Do violent video games cause violent behavior?

Question

I have been following this question casually over the past couple of years, and it seemed to me that there was no strong consensus either way on the subject. However, I recently read an editorial from one of the scientists involved in the Supreme Court case, Schwarzenegger vs. EMA, arguing that the evidence for psychological and physical damage to children is strong.

On the other hand, a quick check of the wikipedia article on the subject seemed to confirm my original impression, that there was still significant controversy on the subject.

Answer 1

We don’t know.¹

Despite many studies conducted, so far no consensus has emerged whether violent video games cause a long-term, sustained increase in violent behaviour. On the other hand, it seems increasingly likely that if such an effect exists, it is probably small: at most, video games have a minor overall influence on violent behaviour.

Wikipedia has a break-down of the discussion with references to the relevant studies. Given the wide variability of individual studies’ results, the best available evidence is summarised in meta-analyses, of which there are also several.

But even these meta-analyses reach different conclusions, partially because there’s disagreement even about the correct meta-analysis methodology. Some of the scientific publications in this area are unusually vitriolic, and personally attack other scientists (on both sides of the debate).

So here’s a representative (rather than exhaustive) overview of different conclusions, focussing on the more recent meta-analyses.

• A 2010 study by Craig A. Anderson & al. concludes that

  [t]he evidence strongly suggests that exposure to violent video games is a causal risk factor for increased aggressive behavior, aggressive cognition, and aggressive affect and for decreased empathy and prosocial behavior.

  And that

  playing violent video games is a significant risk factor for both short-term and long-term increases in physically aggressive behavior.

  The study was variously criticised based on a number of methodological flaws. In particular, one reanalysis by Joseph Hilgard & al. points out that unaccounted-for publication bias decreases the evidence, potentially rendering it non-significant. The original authors acknowledge some of these shortcomings but stand by their original conclusion.

• A 2015 study by Christpher J. Ferguson reached pretty much the opposite conclusion: that

  video game influences on increased aggression […] are minimal.

  The meta-analysis spends significant time identifying weaknesses in existing studies, and attempts to work around these, in particular publication bias. This study was published alongside multiple reviews which both support and criticise the study. One criticism in particular is the original study’s reliance on controlled effect sizes which, in a nutshell, attempt to account for independent factors that influence the effect size (= the magnitude of the measured effect).

  Proponents of using controlled effect size point out that lack of controlling for these independent variables is known to over-inflate effect size (Patrick M. Markey, 2015). Ferguson includes the following example:

  boys play more violent video games […] and are also more aggressive than girls. Thus, one is likely to see bivariate correlations between video game violence use and aggression that are simple gender effects

  Detractors such as Paul Boxer & al. (2015) and Hannah R. Rothstein & Brad J. Bushman (2015) contend that this kind of adjustment is “unreliable and invalid” because it “overcorrects”, and “because the statistical theory underlying meta-analytic procedures assumes that one is working with raw (zero-order) correlations” (Anderson & al., 2010) — in other words, use of controlled effect sizes violates the assumption that effects such as those in the above example do not exist.² In a reply, Ferguson calls these claims “problematic both statistically and theoretically”.

  Finally, Ferguson’s meta-analysis was subsequently defended on theoretical grounds (in particular regarding the use of controlled effect sizes) as well as reanalysed in 2016 by Luis Furuya-Kanamori & Suhail A. Doi using “improved meta-analytical model” (to invalidate the main criticism discussed above). This study

  confirmed the main results of Ferguson’s meta-analysis. There was a significant yet very small effect on aggressive behavior of exposure to both general […] and violent […] video games.

• A 2020 study by Aaron Drummond & al. focussing on long-term effects found that

  [o]verall, longitudinal studies do not appear to support substantive long-term links between aggressive game content and youth aggression. Correlations between aggressive game content and youth aggression appear better explained by methodological weaknesses and researcher expectancy effects than true effects in the real world.

  And

  effect sizes were lower for better-designed studies and those with less evidence for researcher expectancy effects.

  That is: the higher quality the study, the less evidence for a causal effect of violent video games on violent behaviour.

