If video games contribute to mass shootings, why aren't almost all young people mass killers? 

An overwhelming number of American children between the ages of 2 and 17 are playing video games, according to a study by the NPD Group.

According to the research firm, 91% of kids (male and female) between 2 and 17, or about 64 million people (!), are playing video games, up 9 percentage points compared to 2009.

About 63% of the U.S. population plays video games, while about 70% of the world plays video games. When you consider the population of the world is nearly seven billion, the percentages represent many people.

That's a lot of people.

Yet many pro-gun advocates are quick to blame video games ... instead of guns themselves ... for the uptick in horrible mass violence the U.S. has seen over the last year. 

Enter Sen. Chuck Grassley (R-Iowa) on Wednesday, who, at a Senate Committee meeting on gun control, had harsh words for gun control supporters, blaming depictions of violence in the media and a broken mental health system for mass shootings.

Grassley urged the committee to support gun rights in any solution. Except for slavery, Grassley said that the Constitution limits only what the government could do, not what individuals can and can't do. He said that citizens were correct to suspect that "Congress may enact legislation that may lead to a tyrannical government."

Ah yes, the old government is a tyrant argument.

Additonally, Grassley accused violent video games of contributing to mass killings. Citing the manifesto of Anders Behring Breivik, a right-wing extremist who kiled 77 and wounded 242 people attending a Worker's Youth League meeting in Norway, Grassley said that video games could be used as mass killing training simulators. 

"Where is the artistic value of shooting innocent victims?" Grassley asked.

There is no clear scientific evidence to link violent video games with mass shootings.

There remains no justifiable reason for pro-gun advocates to blame video games for mass violence. This is only deflecting from more critical issues.