The effect violent video games have on real-world behavior has long been a hotly debated topic. Some argue there is assuredly a link between playing violent video games and increased levels of aggressive behavior, while others maintain that games themselves don't cause violence, but are rather one prominent risk factor for violent real-world behavior. Now, another study has been published, this one claiming that there is no evidence to support the notion that violent video games lead to increases in real-world violent crimes.

The study, Violent Video Games and Real-World Violence: Rhetoric Versus Data, was conducted by researchers at Villanova University and Rutgers University, and was published recently in the Psychology of Popular Media Culture. Through four unique data analyses, the researchers looked at how popular video game trends, like annual and monthly video game sales, as well as Google Trends keyword search volume, compared to real-world crime rates.

"Finding that a young man who committed a violent crime also played a popular video game, such as Call of Duty, Halo, or Grand Theft Auto, is as pointless as pointing out that the criminal also wore socks"

What the researchers found surprised them. If it's true what some researchers are saying, that playing violent video games might lead to increases in real-world violence, you would expect this new study to bear that out. But it was not the case. In fact, the research showed that there is no evidence that violent video games are positively correlated to real-world crime rates in the United States.

Need the short version? The research is summed up thusly:

"Annual trends in video game sales for the past 33 years were unrelated to violent crime both concurrently and up to four years later. Unexpectedly, monthly sales of video games were related to concurrent decreases in aggravated assaults and were unrelated to homicides. Searches for violent video game walkthroughs and guides were also related to decreases in aggravated assaults and homicides two months later. Finally, homicides tended to decrease in the months following the release of popular M-rated violent video games."

"Finding that a young man who committed a violent crime also played a popular video game, such as Call of Duty, Halo, or Grand Theft Auto, is as pointless as pointing out that the criminal also wore socks."

It's a fascinating finding, even if it does have some limitations (like most major studies). I recently had the chance to speak with one of its authors, Patrick Markey, an associate professor of psychology at Villanova. You can read the study for yourself here, and see my full conversation with Markey below.

What inspired you to launch into this research in the first place?

Many people in the media and even my fellow researchers have linked violent video games and other forms of media to real acts of horrific violence. For example, in testimony before the U.S. Senate Dr. Craig Anderson argued that '... high exposure to media violence is a major contributing cause of the high rate of violence in modern U.S. society.' More recently, in the pages of Pediatrics Dr. Strasburger claimed that '.. an estimated 10% to 30% of violence in society can be attributed to the impact of media violence.' However, these statements are based on research that has not actually examined serious acts of violence--most previous studies either examined proxy assessments of aggression--giving a person spicy hot sauce, exposing a person to an irritating noise--or self-reports of hostility. We wanted to see whether such findings generalize to homicide and aggravated assault rates.

Your research shows there is no evidence to support a link between violent video games and real-world violent crime in the US--do you think you'd find similar results in other regions?

There is no reason to believe the effects would be any different. However, this is an empirical question and we hope future researchers might consider examining it.

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What were some of the most surprising findings of your research?

By far the most surprising finding was that violent video games were negatively related to aggravated assault and homicides. This really surprised me. However, after this discovery we replicated this finding examining violent movies. It turns out, like violent video games, the popularity of violent films is inversely related to violent crime.

It seems to me like a major limitation of this study is that it only accounts for one risk factor for violent behavior--violent video games. What's your response to this?

Obviously correlation does not imply causation so one needs to always be cautious when interpreting ecological data--this same issue applies to whether we are examining links between autism and vaccines or smoking and lung cancer. However, in this study we did not simply look at the relations between violent video games and crime. We also accounted for various trends in the data which might explain this relationship. For example, we eliminated seasonal trends which remove any extraneous results which might have occurred because video game sales tend to be high in the winter and crime tends to be high in the summer. We also removed linear trends which might occur if violent crime is generally going down and video game sales are generally increasing. We also examined various predictors (video game sales, searches for violent video games, release dates of violent video games) both annually and monthly. Even with all these issues considered the same result emerged--violent video games were negatively related to violent crime.

"I think the biggest 'take home' of this study is that violent video games were not related to increases in violent crime--not even a little" -- Professor Markey

Why did you decide to conduct your study using the methods that you did? What other possibilities were considered?

