Violent video games: What are the effects?

© 2019 Gwen Dewar, Ph.D., all rights reserved

Do violent video games have negative effects on kids?

The question has been debated for decades, and it's still controversial. One of the central problems is establishing causation in the absence of randomized, controlled experiments that track long-term outcomes. We simply don't have that kind of information.

Instead, most studies fall into one of two categories:

  • Experimental studies that measure immediate effects. If we randomly assign people to play violent games, do they behave differently immediately afterwards?
  • Correlational studies that compare fans of violent games with other people. Are devoted players of violent video games more aggressive or violent in real life? 

For both types of study, researchers have reported links between game play and aggression, and that's worthy of our concern. But important caveats apply.

1. The short-term effects are just that -- short-term effects that appear to wear off after a few minutes.

It isn't clear if or how they might related to long-term behavior problems.

2. While the correlations between long-term game play and aggression is real, the effect size is small, and hard to interpret. 

For instance, it's likely that some of the effect reflects the fact that aggressive individuals tend to seek out aggressive entertainment. It's not clear that long-term exposure to violent games makes players more likely to engage in physical violence in the real world. 

3. What do we have in mind when we refer to a "violent" video game? There are different types and degrees of violence, and it's reasonable to think that these differences may have different effects on players.

Studies often lump together many different kinds of games, which makes it hard for us to know which, if any, games are especially problematic. We need more research to answer this question.

4. When it comes to child outcomes, there is much more to concern us than whether or not games make kids more physically violent.

It might be that violent games don't promote physical violence per se, but instead have harmful effects on mood. Are some games too stressful or disturbing? It's also possible that certain violent games encourage kids to internalize negative stereotypes about race and gender. And there's reason to think that games featuring gun violence could encourage children to engage in dangerous behavior with real guns.

So the research doesn't lend itself to easy conclusions, nor does it favor extreme views.

On the one hand, skeptics are right to argue that the evidence for long-term outcomes is either inconclusive, or suggestive of a small effect. In particular, there is no convincing evidence that playing these games leads kids to commit serious acts of violence.

On the other hand, experiments indicate that violent video games do tend to switch players into a more aggressive mode, at least temporarily. This contrasts with prosocial games that tend to make people behave with more kindness.

And many important questions remain to be answered -- particularly for children, who aren't typically the subjects of experiments on the effects of violent video games. 

In the end, the takeaway is that parents are well-advised to preview games, and make sure the content is appropriate for their children, and consistent with their values. 

Here is a more detailed look at the evidence.

The short-term effects of violent video games on social behavior

Torture scene, GrandTheftAuto 5 - screenshot by BagoGames

A number of experiments show that adults feel more hostile after playing violent games--especially games that simulate real-life situations (Bartlett et al 2007; Bartlett and Rodeheffer 2009; Bartlett et al 2009).

There is also evidence that playing violent games can make people behave more aggressively immediately afterwards.

For example, in one experiment, researchers randomly assigned 77 adult volunteers to play either a violent video game or non-violent alternative. Then, after 20 minutes, the researchers gave players an opportunity to blast a stranger with loud noise. Players who'd spent time with the violent game chose longer, louder blasts (Hassan et al 2012).

Other experiments have found that the effects depend on personal traits, like the propensity to experience anger. Anger-prone people may be more likely to respond to video game violence with post-game aggression (Englehardt et al 2011). There is also evidence that playing an aggressive hero results in less post-game aggression than playing an aggressive villain (Sauer et al 2015).

Do children respond similarly? Researchers haven't performed identical experiments on kids, so we don't know if they would blast strangers with distressingly loud noises. 

But in one study, boys who had been assigned to play a violent video game behaved differently afterwards. During a free play session, they were rated by their peers as more aggressive. The same game experience did not appear to affect peer ratings of the behavior of girls (Polman et al 2008).

In another study, researchers randomly assigned some kids to play a violent video game, and other kids to play a nonviolent game in which player takes on the role of a family helper.

Immediately after playing their video games, kids were given the opportunity to help or hinder a peer from earning money. Kids who'd just played the helping game chose to be helpful. Kids who'd just played the violent video game made choices that were more antagonistic (Saleem et al 2012).

There is also research suggesting that video game violence can have a short-term effect on a player's response to people in trouble.

In an experiment on college students, researchers Brad Bushman and Craig Anderson assigned participants to play either

  • a game featuring violent combat (e.g., Duke Nukem or Mortal Kombat)
  • a nonviolent video game with little or no social content (e.g., Glider Pro, 3-D Pinball)

After 20 minutes of play, the participants were left alone in a room while they filled out a lengthy (and bogus) questionnaire about video games.

Then researchers played a little trick: They staged a fake fight in the hallway outside using professional actors. The fight was loud and disruptive. Actor 1 was heard to threaten Actor 2. There was a crashing noise. Someone kicked the door.

And study participants also heard this dialogue:

Actor 2: (groan)

Actor 1: Ohhhh, did I hurt you?

Actor 2: It’s my ankle, you bastard, it’s twisted or something…I can’t even stand up!

Actor 1: Don’t look to me for pity.

Actor 2: You could at least help me get off the floor.

Actor 1: You’ve gotta be kidding. Help you? I’m outta here [slams the door and leaves].

Participants didn’t know that the fight was phony. How did they react?

It depended on which video game that had been playing.

People who had been playing violent games were more likely to pretend they didn't hear the fight. When they did acknowledge the fight, they rated it as less serious and they took longer to help the victim (Bushman and Anderson 2009).

Other experiments show that prosocial games have the reverse effect, which you can read about here. So it seems possible that games can alter our responses to people in the real world -- at least for a short time.