Given the wide variety of conclusions from research studies, it’s instructive to survey the opinion of researchers in the field. This was done by Brad J. Bushman & al. in 2015. Their conclusion is:

Although a few vocal researchers claim there is a “debate” on this issue, the overwhelming majority of researchers believe that violent media increase aggression in children, and that the relationship is causal.

Notably, they surveyed not only the effect of video games but of other types of “violent media” as well, including “violent literature” and “violent music”, which the majority of researchers also believes can increase aggression.

Conversely, there is no majority who believes that this causal effect is a “major factor in real-life violence”. In other words: even though most believe there is an effect, most either believe that this effect is ultimately not a major factor, or don’t know:

(Numbers from Brad J. Bushman & al. (2015))

---

_{¹ This was written in 2011, and depressingly the answer hasn’t really changed, though the number of studies has. One thing that has changed is that studies have become less likely to argue for large, causal effects.}

_{² Stated like this, the claim seems obviously false, since it is clearly contradicted by the example. However, it’s not that simple: the statistical model underlying meta-analyses uses a simplifying assumption. The simplifying assumption may produce false results because it does not reflect reality, as argued e.g. by Ferguson. However, on the flip side, when using different assumptions one needs to adjust the statistical model. His critics claim Ferguson has not done this: he continues to use a statistical model that assumes different inputs from what he provides by controlling the effect size.}

Answer 2

The Swedish Media Council released a report reviewing the state of the research in Swedish, I've summarized and translated below. There is also an article published in English over on the local. From the summarized version of the report:

The Swedish Media Council has gone through research databases and gathered studies on violent videogames effects on aggression that has been published in international research journals in the period 2000-2011. Literature searches resulted in 161 papers that contained 106 unique empirical studies. The remaining 55 studies contained of metastusdies, research overviews, scientifical debate [not sure what the correct translation of vetenskapliga debattartiklar is], methodological critiques or comments to other papers.

Some key findings:

• 67% of the studies are done in the lab and do report increased aggression, but only 7% measured aggression before and after. The measured effect remains for 4-30 minutes, and it's unknown if there's long term effects.

• 22% are done via questionnaires where it's a 50/50 split if there's an increase or not, with the ones showing no effect being more thorough.

• 11% are longitudinal (usually questionares) with 11 of 12 reporting on increased aggression, but only 3 of them gathered backgrounds data like family conditions and general psychological well being.

The report raises 3 main issues with the research showing that agression is linked to violent video games:

1. The studies measure agression by judging it on a persons agressive feelings, thoughts, associations and attitudes. But the report stat that the link between those things and a manifestation of agression is lacking empirical support.

2. It's not clear from the research if the people would react in the same way when they are outside of a laboratory setting.

3. The research fails to take in relevant background information and the studies show that the inclination to play violent video games and agressive behavior both depend on things like a bad family situation.

It does say that there is a statistical correlation between violent video games and agression, but that it's not a causal one explaining, in reviewing the conclusions:

1. It's more common for the research to show that violent video games cause agression, but there are severe methodological problems with this research, and therefore it has not been proven.

2. That violent video games would cause agression in people that have this tendency already hasn't been explored deep enough to be conclusive in any way. The studies that show this can be interpreted this way as well as 3, 4.

3. The inverted causality that agressive people play violent video games has been shown thoroughly in the research.

4. Other factors like family conditions cause both agression and playing violent video games has been shown in the research that explores this.

In conclusion they comment that 8 other meta studies has been published by (non-Swedish) government agencies and independent research organizations in the 21th-century and that this one is in line with the previous ones. They also state that while the research doesn't show that this effect is not proof that it's not there at all. However if there is an effect then it would be a really small one.

Answer 3

Having just read a Slashdot article "Violent Games Credited With Reducing Crime Levels" on this topic that suggests that violent video games reduce violent crime, I thought it worthwhile to post it to this interesting thread.

