Cognitive Daily


Carmageddon 2 (source: Gamespot) is a gory racing game where players control drivers with names like “Max Damage” as they tear through city streets mowing down pedestrians and forcing competitors into bloody collisions. The game settings can be adjusted so that running down innocent bystanders actually increases a player’s point total. Surely, if there’s any video game that might raise a parent’s ire, Carmageddon 2 is one of them.

Studies have shown that violent video games are more likely than non-violent games to induce aggressive behavior, even after very short playing sessions. But more recent research (by Dmitri Williams and Marko Skoric) has suggested that violent game play does not always lead to aggression. In Asheron 2, Williams and Skoric note, players are not allowed to attack other humans, only monsters, and they must cooperate with other players to succeed. Perhaps by limiting violent actions and rewarding cooperation, Asheron 2 discourages aggressive behavior. Other studies have shown that people who watch violent television shows where the perpetrator is punished are less aggressive than those watching violent TV behavior that is rewarded.

Nicholas L. Carnagey and Craig A. Anderson wondered if punishment and reward are keys to whether violent video games lead to real-world aggressive behavior. Video games are different from TV, and players might become frustrated if they are punished for violence, leading to more real-world aggression. Noting that no study had previously controlled the punishment and rewarding of violence in video games, they designed a study to do just that.

Carnagey and Anderson utilized Carmageddon 2’s customizability to create three study groups: in one group, participants were rewarded with points for killing innocent pedestrians and smashing into opponents; in a second group, they were punished for it; in a third “non-violent” group, pedestrians were removed from the game entirely and computerized opponent cars were programmed to behave passively.

Participants played the game for just 20 minutes, but even in this short time, different game-playing behavior was observed. Players who were rewarded for violence typically killed 80 pedestrians; those who were punished killed fewer than a third as many in the same period of time. Next the researchers studied post-game aggression in three different ways. First they measured aggressive affect. This was done by giving the State Hostility Scale, in which participants rate their feelings in categories such as anger, hostility, and aggravation, on a simple 1-to-5 scale. For a second group of players, they used a Word Fragment Task, where participants complete as many words as possible in 5 minutes. For example, “K I _ _” could be completed as “kiss,” “kill,” “kick,” or “kilt.” Those who used more aggressive options in this task were rated as having more aggressive cognition.

Finally, a third group was tested for aggressive behavior. Participants were led to believe that they were competing against another participant playing a different game in an adjoining cubical (after the experiment, participants were debriefed and the true purpose of the study was explained). They were cleverly primed to dislike this “player” by being asked to write an essay expressing their opinion on a controversial issue—abortion. After they completed their essay, the experimenter took it and told them their competitor was going to “grade” the essay. Then the participants graded the fake competitor’s essay, which was chosen from two pre-prepared essays, so that participants always saw a paper expressing the opposite opinion from their own on the topic.

They played one of the three versions of Carmageddon for 20 minutes, and were given their “graded” essay, marked by the fictitious competitor with the lowest possible grade and indicating that “this is the worst essay I have ever read!”

Now, they were asked to perform a competitive reaction-time test. If a player won, he or she got to choose the “penalty” for their new nemesis (who they believed to be either a baby-killer or a woman-hater and also a poor judge of writing ability). The penalty was a painful noise played through headphones. Players chose before each test how loud the noise would be, and how long it would be played. In reality, the “test” was rigged so that the participant won 13 times and the non-existent “competitor” won 12 times, inflicting a noise blast of a pre-selected length and intensity. When the participant won, he or she got to get “revenge.” Even though the real participants weren’t really hurting anyone, they certainly believed they were. Players who gave louder and longer penalties were clearly behaving more aggressively than those who gave less extreme penalties.

Now let’s take a look at the results for these three different measures of aggression. The different rating systems have been converted into z-scores, which is a way of placing numerically different scores onto a similar scale so that they can be compared. In each case, a greater z-score corresponds to more aggressive behavior or attitude.


It’s clear that the version of Carmageddon 2 that rewarded violence led to the most aggression. Though the difference between the reward/punishment scores was actually not significant in the aggressive affect measure, it was in the other two measures, and in every case, the version that rewarded violence led to more aggression than the nonviolent version. However, it’s important to realize that the negative z-scores in this graph do not suggest that a nonviolent game leads to decreased aggression—this is an artifact of the way z-scores are computed. All we can say from this graph is that playing nonviolent games leads to less aggressive behavior and attitudes than playing violent games.