But the emphasis is on "short," because these experiments don't tell us about long-term outcomes. In fact, research suggests these short-term effects wear off within ten minutes (Bartlett et al 2009). What about the long-term?

Do violent games contribute to long-term behavior problems?

Christopher Ferguson has argued that the case against long-term effects is weak (Ferguson 2007; Ferguson 2015).

He notes that published experiments have tested only short-term effects, and there haven't been any experimental tests of the long-term effects of video games.

Some observational studies—which tracked the same kids for many months—have reported correlations between gaming and aggression. But of course we have to be cautious about interpreting these studies. It's likely, for instance, that aggression makes people more interested in playing violent games.

Indeed, a study of kids in Belgium and the Netherlands found that boys who were rated as less empathic and more aggressive were especially attracted to violent video games (Lemmens et al 2006). And a study of Korean youth found that aggressive and narcissistic personalities were more likely to become addicted to online games (Kim et al 2008).

So maybe the link between aggression and violent video games merely reflects the fact that aggressive people are more likely to seek out violent content.

To test this idea, Ferguson has conducted several long-term studies that attempt to control for personal differences in aggression. None of them have linked exposure to violent games with acts of real-world violence (Ferguson and Wang 2019; Ferguson and Olson 2014; Ferguson et al 2013; Ferguson 2011).

But other researchers have gotten different results. Tracking children and teens in two countries -- Japan and the United States -- Craig Anderson and his colleagues found evidence that kids who play violent video games are more likely to admit to aggressive behavior in the real world. This was true even after controlling for initial levels of aggression (Anderson et al 2008).

And researchers in Germany found that teenagers who spent more time playing violent video games at the beginning of a study were more likely to have committed acts of physical aggression 30 months later. By contrast, teenagers who were more physically violent at the beginning of the study were not more likely to play violent video games 30 months later (Möller and Krahé 2009).

In other words, playing violent games was a predictor of later aggression. But being aggressive wasn't a predictor of playing violent games.

Ferguson takes issue with such studies, arguing that self-reports aren't the same as objective measures of aggression and that—in any case—the effects reported by the studies are rather weak, explaining no more than 2% of the difference between aggressive and non-aggressive youth. (Ferguson 2007).

In fact, when Ferguson conducted a meta-analysis of 101 published studies, he found a statistically significant "yet very small effect on aggressive behavior" for both video games in general and violent video games in particular (Ferguson 2017).

In his latest study, he found an effect that was so weak, it would take "27 h/day of M-rated game play to produce clinically noticeable changes in aggression (Fergus and Wang 2019).

Thus, if violent video games have an impact on the development of aggressive behavior problems, the effect does not appear to be important. Not as measured by these studies. There isn't persuasive evidence that video game violence causes kids to commit acts of serious violence in the real world.

But that doesn't mean there are no negative effects. Ferguson's own research acknowledges that something is there.

One explanation for the "very small effect" observed across studies is that only a subset of kids are at risk. Another possibility is that only a subset of games labeled as "violent" are problematic. As Ferguson notes, part of the trouble is that "violent" is a vague term that's been applied to games as different as World of Warcraft, Call of Duty, and Pac Man (Ferguson 2015).

What about gun violence?

Games featuring guns may make children more curious about guns. Could this lead kids to engage in dangerous behavior in the real world?

Justin Chang and Brad Bushman tested this in a recent experiment on 242 American children (8-12 years old). Each participating child was randomly assigned to play one of three different Minecraft games with a peer:

  • Kids in the gun condition played a game that featured monsters they could kill with guns.
  • Kids in the sword condition faced monsters, too, but no guns. They could kill monsters with swords. 
  • Kids in the non-violent condition experienced an entirely non-violent game. There were no monsters, and no weapons.

Then, after 20 minutes of Minecraft play, kids were subjected to a bit of subterfuge.

An adult experimenter would take the children to a new room, a room with a cabinet of toys and games (like Lego blocks and Jenga). The adult told the kids they would be left in the room for 20 minutes, during which time they were free to play with any of the toys and games.

The adult didn't explain that the kids would be monitored by a hidden camera. And the adult didn't mention that there were handguns in the bottom drawer of the cabinet: Two real, disarmed, 9-mm handguns. 

What happened?

The kids, who were tested in pairs, almost always found the guns. About half the kids touched a gun, and one third of them pulled the trigger at least once. In these respects, kids didn't differ by condition. 

But there was a worrying outcome that did differ by condition -- whether kids pulled the trigger while pointing the gun at someone.

Compared with kids in the non-violent condition, kids who had played the gun version of Minecraft were 18 times more likely to pull the trigger at either themselves or their companion.

By contrast, kids who had played the sword version of Minecraft did not show an increased likelihood to pull the trigger at a person (Chang and Bushman 2019). 

And other worries?

Future research -- employing the best-available controls -- may enlighten us. Meanwhile, attentive parenting is warranted. 

Rating systems exist to help parents assess whether a game is appropriate for their children. But games rated as age-appropriate may nonetheless contain content that kids find disturbing (Haniger and Thompsen 2004; Thompson and Haniger 2001), or that adults recognize as sexist or sexualized (Bègue et al 2017).

So it pays to take a closer look.

More information

For more information about research on video games, see these pages. In addition, parents can find detailed reviews of specific games on Common Sense Media.


References: Violent video games and parenting

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image of video game controller from a larger image by Landin Hollis / flickr

screenshot of Grand Theft Auto V by BagoGames / flicker

image of child in silhouette by Sudhamshu Hebbar / flickr 

Content last modified 8/9/19