The Slashdot article cites the paper "Understanding the Effects of Violent Video Games on Violent Crime", dated April 7, 2011, the abstract for which is (my emphasis):

Psychological studies invariably find a positive relationship between violent video game play and aggression. However, these studies cannot account for either aggressive effects of alternative activities video game playing substitutes for or the possible selection of relatively violent people into playing violent video games. That is, they lack external validity. We investigate the relationship between the prevalence of violent video games and violent crimes. Our results are consistent with two opposing effects. First, they support the behavioral effects as in the psychological studies. Second, they suggest a larger voluntary incapacitation effect in which playing either violent or non-violent games decrease crimes. Overall, violent video games lead to decreases in violent crime.

The answer, based on this study, is: Violent video games cause or correlate with an increase in violent behaviour. However, it's worth noting that this violent behaviour is offset by the distraction and release of aggression through playing of the (violent or non-violent) video games, resulting in an overall reduction in violent crime.

While this study purports to answer the question, a lack of consensus is likely to remain on the topic. I think this study is, however, an important piece.

— EDIT —

I would also add a reference to the article No link found between movie, video game violence and societal violence (2014), which is summarized:

Christopher Ferguson (Stetson University) published his findings in the Journal of Communication. Ferguson conducted two studies that raised the question if whether the incidence of violence in media correlates with actual violence rates in society. The first study looked at movie violence and homicide rates between 1920 and 2005. The second study looked at videogame violence consumption and its relationship to youth violence rates from 1996-2011. He found that societal consumption of media violence is not predictive of increased violence rates in society.

and

"Entertainment Software Ratings Board ratings were used to estimate the violent content of the most popular video games for the years 1996-2011. These estimates of societal video game violence consumption were correlated against federal data on youth violence rates during the same years. Violent video game consumption was strongly correlated with declines in youth violence. However, it was concluded that such a correlation is most likely due to chance and does not indicate video games caused the decline in youth violence. ... Previous studies have focused on laboratory experiments and aggression as a response to movie and videogame violence, but this does not match well with real-life exposure.

It may be worth noting that this appears to be the first article by Christopher Ferguson on the topic.

Answer 4

Video games have been shown to raise aggression when played and directly afterwards and much of the evidence I have seen points to the effect described above whereby violent people are attracted to violent video games.

There is little to link violence to explicit video games but some that suggests in some cases it may increase anti-social behaviour.

Firstly a caveat - research on violence and video games is limited, from Adachi et al (2011) "The effect of violent video games on aggression: Is it more than just the violence?"

Experimental research has shown that playing violent video games produces higher levels of aggressive cognition, aggressive affect, physiological arousal, and aggressive behavior (in the short-term) than nonviolent video games. However, there are two major limitations with these investigations. First, the majority of experimental studies that have compared the effects of violent versus non-violent video games on aggression have failed to equate these games in terms of competitiveness, difficulty, and pace of action. Thus, although the common finding is that violent video games produce higher levels of aggression than non-violent video games, other unmatched factors beyond the actual violent content may be responsible for the elevated levels of aggression. Second, previous experimental studies have tended to use a measure of aggression that may also measure competitiveness, leading to questions about whether violent video games are related to aggression or competitiveness.

On the subject of violent video games having negative outcomes, Gentile and Anderson stated in in "Taking Sides" (p. 1098-5409):

Gentile and Anderson believe the research has made it clear that playing violent videogames leads to violent behavior. These researchers claim that several things happen when a child is playing violent games: an increase in physiological arousal, aggressive cognitions and emotions, aggressive behaviors, and decreased pro-social behaviors.

However the co-author (the book is a debate type thing) states:

That there is not a causal connection between violent video games and violent behavior. In the second article, she summarizes several of her relevant research studies, including multiple qualitative and quantitative projects, a survey of over 1,000 middle school-aged children, and in-depth conversations with 42 youths in focus groups. While she allows that some individuals may have bad experiences with video games, she reports that playing such games, even violent ones, is a normal part of adolescent development. Indeed, they may even have pro-social and relationship-building consequences.

Williams (2011) "The effects of homophily, identification, and violent video games on players":

After an experiment with 148 male participants, results indicated that skinning a video game character to physically resemble the player led to greater identification and psychological involvement with the game's character but did little to impact the feeling of presence. Exposure to violent content also led to greater physical hostility than exposure to nonviolent content. An interaction effect revealed playing a violent game with a character physically resembling the player led to even greater hostility.

