Today, 65% of American adults and nearly all teenagers play video games. They look more real than ever and often show detailed violence. Since their early days, video games have come with an implicit assumption that they're probably doing something bad to us. More than three-quarters of parents believe media violence, including video games, is contributing to America's culture of violence.

The Independent Record | January 6, 1982

But what do we actually know about how violent games affect us? While psychologists have been studying this issue for decades, and most have concluded there's a connection between violence in games and aggression, the current research community includes a small but vocal group convinced otherwise. The stakes of the debate are high. The video game industry globally is expected to pull in $152.1 billion in 2019, with the market growing 9% a year to $196 billion by 2022, according to Newzoo. Research firm Pelham Smithers Associates shows that the market exploded from $25 billion in 1976 to $136 billion in 2018. Violence in games is not a new phenomenon. In 1976, game company Exity released a title called "Death Race." To play, you put your hands on an actual steering wheel, your foot on a pedal, and you drive around, murdering anything in your way. You hear the screams of your victims and their gravestones litter the screen.

Death Race (1976) CNBC | Adam Isaak

That was four years before the release of Pac-Man. Its graphics are primitive and barely recognizable. Nonetheless, the game resulted in what was perhaps the first widespread panic about violence in video games. The almost true-to-life quality of today's games has dramatically heightened those concerns. Violent games like "Call of Duty," "Counter-Strike" and "PlayerUnknown's Battlegrounds" (PUBG) are hugely successful. Epic Games, the publishers of Fortnite, made a reported $3 billion in profit in 2018. Psychologists and the broader public may be talking about the issue in very different ways, but the concern is widespread among politicians, parents and the media.

CNBC | Adam Isaak