Many defenders of violent video games argue that they are in control of their own actions, and that video games should not be restricted due to statistical correlations between playing violent games and aggression. In this, they may be correct, but that does not invalidate the results of this study. Playing games that reward violence leads to more aggressive behavior and attitudes than playing games which do not reward violence. Even if this knowledge doesn’t reduce the number of people playing violent games, the knowledge can be used in other ways.

For example, I talked to my son Jim about the study. He’s a typical 13-year-old who plays games that, while not as gory as Carmageddon 2, certainly offer their share of violence. When I pointed out to him that he is more likely to behave aggressively after an especially vicious gaming session, it was difficult for him to disagree. After he figured out that I wasn’t going to take away his favorite games, he even admitted that it was a handy bit of knowledge to have.

Carnagey, N.L., & Anderson, C.A. (2005). The effects of reward and punishment in violent video games on aggressive affect, cognition, and behavior. Psychological Science, 16(11), 882-889


  1. #1 Justin H.
    November 23, 2005

    well i think violent gaming is ok because of the fact crime rate goes down 5% every time some one buys a violent video game. its not like im really going to go out in the middle of a street and uses an rpg on civillians to get their cash(gta series). i think soe parents are stupid for letting their children get an
    M RATED GAME, just because it looks like an ok game on the cover doesnt mean that there wont be a violent, sexual,or scary suprise moment in the game. then after their kids tell them about that special part parents decide to go public and sew someone.hope u all listen because this is good info to think about…

  2. #2 Tommy
    November 24, 2005

    Is it safe to assume the same for violence in other media? Or is the interactive aspect of a game a katalyst?

    I find the study very interesting, but it’s also safe to assume that after a (short?) period not playing the game, people won’t be aggressive. Also the persons were more aggressive but was the worst effect the way they chose their words? I mean their are a lot of reasons people can be more aggressive then they normally would be due to stress.

    I would like to have seen the same test but with a group playing a sport like soccer or tennis, or martial arts. My feeling is that the outcome won’t be much different.

  3. #3 Dave Munger
    November 24, 2005


    It’s not safe to assume anything other than the results of the study. You’re right that many other activities may result in aggressive behavior—it’s a point that Steven Johnson has made more than once. However, those studies have not been conducted—what we can discuss here is the results of this study.

    The study shows more than the poor word choice of participants—participants believed they were inflicting pain on others, which by any definition is actual aggressive behavior, not word choice.

    I, too, would be interested to learn more about how participating in sports leads to aggressive behavior. One thing the Carmageddon 2 study might point to is the rewarding/punishment of violent behavior. Soccer players are penalized for actions likely to hurt other players. Even in the martial arts, there are penalties for low blows, etc., so perhaps competing in these activities is most like the “violence punished” condition in the Carmaggedon 2 study.

    Based on my own intuition after playing in intense soccer games or skiing, I’ve typically been in a different mood than I am after playing intense video games. I feel more aggressive after playing video games compared to sports, where typically I’m so wiped out I can’t imagine hurting anyone. A more likely analogue is how I feel after driving in bad traffic: I’ve got plenty of pent-up aggression after doing that!

    But we won’t know for certain which activities lead to more aggressive behavior until we do the studies. For now, most of these studies focus on violent media and video games.

  4. #4 Kevin Brubeck Unhammer
    November 24, 2005

    It’d be really interesting seeing a long-term study on the effects of video game violence, especially one that would manage measuring any differences in aggressive behaviour a long while after the subjects have stopped playing, and perhaps with other groups of subjects playing sports or martial arts. Of course, getting someone to commit to a study like that for very long might be really hard… especially since they’d have to be randomly assigned (to avoid all the violent people choosing one thing over another), and subjects might have to refrain from doing what the other groups did.

  5. #5 dr Howard
    November 27, 2005

    It is also important to realize how researchers define violence. The classic TV violence study had children hit blow-up punching bags (bobo dolls). They claimed the increase in punching proved an increase in violence. Conversely I claim that violence is an act against another person. When kids keep their aggression in the imaginary play-world of dolls and games it is not violence. If I hit you that is assault and I go to jail, if I hit a doll or if I hit L-L-R on the control I am keeping my aggression in the imaginary world and not the real physical world of people. Kids need an imaginary place to learn about aggression and violence; and games have proven over the years to very successful in this task. 200 years ago your average kids blew up stuff with real guns. While non-competative sports has it place. Many kids love aggressive contact sports, and a bloody nose is just a minor inconvenience and not a lawsuit. I also propose that many of the Hyperactive kids need physical and aggressive outlets, but as adult we tend to ban such activities. Now as a child I was not an athelete and preferred reading, but I was able to see most children needed some means to express their violence and aggression. So when Batman hits the thug and video car crashes it is resides in the imaginary world. Where do you live>>>>

  6. #6 Kamaria
    November 29, 2005

    Honestly? I felt more violent after I saw Fight Club then when I beat Ratchet and Clank. (A video game where you blow things up.)

