In the wake of last week’s shooting at Marjory Stoneman Douglas High School in Parkland, Fla., critics again pointed to violent video games as an instigator of real-life violence.

President Trump on Thursday joined the chorus, warning about children's exposure to violence in video games, movies and on the Internet. "We have to do something about maybe what they're seeing and how they're seeing it. ... We may have to talk about that also," he said in a meeting with state lawmakers on school security.

A neighbor of accused shooter Nikolas Cruz told the Miami Herald that Cruz “escaped his misery” by playing video games for as much as 15 hours a day. “It was kill, kill, kill, blow up something, and kill some more, all day,” he said.

Gary Abernathy, a Washington Post contributing columnist and publisher of the Hillsboro (Ohio) Times-Gazette, noted this week that modern action films, TV shows and video games "outdo themselves in depicting gun violence committed so casually and with such frequency that viewers become dangerously numb to it."

Kentucky Gov. Matt Bevin posted a video to his Facebook page last week, urging lawmakers and "anyone who's in a position of influence" to consider how to repair the nation’s cultural fabric, which he said is “getting shredded beyond recognition.” Speaking to a radio interviewer, Bevin blamed a "culture of death that is being celebrated" via violent video games, TV shows and music.

A few researchers have suggested that violent games are “exemplary teachers of aggression.”

Not so fast, says Villanova University psychologist and researcher Patrick Markey. “All we can really say for sure is that there does not appear to be a link at this time between violent video games and school shootings,” he said. “And if there is a link, it goes in the opposite direction.”

That is, school shooters are actually less likely to be interested in violent games than their peers. A few, such as Virginia Tech gunman Seung-Hui Cho, had no interest at all — a fact that surprised his roommate, who “thought it was weird he didn’t play video games,” Markey said.

In fact, only about 20% of school shooters play video games, compared with about 70% of high school students overall.

Markey, co-author of the 2017 book Moral Combat: Why the War on Violent Video Games Is Wrong, said school shooters as a group “tend to do things that aren’t typical of their peers.” Typical teenage behaviors include playing video games, many of them violent. “It’s just a sign of a healthy childhood to do things that our peers do, even if parents don’t like it,” he said.

Previous research supports his assertion, suggesting that when violent games and media are released, real-life violence actually drops. In 2011, University of Texas economist Michael R. Ward and two colleagues found that higher rates of violent game sales coincided with a drop in crime — especially violent crime.

The perceived games-and-violence connection is nearly as old as the first-person-shooter video game itself. After the Columbine attack in 1999, victims’ families sued more than two dozen gamemakers, saying games such as Doom, a first-person shooter that teen gunmen Eric Harris and Dylan Klebold played, desensitized them to violence.

A judge dismissed the lawsuits because the games weren’t subject to product liability laws — they hadn’t “failed” like a badly wired toaster. But the lawsuits and post-Columbine uproar in Congress added to a heated debate that had pushed the industry to adopt a ratings system similar to that of movies.

A year after Columbine, the U.S. Secret Service and U.S. Department of Education looked at the habits of 41 school shooters, including Harris and Klebold. They found that five of them were interested in violent games, but that twice as many liked violent movies and books. The largest group, more than one in three, exhibited an interest in a different kind of violent media: their own writings, such as poems, essays and journal entries.

Twelve years later, in the wake of the shooting at Sandy Hook Elementary School in Newtown, Conn., Wayne LaPierre, executive vice president of the National Rifle Association, criticized the video game business as a “callous, corrupt and corrupting shadow industry that sells and sows violence against its own people."

But when Connecticut State Police investigated in 2013, they found a surprising video game link: Adam Lanza, the 20-year-old gunman, had obsessively played the game Dance Dance Revolution, a Japanese arcade staple, for nearly a decade. Once he was old enough to drive, Lanza would spend all night in the lobby of a movie theater, challenging others to beat him.

A subsequent report from the state Office of the Child Advocate noted that Lanza had played the game as far back as 2003, often dancing to the point of physical exhaustion. Investigators said this could have been a way for Lanza “to contain anxiety-producing impulses and thoughts.” One witness said the theater manager on occasion had to unplug the game to get Lanza to leave.

Other research has shown that countries that spend the most per-capita on video games have lower gun-related murder rates than the USA. Our gun-related murder rate is about 20 times the average, and virtually every other nation — the ones that spend more on video games and those that spend less — have lower gun-related murder rates.

A few studies have shown that playing violent video games temporarily makes players more aggressive — in a study in 2009, playing Mortal Kombat: Deadly Alliance on a PlayStation prompted participants to offer spicier hot sauce to lab volunteers who said they didn’t like spicy foods. The aggressive tendencies wore off within moments, researchers found.

In other words, Markey said, playing a game such as Mortal Kombat might have a fleeting effect, but it “doesn’t alter us fundamentally.”

Actually, he said, policymakers need to stop debating these effects — in the face of years of research findings, such debates are problematic.

“I think we’re at a point now where it’s becoming dangerous,” Markey said. “The biggest danger we have is that we are using these types of studies — hot sauce and such — to distract from what could be real causes of violence. As a field, we know better at this point.”