Editor's note: Christopher J. Ferguson is chair of the psychology department at Stetson University. He is the author of the novel "Suicide Kings."
(CNN) -- The horrible shooting at Washington Navy Yard adds to the recent litany of mass shootings in the United States. Much attention typically focuses on what we, as a society, might do to prevent similar events in the future. Unfortunately, the line between reasonable reflection and cultural crusade can sometimes be blurred, with activists drawing in shootings to advance their particular axes to grind.
Since the 1999 Columbine massacre, that issue has often been violent video games. So it should come as no surprise that we have already seen some speculation about whether the Washington Navy Yard shooter, Aaron Alexis, may have played violent games.
Earlier this week, an op-ed by Dr. Brad Bushman may have crossed the line from science to advocacy.
I respect Dr. Bushman and understand that he speaks in good faith about his concerns regarding violent video games. Yet, the field he portrays in his op-ed is not one that I recognize. Research linking violent video games to even mild acts of aggression has been, at best, inconsistent and, as the Supreme Court noted in 2011, often methodologically flawed.
That's not to say some good research isn't being done, but it's not possible for the research to clearly link playing violent games to mild aggression, let alone societal violence. Implying that laboratory research conducted with college students, no matter what the outcome, can be generalized to mass shooters is irresponsible.
Even the studies Dr. Bushman refers to are not as clear-cut as he suggests. For instance, in discussing his meta-analysis, he implies that the 136 articles he reviewed on video game violence were consistent in outcome, which, in fact, they were not. He also neglects to mention that, in his own meta-analysis, video game effects dropped significantly when only a few controls were included.
For instance, in his analysis of long-term outcome studies, video game violence effects dropped to nearly zero when simply gender and prior aggression were controlled. Furthermore, at the time his meta-analysis was published, colleagues including John Kilburn and myself expressed concerns in the same journal that Dr. Bushman and his coauthors had neglected to include many studies finding no links between video game violence and aggression in their analysis.
Dr. Bushman also refers to one of his studies suggesting that college students who played an action game were more accurate with a lifelike pistol. He extends this research to imply that mass shooters may be more accurate due to playing video games. This also, to me, seems a considerable overreach. Alexis had actual military training which would seem more relevant than video games, and shooting unarmed civilians typically requires no great feat of marksmanship. It's important to note as well that Dr. Bushman's study is, as of yet, unreplicated.
Dr. Bushman also neglects to mention considerable research that conflicts with his views. For instance, in a recent study my colleague Cheryl Olson and I found little evidence that violent video games had negative influences on children with pre-existing mental health problems. It would seem this study would bear on speculation that some mentally ill individuals may be susceptible to video game effects, so it is curious it went unmentioned.
Contrary to Dr. Bushman's suggestion, violent video games are not a commonality among mass homicide perpetrators. The impression that a link exists is a classic illusory correlation in which society notes the cases that fit and ignores those that don't. When a shooter is a young male, the news media make a fuss over violent video games, typically forgetting to inform the public that almost all young males play violent video games. Thus, finding that a particular young shooter happened to play violent games is neither surprising nor meaningful.
However, we've seen a rash of high-profile gun violence committed by men over the age of 60 (William Spengler, Douglas Harmon, Jimmy Lee Dykes, etc.) in past months. Since these incidents don't fit the common social narrative of the mad gamer, they are simply ignored.
Lastly, Dr. Bushman advocates legal restrictions on violent video game access. However, since the Supreme Court's Brown v EMA ruling (2011), which also criticized much of this research field, such efforts are clearly in violation of the First Amendment.
In a recent appearance on CNN, video game researcher Patrick Markey cautions scholars not to be irresponsible in extending research in our field beyond where it can go. I echo his comments here. In the 1950s, psychiatrists testified before congress that comic books caused not only delinquency but homosexuality because, they claimed, Batman and Robin were secretly gay. We have to be careful not to repeat these mistakes.
The picture that is emerging of Alexis is one common to most mass shooters whether young or old, man or (rarely) woman -- a resentful man full of anger and struggling with mental health problems.
Making big claims about video games contributing to societal violence runs two risks -- damaging the credibility of the scholars who make such claims, and distracting us from real issues such as mental health care reform.
The opinions expressed in this commentary are solely those of Christopher Ferguson.