  7. #7 Dave Munger
    November 30, 2005


    The point about video game addiction is a good one. There have been several studies on game addition, and we’ll try to report on the more recent work in the near future.

  8. #8 Zane
    November 30, 2005

    Apparently you all have no idea upon anything if you really want to get deep into games…A better focus would be addiction. I am an avid PC gamer and seriously instead of violence it should be focusing more and more on the endless hours that people put into games and the addiction of games. I have played Everquest for around 2 years and also another game on the internet Runescape for almost 5 years…Also I’ve played all of the Grand Theft Auto series. Honestly I’d say I spend many hours of my day when not in school or not working playing games. Honestly if anything you all need to focuse on more of the addiction then the violence in the game. Just pointing this out to you all who are all too blind to see the bigger problem is addiction thank you for the time.


  9. #9 Eric
    November 30, 2005

    Justin H. writes, “well i think violent gaming is ok because of the fact crime rate goes down 5% every time some one buys a violent video game.” That’s a fact, huh? Too bad these games aren’t popular, because if they could only sell 100 copies, crime would be 0.6% of what it currently is (0.95^100).

    dr. Howard writes, “Conversely I claim that violence is an act against another person. When kids keep their aggression in the imaginary play-world of dolls and games it is not violence.” You throw out your theories, but we have some real data in this summary. Here they use the term aggression, not violence, and they measure it three different ways, one of which is where the participant believes s/he is acting aggressively towards another human.

    dr. Howard further writes, “I also propose that many of the Hyperactive kids need physical and aggressive outlets, but as adult we tend to ban such activities.” Yes, the old steam engine theory of human psychology. Pressure builds up, and an outlet valve needs to be opened up.

    Thanks for telling us you’re a “dr.”, but you don’t get any free credibility unless you tell us whether it’s a PhD, MD, JD or whatnot, which area it’s in, and which institution granted it.

  10. #10 Sean Choate
    December 2, 2005

    This study does not acheive what it sets out to do. It compares a violent vido game in which one element of aggressive behavior is punished to a game where all aggressive behavior is rewarded. One will surely not get a reduction in violent behavior as long as the primary objective of the game still allows the player to blow other cars off the road. I saw very little discussed in the .pdf of the study about what kinds of violence were allowable and such. It seemed to black-box the “game” and use it to infer a general result.

    If one were to truly make a study out of this, two different games would probably be needed. Sure, that leads into some very muddy area when one considers variables, but all variable that change from an aggressive game to a non-aggressive game are dependent on that very shift.

    Another point left out of this study was one of frustration. Very often in B-rate games (which Carmageddon most probably is) there is a discrepancy between the players’ perceived input and the output of the game. That is, the play control might not be great. And that has lead to more aggression from my experience than any head-shots. I’ll hear the excuse in Tetris as often as in Halo: “My controller…&etc.” In these cases, the player is frustrated by the difference in their perceived skill and their ability to perform in the virtual world. That is maddening, and the resultant threat that person perceives does more to trigger an aggressive reaction than a virtual head shot.

    Finally, aggression was triggered in one test through peer reviews and a situation in which the participants are lead to believe that their opponent has marked them poorly. What relevance does this have on video games? It may be true that this is a common element of many aggression tests, but it seems thrown in to this study more for effect that for procuring a truthful and result.

  11. #11 Brian Fassl
    December 5, 2005

    I aggree with what Justin said about how some parents don’t pay attention to the ERSB rating on the game. I mean really its up to the parents to decide whats too violent or whats not. I myself am a hardcore gamer, i play lots of games that are considered violent, but do i feel more violent after playing them, no. I really think that the media is blowing this way out of proportion, i mean if its decided that video game violence does increase violence in the players, then what about tv violence, movie violence, i mean if you punish one thing you gotta punish all of it, but people seem to be reluctant to blame violent tv shows or movies, people and parents always jump right to video games.

