

Sera

Corriere della

. (2013, April 10). Delitto di Udine, il racconto delle ragazzine «Era come stare nel videogame Gta» [Udine, the story of young girls “It was like being in the video game GTA»]. Corriere della Sera. Retrieved from http://www.corriere.it/cronache

15.

DeWall

C. N.

Deckman

Gailliot

M. T.

Bushman

B. J.

(2011). Sweetened blood cools hot tempers: Physiological self-control and aggression. Aggressive Behavior, 37, 73–80. doi:10.1002/ab.20366

16.

Eastin

M. S.

(2006). Video game violence and the female game player: Self- and opponent gender effects on presence and aggressive thoughts. Human Communication Research, 32, 351–372. doi:10.1111/j.1468-2958.2006.00279.x

17.

Engelhardt

C. R.

Bartholow

B. D.

Kerr

G. T.

Bushman

B. J.

(2011). This is your brain on violent video games: Neural desensitization to violence predicts increased aggression following violent video game exposure. Journal of Experimental Social Psychology, 47, 1033–1036.

18.

Ferguson

C. J.

Kilburn

(2010). Much ado about nothing: The misestimation and overinterpretation of violent video game effects in Eastern and Western nations: Comment on Anderson et al. (2010). Psychological Bulletin, 136, 174–178. doi:10.1037/a0018566

19.

Fields

D. A.

Kafai

Y. B

. (2010). “Stealing from grandma” or generating cultural knowledge? Contestations and effects of cheating in a tween virtual world. Games and Culture 5, 64–87. doi:10.1177/1555412009351262

20.

Gabbiadini

Andrighetto

Volpato

. (2012). Brief report: Does exposure to violent video games increase moral disengagement among adolescents? Journal of Adolescence, 35, 1403–1406. doi:https://dx-doi-org.web.bisu.edu.cn/10.1016/j.adolescence.2012.06.001

21.

Gentile

D. A.

Lynch

P. J.

Linder

J. R.

Walsh

D. A.

(2004). The effects of violent video game habits on adolescent aggressive attitudes and behaviors. Journal of Adolescence, 27, 5–22.

22.

Giancola

Parrott

(2008). Further evidence for the validity of the Taylor aggression paradigm. Aggressive Behavior, 34, 214–229. doi:10.1037/a0025207

23.

Giancola

P. R.

Zeichner

(1995). Construct validity of a competitive reaction- time aggression paradigm. Aggressive Behavior, 21, 199–204. doi:10.1002/1098-2337

24.

Hayes

A.F.

(2013). An introduction to mediation, moderation, and conditional process analysis: A regression-based approach. New York: Guilford Press.

25.

Hayes

A. F.

Matthes

(2009). Computational procedures for probing interactions in OLS and logistic regression: SPSS and SAS implementations. Behavior Research Methods, 41, 924–936. doi:10.3758/BRM.41.3.924

26.

Hartmann

Vorderer

(2010). It's okay to shoot a character: Moral disengagement in violent video games. Journal of Communication, 60, 94–119. doi:10.1111/j.1460-2466.2009.01459.x

27.

Hauser

M. D.

(2006). Moral minds. New York, NY: HarperCollins.

28.

Johnson

P. O.

Neyman

(1936). Tests of certain linear hypotheses and their application to some educational problems. Statistical Research Memoirs, 1, 57–93.

29.

Lynch

P. J.

(1994). Type A behavior, hostility, and cardiovascular function at rest and after playing video games in teenagers. Psychosomatic Medicine, 56, 152.

30.

Lynch

P. J.

(1999). Hostility, Type A behavior, and stress hormones at rest and after playing violent video games in teenagers. Psychosomatic Medicine, 61, 113.

31.

Shafer

D. M

. (2012). Moral choice in video games: An exploratory study. Media Psychology Review, 5. Retrieved from http://mprcenter.org/mpr

32.

Shu

L. L.

Gino

Bazerman

M. H.

(2011). Dishonest deed, clear conscience: When cheating leads to moral disengagement and motivated forgetting. Personality and Social Psychology Bulletin, 37, 330–349.

33.

Strasburger

V.C.

Jordan

A.B.

Donnerstein

. (2010). Health effects of media on children and adolescents. Pediatrics, 125, 756–767.

34.

Tamborini

Eastin

M. S.

Skalski

Lachlan

Fediuk

T. A.

Brady

(2004). Violent virtual video games and hostile thoughts. Journal of Broadcasting and Electronic Media, 48, 335–357.

35.

Taylor

S. P.

(1967). Aggressive behavior and physiological arousal as a function of provocation and the tendency to inhibit aggression. Journal of Personality, 35, 297–310.

36.

Video Game Sales Wiki. (2013). Best selling game franchises. Retrieved from http://vgsales.wikia.com/wiki/Franchise

37.

Vollum

Buffington-Vollum

Longmire

D. R.

(2004). Moral disengagement and attitudes about violence toward nonhuman animals. Society & Animals, 12, 209–235.

38.

Wells

G. L.

Windschitl

P. D.

(1999). Stimulus sampling and social psychological experimentation. Personality and Social Psychology Bulletin, 25, 1115–1125. doi:10.1177/01461672992512005

39.

Yzerbyt

Muller

Judd

C. M.

(2004). Adjusting researchers' approach to adjustment: On the use of covariates when testing interactions. Journal of Experimental Social Psychology, 40, 424–431.