Sester and Bartholemew (2011) "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.

Bosche (2010) "Violent video games prime both aggressive and positive cognitions":

Previous studies have shown that violent video games prime aggressive thoughts and concepts. Interestingly, positively valenced test stimuli are rarely used in this field, though they might provide useful information on the nature of the emotional response to virtual violence and its associative structure. According to the General Aggression Model (GAM) and its extensions (Carnagey, Anderson, & Bushman, 2007), normal negative reactions to violence are expected. Alternatively, playing violent video games might be construed as engaging in positively valenced playful fighting behavior. To test the potential of violent video games to prime positive concepts, N = 29 adult males played either a violent or a nonviolent video game for 20 minutes and were subsequently tested in a standard lexical decision task consisting of positive, aggressive, nonaggressive negative, and neutral target words. The data show that the violent video game primed aggressive concepts as expected, but also raised positive concepts, and did so independently of the participants’ history of playing violent video games. Therefore, the results challenge the idea that violent video games inherently stimulate negative concepts only.

Answer 5

Johnson, Jones, Scholes, and Carras ⁽²⁰¹³⁾ published a review of research literature that mostly focused on the positive aspects of video gaming, which they argue have been overlooked due to dominant societal preoccupations with theories about its effects on violent behavior ^{(Kutner & Olson, 2008; Ferguson, 2007; Ferguson et al., 2013)}. They include a section reviewing violent games specifically though, which I'll paraphrase here.

As others have already noted, existing research on relationships between video games and violence has been insufficient and heavily criticized. A relatively convincing study found longitudinal relationships between playing violent video games and being rated as more aggressive by teachers and peers ^{(Gentile & Gentile, 2008)}. However, problems with other studies have included publication bias and unsupported generalizations from in-lab results to behaviors in normal contexts ^{(Boyle, Connolly & Hainey, 2011; Ferguson, 2007; Kutner & Olson, 2008; Sherry, 2004, 2007)} and dependence on self-reported subjective experiences ^{(Lemmens et al., 2011; Möller & Krahé, 2009; Anderson et al., 2010; Shibuya, Sakamoto, Ihori, & Yukawa, 2008)} or self-reported aggressive behaviours ^{(Shibuya et al., 2008; Bucolo, 2010)}. Criticisms aside, two of these studies did not demonstrate any sustained causal relationships anyway ^{(Lemmens et al., 2011; Shibuya et al., 2008)}.

After correcting for publication bias, Ferguson ⁽²⁰⁰⁷⁾ found no meta-analytic support for the relationship. Ferguson and colleagues ⁽²⁰¹³⁾ later found no effects in their own study either, and claimed to have eliminated the likelihood of a false null result. Anderson and colleagues ⁽²⁰¹⁰⁾ did one of those controversial meta-analyses supporting the relationship that's listed in the Wikipedia page to which @KonradRudolph's accepted answer links, but Wikipedia covers that particular controversy well enough already, so I'll leave it alone. Suffice it for here to say that Ferguson and Kilburn ⁽²⁰¹⁰⁾ weren't convinced.

Johnson and colleagues ⁽²⁰¹³⁾ also recommend Carras et al. (in prep), "For a more complete exploration of these issues and the research regarding long-term outcomes of videogame play," but it looks like they haven't completed their analyses yet at this time. BTW, I have cited Johnson and colleagues for a related answer on Cognitive Sciences about the addictive quality of gaming.