    The majority of people that i hear from mostly say, that video games are to balme,or that “this study says
    blah blah blah”, the problem with studies are that the participants are being asked to play on demand, they’re not playing because they choose to. Thats the key mistake of all these studies.

    I mean video games don’t exactly reduce aggressive behaivior but at the same time it doesn’t increase it. Fct is that anyone with half a brain can tell the difference between the real world and the virtual world of video games. People are always saying that people can’t really tell the difference after a while, thats not true. I’ve been playing video games all my life and i can tell the difference. And like i said, anyone with half a brain can tell the difference between the real world and the world of video games. I mean that people who play video games can definetly tell the difference between a game and the real world, same goes for simulated violence. Just because a game is violent doesn’t mean that someone’s gonna go imitate the game in the real world.

    I mean i’m certainly not gonna go imitate a scene from a Zelda game or one from a Metroid game. Thats because i can tell the difference between whats real and whats not; video game violence is really simulated violence, that’s all. And parents and reasearchers are just worried because video games are so addictive and popular.

    Also, right now i’m doing a research paper on the topic of “do video games increase violent tendencies?” so if anyone can point me to some good sites for research i’d appreciate it.

    you can e-mail me with suggestions of sites to look at at, or

  12. #12 Kilowog17
    December 12, 2005

    I too have played video games my ‘entire life’. I’ve always know that the game is simulated and not real, but what I don’t think about is those that are anti – social or mental unstable. Now I’m not saying that a mental health exam should be taken before the purchase of a game, I don’t think that there even is an answer to that.
    With the whole video games lead to violence line, I don’t think that the majority of gamers support that theory. Most people I know that play games are incredibly docile. However when my friends are on XBOX Live… They’re continuously acting like idiots. Swearing and calling each other Jews. Now that’s disturbing. Someone should do a study on that!
    Whenever I’m playing a game, if I get too frustrated… I turn of the console. I don’t throw a $20 controller against the wall like some people.
    I remember being a kid in elementary school, role playing Star Wars with my friends. And then how boring that was. Then we would go to the paint ball field after school and have a blast playing Capture the Flag. Even after getting shot and covered in paint, we were still friends and had no hard feeling about losing. So if actually going out a shooting at each other didn’t affect the 40 of us, and I now that’s a small sample size and relatively biased as well, maybe games are not the sole attributer to violent behaviour.
    What I’m more concerned about, than this violence and video games garbage, is the attitudes of today’s elementary students. It’s not at all uncommon to hear a second grader telling some to go F*CK Themselves. And not to sound like an old maid or anything, those kids usually listen to rap music. Now I’m not saying anything by this, because I listen to rap and rock and almost everything else and I don’t go around acting like an ass in front of people especially teachers. So maybe the problem of rude behaviour and violence is linked to the individuals’ upbringing. I was raise to act intelligently and now act with respect.

  13. […] Den første er en blogg om kognitiv psykologi: Cognitive Daily. Bloggen tar for seg utviklinger og nyheter innen kognitiv psykologi, er velskrevet, og skrives av Greta Munger (professor i psykologi) og Dave Munger (forfatter). De skriver for eksempel om det er større sjanse for at vi legger merke til ting som aktiverer oss, eller om vi bare husker dem bedre og om videospill reduserer aggressiv atferd. […]

  14. #14 Robby
    December 18, 2005

    The thing most people don’t realize is that, with all the violent video game studies, there are non-violent video games. While there are quite a few, and they seem to dominate the market, not all violent games promote violence or have a dominating violent theme. Violence is part of our world and many games bring out reality. Games like Grand Theft Auto subject players to multiple scenes of gratuitous violence, and are rewarded for these actions. But others, such as the Final Fantasy series, while using violence to complete objectives, are not primarily about violent activites. These games are played almost only for the story. Video game developement is an art and people must realize that the best games are, in fact, not violent.

  15. #15 Tim
    January 14, 2007

    The word choice test seems to be the most likely to provide false conclusions. I don’t think someone chooses the word kill because they are any more or less aggressive, but because their most recent experience, in this case playing violent videogames, made that a more relevant vocabulary choice. For instance, if I just listened to a song with “kiss” in the title or watched a romantic movie, I would most certainly be more likely to choose that as my response. So choosing the word “kill” could easily, and more likely in my opinion, be the result of an affect on vocabulary rather than aggression.

