President Donald Trump said the video game industry is partially to blame for the El Paso massacre, claiming that games glorify violence.

Some gaming company stocks lost as much as 6% of their value on Monday before stabilizing on Tuesday.

However, there's no research that links gun violence to video games, video game company and some independent research suggest.

In the aftermath of Saturday's mass shooting in El Paso, President Donald Trump placed blame on video game makers, seeking to link games like "Call of Duty" with a rise in gun violence. Fears of a backlash against the industry sent shares of game developers tumbling on Monday

While gaming companies recovered some that lost ground on Tuesday, with "Call of Duty" maker Activision Blizzard rising in early afternoon trading after losing 6% of its value on Monday, the questions facing the industry may not disappear as quickly. Other video game makers saw their stocks slide Monday, including Take-Two Interactive, the maker of "Grand Theft Auto," and Electronic Arts.

Video game companies have long drawn criticism across the political spectrum for what some say is their capacity to incite violence in some players. Critics are also pointing to the suspected El Paso shooter's reported mention of "Call of Duty" in his manifesto. According to critics, such games normalize violence and are a factor in the rise in mass shootings.

"We must stop the glorification of violence in our society," Mr. Trump said Monday in remarks at the White House after the El Paso massacre. "This includes the gruesome and grisly video games that are now commonplace."

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Other lawmakers chimed in, with both House Minority Leader Kevin McCarthy and Texas Lt. Gov. Dan Patrick telling Fox & Friends that they believe there's a link between violent games and real-world violence. "We've watched from studies, shown before, what it does to individuals, and you look at these photos of how it took place, you can see the actions within video games and others," Patrick said.

"No causal connection"

Despite such claims, there's a lack of research backing up those assertions, according to the video game industry.

"Numerous scientific studies have established that there is no causal connection between video games and violence," the Entertainment Software Association said in a statement to CBS MoneyWatch. "More than 165 million Americans enjoy video games, and billions of people play video games worldwide."

Both the industry and its supporters also point to another fact: Violent games like "Call of Duty" are played across the globe, yet no other country has a rate of gun violence as high as the U.S., suggesting that causes other than video games may be to blame.

"There are no longitudinal studies that show a link between violence and video games," Benjamin Burroughs, a professor of emerging media at the University of Nevada, Las Vegas, told the Associated Press. "Certainly, there is no linkage to gun violence."

Video game catharsis?

One 2014 study from researchers at Villanova and Rutgers universities not only found no link between video games and real-world violence, but also that crimes like aggravated assaults tended to decrease after a video game release -- possibly because it allows for a "catharsis" through expressing aggression in a game rather than real life.

Claims that video games are linked to "the murderous rampages of male adolescents" is a false correlation, the authors noted. About 9 of 10 young men play video games, which means claiming a perpetrator was incited by a video game "is as pointless as pointing out that the criminal also wore socks," they wrote.

Psychologist Jill Peterson and sociologist James Densley, who have compiled a database of mass shootings going back to 1966, say a range of other factors can lead people to commit violence.

"These are complicated pathways," Peterson told CBS This Morning. "It's childhood trauma and mental health and bullying and other stress factors. Picking out any one piece doesn't work."