References

<sup>- Anderson, C. A., Shibuya, A., Ihori, N., Swing, E. L., Bushman, B. J., Sakamoto, A., Rothstein, H. R., & Saleem, M. (2010). Violent video game effects on aggression, empathy, and prosocial behavior in eastern and western countries: A meta-analytic review. Psychological Bulletin, 136(2), 151–173. Retrieved from http://lilt.ilstu.edu/mjreese/psy453/Anderson%20et%20al,%202010.pdf.
- Boyle, E., Connolly, T. M., & Hainey, T. (2011). The role of psychology in understanding the impact of computer games. Entertainment Computing, 2(2), 69–74.
- Bucolo, D. (2010). Violent video game exposure and physical aggression in adolescence: Tests of the General Aggression Model. University of New Hampshire.
- Carras, M. C., Johnson, D., & Jones, C. (2014). Adverse effects of videogame play on health, behavioral and educational outcomes in longitudinal studies of young people (unpublished manuscript). Further info available at http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002882#.Uww4b4V5Pmw.
- Ferguson, C. J. (2007). The good, the bad and the ugly: A meta-analytic review of positive and negative effects of violent video games. Psychiatric Quarterly, 78(4), 309–316.
- Ferguson, C. J., Garza, A., Jerabeck, J., Ramos, R., & Galindo, M. (2013). Not worth the fuss after all? Cross-sectional and prospective data on violent video game influences on aggression, visuospatial cognition and mathematics ability in a sample of youth. Journal of Youth and Adolescence, 42(1), 109–122. Retrieved from http://static1.wikia.nocookie.net/__cb20131108072659/the-kings-hand/images/a/ae/Not_worth_the_fuss.pdf.
- Ferguson, C. J., & Kilburn, J. (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(2), 174–178. Retrieved from http://www.igea.net/wp-content/uploads/2010/03/Ferguson-Kilburn-2010.pdf.
- Gentile, D. A., & Gentile, J. R. (2008). Violent video games as exemplary teachers: A conceptual analysis. Journal of Youth and Adolescence, 37(2), 127–141. Retrieved from http://www.psychology.iastate.edu/~dgentile/pdfs/G2_Exemplary_Teachers_in_press.pdf.
- Johnson, D., Jones, C., Scholes, L., & Carras, M. C. (2013). Video games and wellbeing: A comprehensive review. Sydney: Young and Well Cooperative Research Centre. Retrieved from http://www.youngandwellcrc.org.au/document/ea0e9511fce02b8be23990_07ef7fc4c7/Videogames_and_Wellbeing.pdf.
- Kutner, L., & Olson, C. (2008). Grand theft childhood: The surprising truth about violent video games and what parents can do. Simon and Schuster.
- Lemmens, J. S., Valkenburg, P. M., & Peter, J. (2011). Psychosocial causes and consequences of pathological gaming. Computers in Human Behavior, 27(1), 144–152.
- Möller, I., & Krahé, B. (2009). Exposure to violent video games and aggression in German adolescents: A longitudinal analysis. Aggressive Behavior, 35(1), 75–89. Retrieved from http://www.vfa-ev.de/fileadmin/File/Moeller_Krahe_AB2009.pdf.
- Sherry, J. L. (2004). Flow and media enjoyment. Communication Theory, 14(4), 328–347. Retrieved from http://cht.tcm.ncku.edu.tw/attachments/053_96_Flow%20and%20Media%20Enjoyment.pdf.
- Sherry, J. L. (2007). Violent video games and aggression: Why can't we find effects? In R. W. Preiss, B. M. Gayle, N. Burrell, M. Allen, & J. Bryant (Eds.), Mass media effects research: Advances through meta-analysis (pp. 245–262). Mahwah, NJ, US: Lawrence Erlbaum Associates Publishers.
- Shibuya, A., Sakamoto, A., Ihori, N., & Yukawa, S. (2008). The effects of the presence and contexts of video game violence on children: A longitudinal study in Japan. Simulation & Gaming, 39(4), 528–539.</sup>

Answer 6

OK, getting over the irony of an ex-action-movie star trying to make an argument against violent video games...

The gamer bias in me wants to say that's silly! However the evidence is strongly in favor of violent video games predicting violent behavior in kids. The American Academy of Pediatrics is an organization I generally look to for advice on raising my kids, and they agree as shown in this study: http://pediatrics.aappublications.org/cgi/content/abstract/122/5/e1067

That being said, I grew up in a time when everything was blamed for any perceptible increase in violence, from rock music to violence on TV. When I see the studies on video games my initial response is to roll my eyes and start the next round of Call of Duty. Most studies deal with kids who play hours of violent video games a day and don't deal with moderate gaming, or address it as in the study I linked to above: game in moderation.