    I agree though with the other poster in that addiction is much more of a problem in videogames than aggression.

  16. #16 Eric
    November 13, 2007

    I have to say that although the violent nature of the game might have increased aggression,(for a time) things like having a person to write an essay on abortion then getting a response wholly opposite and rude would drive some people to anger alone. Irritability can be brought out of someone with little effort and can be traced to almost anything.
    The point I am trying to make is that the nature of the tests and the scenarios set up are going to produce aggression in most cases. Only if all the people involved were put through this test, then a test where the participants played a non violent and a violent game and given agreeable test scenarios could the results be truly accurate.
    One of the contributing factors is that in todays society we have lost our basic Christian morals and discipline. Thus respect must first be “earned”, rather than “given”.(i.e. “You’ll have to earn my respect” instead of giving all persons respect until they give you reason not to)
    My parents taught me respect and honor so although I enjoy violent games and movies I am not controlled by them. But more important I would not desire to cause someone pain as revenge for beating me in some game. If someone wants to blame one single thing for violent behavior I would blame parents for not using correct proven discipline (spanking)
    or the government for trying to control things like discipline and media. “We the people” not “We the life politicians” I hope I was clear and to the point(way past the time I should be sleeping) Violent uncontrolled aggression comes from one own mental stability and is the result of bitterness towards a person or circumstances. Also note that aggression under control is called passion. people must be taught to control their emotions not the other way around.

  17. #17 Benjamin
    July 1, 2008

    I played a lot of violent video games in my youth and still do to some extent now.
    As a psychologist, it gets really frustrating to argue with an avid video gamer. First of all, the counterargument is “I would never kill anyone, just because of video games”. That is entirely not the point! The thing is that you become more aggressive. That means that you are more likely to behave in a hostile way towards another person. Hostility can manifest in different ways. For example, when you are critized, you may be less likely to calmly accept this criticism. Yet, you are most likely not aware of it. You are not self-aware that you always question why you reacted in this or that way – you just act. The good old Nisbett & Wilson “Telling more than we know” and lots of research on priming (e.g. John Bargh’s work) and freedom of the will (e.g. Dan Wegner’s work) shows that it is rare that we are aware of the true reasons for our behavior (which, by the way, hasn’t much to do with Freudian psychobabble).
    Additionally, because of violent video games and violent media as a whole, one is more likely to tolerate aggressive behavior. For example, a school kid would be less likely to go between two fighting buddies, even when the fight is getting out of hand (for some papers on that:
    Moreover, I often hear and read that the effect of the games is totally dependant on the upbringing and therefore the only thing is that the parents should take better care of their children. That is true, but it also means that they should be made aware of the impact video games can have, which again justifies this research. Of course, a child with a good upbringing won’t commit any crime because of video games. Again, that is not the point. The point is, that it is harder for any parent to teach their children understanding and empathy, when their mission in GTA IV is “kill the goddamn lawyer”.

  18. #18 Ace of Sevens
    July 5, 2008

    This does bring up interesting questions, such as what if the person they hated was not directly associated with the game, would they respond the same way? (It’s hard to design the experiment to test this without coming off as contrived). This isn’t really a problem with the study, which accomplished what it set out to do, but these kinds of studies never seem to address certain points.

    We are only given an aggregate effect here. Does this affect everyone or does it only effect some people? Is the effect different on different personality types? How about avid gamers? Violence tends to get abstracted in your mind once you are used to the game and scoring a headshot is no different than hitting a home run. The reason gamers get suspicious when these studies are done is that they think it will be a prelude to regulation and/or banning. Considering many of the attempted laws, this is a reasonable fear, though the US courts have held, as I do, that the effect would have to be much, much stronger to trump free speech.

    Of course, the question of whether violent games make people more agressive begs for a comparison point. Violent youth crime has been dropping quite substantially in a period where the newfound popularity of mass media is perhaps the most notable trend in youth culture. Obviously, it’s hard to pick the perfect control that reflects the real world accurately in a lab setting.

    There’s also the question of whether aggression is per se bad. Just off the top of my head, I’d say it’s actually a positive feature when kept in check by rationality. Who gets promotions in the business world?

    Violent games don’t exactly dominate the market. There are quite a few that sell well, but non-violent game are much bigger overall. Look at the Wii. It’s much like the focus on EC comics back in the 1950s. They were never the best selling comics, just the most shocking to people unfamiliar with them, so they got the media attention.

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