200 university academics have criticized a report linking video games to violent behavior. They say the study from the American Psychological Association failed to properly assess the credibility of its source material.

The APA recently released an initial report of a task force made up of seven scientists. They did not carry out a study themselves. Instead they used two sources. Firstly they looked at four meta-analyses (studies of multiple studies) published between 2007 and 2010. Secondly they examined 31 studies published since 2009, selected from a pool of 131 studies that were whittled down using a checklist for relevance and statistical reliability.

The APA’s report concluded that there was a “consistent relation” by which violent video game use led to increased aggression and decreased empathy. However, it said that violent games were only one risk factor and that it was a combination of factors that led to aggressive and violent behavior.

Now an open letter from academics says the report could have several flaws:

• While the report ultimately derives from multiple studies, it may be missing the findings of studies that failed to show a link and thus weren’t published, or of studies which tried and failed to replicate previous findings.
• Combining multiple studies may exaggerate small supposed correlations that don’t necessarily stand up. For example, a “gamers = violent” conclusion might be too simple and ignore a more complex explanation such as “gamers are more likely to be male; men are more likely to be violent.”
• The way people express violence in laboratory settings might not accurately reflect behavior in the real world.
• While meta-studies have their uses, it isn’t necessarily correct to assume that lots of studies showing weak evidence of a violence-gaming link can combine to produce a strong evidence base.

The academics also note that overall violence among youths has fallen during the period in which video gaming has become more popular.