Ecological studies, like this one, are probably the best way to examine events like homicides. Such a--fortunately--rare behavior cannot really be studied in the laboratory.

Some of your results suggest that there is actually a decrease in violent crime in response to violent video games; are you saying here that playing violent games might potentially make the world a safer place?

This is where we need to be careful--otherwise, we run the risk of being sensationalistic. I think the biggest 'take home' of this study is that violent video games were not related to increases in violent crime--not even a little. However, if we assume that violent video games are actually related to decreases in violent crime, we can speculate about why this might have occurred. It is possible that violent media might reduce severe acts of violence because it effectively removes violent individuals from other social venues where they might have otherwise committed a violent act. In other words, violent individuals might attend a movie, watch television, or play a video game instead of engaging in other activities--going to a bar, socializing on the streets---that are more likely to result in a violent altercation.

"There is no evidence that, even in the laboratory, violent video games have a different effect on mundane acts of aggression than other forms of violent media" -- Prof. Markey

Was it difficult for you when conducting this study to separate, as you say, scientific results from scientific conjecture? How did you overcome that?

As scientists--and reporters--we need to use caution when generalizing results from laboratories and questionnaires to things like violent crime rates. In a similar manner, restraint is warranted when research collected in university laboratories is used to explain the idiosyncratic behavior of a specific individual--e.g., the Aurora, Colorado shooter, James Holmes. Given that the public, media, and lawmakers tend to be concerned about trends in violent behavior and specific acts of violence, it is understandable why some researchers might be tempted to make sensationalistic claims based only on laboratory and questionnaire research. However, it is important for us, as researchers, to be aware of the tentative nature of such claims and consistently acknowledge these limitations.

Your study is not the first to reach this conclusion, yet video games continue to be singled out as movies, books, and other mediums are often overlooked in the popular discussion on the role violent video games might have on behavior. Why do you think this is?

There is no evidence that, even in the laboratory, violent video games have a different effect on mundane acts of aggression than other forms of violent media--the 'effect sizes' found in studies are similar regardless of the media examined. However, you are correct that violent video games are always the focus. Probably the best explanation for this is what Dr. Chris Ferguson calls a 'Moral Panic.' That is, people who are the leaders of a society often blame things which they do not value for societal ills.

In the wake of the Sandy Hook shooting, many lawmakers proposed new measures against violent video games, though none have really panned out. What effect do you think your research could have on future legislative action?

As a researcher my job is to present the science and let others figure out what should be done with it. My hope is simply that others consider these data whenever a person suggests violent video games are 'a major contributing cause of the high rate of violence in modern U.S. society,' or that 'an estimated 10% to 30% of violence in society can be attributed to the impact of media violence.'

"I do hope results from studies like ours will cause researchers to reevaluate their previously held beliefs about violent video games" -- Prof. Markey

As I understand it, your study was conducted prior to the arrival of the Xbox One and PlayStation 4, new consoles from Microsoft and Sony that offer better graphics than their predecessors. Do you think that as time goes on and games become far more life-like and fully realized, we could see a different trend than the one you observed?

During each new generation of game consoles there has not been a noticeable change in violence. Additionally, research in laboratories has not found that more 'realistic' graphics have bigger effects of even mundane acts of aggression. So it is unlikely the next generation will alter the trends observed in the study.

What are you looking at for further research on this topic?

No idea--maybe your suggestion about looking at different countries.

You have been studying games and violence for a long time now. Over the course of those years, how has your perception of the video game industry shifted?

I don't really have a strong opinion about the game industry itself. They make a product and my job is basically to figure out if that product might be harmful. However, I do hope results from studies like ours will cause researchers to reevaluate their previously held beliefs about violent video games. After all, we all want pretty much the same thing. We want to uncover the 'truth.' We want science, not sensationalism, to inform policies concerning violent video games. We want to protect others from any threats posed by violent video games, but we do not want violent video games to distract from the more important causes of horrific acts of violence.

Analyses featured in this study included data from GameFAQs, which is owned by CBS Interactive, the parent company of GameSpot.

Eddie Makuch is a news editor at GameSpot, and you can follow him on Twitter @EddieMakuch