Addressing the nation after mass shootings on consecutive days left at least 31 dead in Texas and Ohio, President Donald Trump suggested that violent video games — despite a lack of much hard evidence — are partly to blame.

"We must stop the glorification of violence in our society," Trump said. "This includes the gruesome and grisly video games that are now commonplace. It is too easy today for troubled youth to surround themselves with a culture that celebrates violence. We must stop or substantially reduce this, and it has to begin immediately."

Republican Texas Lt. Gov. Dan Patrick made similar remarks in an interview a day after the El Paso attack.

"There have been studies that say it impacts people and studies that say it does not. But I look at the common denominators, as a 60-some-year-old father and grandfather myself, what’s changed in this country? We’ve always had guns, we’ve always had evil, but what’s changed where we see this rash of shootings? And I see a video game industry that teaches young people to kill," Patrick said.

Criticism was swift.

"Video games aren’t causing mass shootings, white supremacy is," U.S. Rep. Alexandria Ocasio-Cortez, D-N.Y., said on Twitter.

"Every country has mentally ill. Every country has video games. Every country has people who don’t pray. Every country has racists. Only America has near-daily mass shootings. It’s the guns," journalist David Frum, a speechwriter for GOP President George W. Bush, posted on Twitter.

Experts say little evidence to link video games to mass shootings

The video game "Call of Duty" is referenced in a manifesto linked to the suspected shooter in El Paso, Texas. But as the New York Times has observed, the manifesto is notable more for its anti-immigrant language; the suspect drove about 10 hours to get to the border city, police say.

We looked for the most recent research on whether there is a link between violent video games and gun violence. We found little to back Trump’s view.

"There is absolutely no scientific evidence that gaming is linked with mass shootings," Andrew Przybylski, research director of the University of Oxford’s Internet Institute, told us.

"The existing evidence base strongly suggests any effects of gaming, both good and bad, are extremely short-lived and might not extend outside the laboratory context," he said. "If games influence us, these effects are nuanced and certainly do not lead to changes in real-world behavior, as some politicians are claiming."

Here’s a summary of some of the latest research, based on the conclusion.

Przybylski led a study published in February 2019 that was based on interviews with 1,004 British 14- and 15-year-olds and their caregivers. The teens were asked about their gaming and the adults who cared for them were asked about the teens’ behavior.

"Violent video game engagement is not associated with adolescents' aggressive behavior," the study concluded.

Similarly, a 2018 study by Stetson and Florida State University researchers found that the role of violent video games "in the development of youth psychopathology or crime is very little, if any."

Christopher Ferguson, a Stetson psychology professor who was one of the authors of that study, told us: "Across studies, we do not find that consuming violent games contributes to later violent crime. There is no reason to believe violent games contribute, even in part, to mass shooting events."

That’s what a researcher from Harvard University and a researcher from Stanford University found in reviewing conclusions across a number of studies — "meta-analyses" — for a June 2019 article in the Perspectives on Psychological Science journal.

"All of the meta-analyses do in fact point to the conclusion that, in the vast majority of settings, violent video games do increase aggressive behavior but that these effects are almost always quite small," they concluded.

A competing view

One study posed something of an exception to the other research.

"Exposure to violent video games increases children’s dangerous behavior around real firearms," concluded a study published in May 2019 by two Ohio State University researchers.

The researchers tested in a laboratory setting pairs of children, ages 8 to 12, who knew each other; 242 children in all were tested. Pairs of children played or watched one of three versions of the game Minecraft for 20 minutes — one violent with guns, one violent with swords, one nonviolent. The pairs of children were then placed in a different room and were told they could play with toys and games for 20 minutes. A cabinet in the room contained two hidden disabled handguns with counters for trigger pulls. A larger number — 220 of the 242 children — found the gun. Children exposed to a violent game, especially the one with guns, were more likely to touch a handgun, held a handgun longer and pulled the trigger more times, including at themselves and their partner.

"Exposure to violent media is one possible risk factor for violent behavior, but there are many," the lead author of the study, communication professor Brad Bushman, said in an interview. "Some obvious risk factors are easy access to guns and hateful white nationalistic rhetoric."