Can video games make us more violent or do some players who are predisposed towards aggression seek out certain games?

Because of these concerns, many countries all over the world have video game rating classification systems such as the European PEGI [Pan European Gaming Information] rating system. PEGI has age ratings (i.e., games that are deemed appropriate for those over the age of 3, 7, 12, 16 or 18 years) as well as indicators of what’s in a game (for example, sex/nudity, violence, swearing, gambling, drug use, fear, discrimination). Most countries have systems of self-regulation in place but sometimes are banned by government authorities because of the game content.

In the UK this has included games like Manhunt 2 (because it was excessively violent) and Postal 2 (because of gory violence). Sometimes individual stores will ban the games from being sold (such as Amazon refusing to sell RapePlay).

There are also constant stories where video games have been blamed for copycat crimes (such as games in the Grand Theft Auto franchise, including a teenager in Thailandconfessing to robbing and murdering a taxi driver while trying to recreate a scene from GTA IV). Such stories keep the ‘video game violence’ debate alive. But what does the science say?

Broadly speaking, there are two opposing research camps in the field of gaming studies. There are those who believe their scientific research demonstrates a causal link between the effects of playing video games and subsequent behaviours and those that don’t.

Many experimental (laboratory-based) studies and reviews carried out by Dr. Craig Anderson at Iowa State University and his colleagues conclude that exposure to violent video games is a causal risk factor for increased aggressive thoughts, feelings and behaviour, and a decreased empathy and prosocial behaviour.

Furthermore, some researchers argue that the inherent structure of violent video games limit young people’s abilities to develop perspectives of victims and does not encourage affective sympathy in children, as any negative effects of being harmed or killed in the games are minimised ignored, or even rewarded. Studies carried out by my own research team have also shown that young people who play violent video games report less concern for victims of crime, and attribute more blame to the victims of crime.

In opposition to this, many studies and reviews carried out by Dr. Chris Ferguson at Texas A&M International University and his colleagues conclude that claims made by Dr. Anderson and colleagues are methodologically flawed and fail to show that playing of violent video games has any association with serious aggression, violence, and crime. For instance, there is a lot of correlational evidence that as the sales of video games have increased over the last decade, the rates of serious youth crime have decreased. Furthermore, there may also be important cultural determinants as countries like Japan have high levels of media violence but have low levels of crime.

In fact, nearly all studies that claim the playing of violent video games leads to more anti-social behaviour highlight correlations and not causation. I don’t believe any study has ever demonstrated absolute causality between video game playing and anti-social behaviour.

One of the major problems with all of the research - including all those that have examined the playing of violent video games - is that studies typically fail to take into account all the other types of violence that individuals are exposed to day-to-day, such as violence they see on the news, and violence they see in films and television, and the violence seen in their own lives and local community. Moreover, many academic journals only publish studies that show statistically significant findings, meaning that they are more likely to publish a study that suggests a link between playing video games and aggression rather than those that do not.

Another problem with most published research is that it doesn't follow players over a long period time. In short, most of the research is what we researchers call ‘cross-sectional’ – it only examines players at one particular ‘snapshot’ in time. Furthermore, much of the research has been carried out has been experimental and carried out in non-ecologically valid settings (typically a laboratory). In fact, all of the measures used to assess “aggression” are proxy measures that are not related to actual violent actions (because it is unethical to try and induce actual anti-social and violent acts within a research experiment).

Another problem in evaluating the scientific evidence is that some players may be predisposed towards aggression and seek games like Grand Theft Auto and Call of Duty out. For instance, studies showing that delinquents play more violent video games than non-delinquents don’t in anyway demonstrate cause. Video games may have had an influence in informing how they might have done something and give them ideas, but they are highly unlikely to be the root cause of anti-social behaviour.

If I played Grand Theft Auto all day every day, I really don’t think it would heighten the risk of me becoming aggressive or carrying out crime. Saying that, I'm a father to three screenagers and I don't let them play violent video games. Just because I think the scientific evidence is flawed, doesn't mean there isn’t any effect. It’s that science has failed to demonstrate a conclusive cause. As we researchers often note, absence of evidence is not evidence of absence.

For me, it's not about putting the blame on the game. At best, playing video games like Grand Theft Auto might at best be a minor contributory factor to anti-social behaviour. But it shouldn't be a scapegoat because all individuals have to take some responsibility for their actions.

Professor Mark Griffiths, Director, International Gaming Research Unit, Psychology Division, Nottingham Trent University