Grand Theft Auto IV hit the stores last week like a tsunami, and is expected to become one of the biggest sellers in video game history. Commentators agree that the game, with its sophisticated graphics, sets a new standard for realistic violence and sex.

News reports and game-related websites give the flavor of what avid gamers are getting for their 60 bucks. GTA IV opens with an S&M sex scene. Players can gun down ordinary citizens, beat up prostitutes, murder cops and enjoy lap dances from strippers. This mayhem is accompanied by what the Associated Press called a "nearly constant stream of filthy language."

"[T]eenage boys of America," wrote one reviewer, "... you can still kill and maim and plunder and screw until your heart is full," but now "the violence is no longer cartoonish." Thanks to GTA IV's new realism, when G-stringed strippers grind the main character's lap, the player's controller vibrates in response.

The launch of a game like GTA IV -- labeled "M" for sale only to buyers 17 and over -- always seems to provoke the same debate. Critics charge that the game harms children, who can easily get their hands on it.

Research confirms that violent media increase young people's aggressive thoughts and behavior and decrease their self-control and the inclination to help others. Adolescents who play violent video games tend to be more hostile, to argue more with teachers, to get into more physical fights, and to do more poorly in school, one national study reports.

Video game representatives make two arguments when faced with such data. First, they insist that parents are the gatekeepers for their children's play.

Sounds good, but ask any 15-year-old male if it's really true.

Second, industry spokespeople downplay the youth problem's relevance, pointing to surveys that suggest that the average gamer is somewhere between the ages of 29 to 32.

This is comforting?

Let's assume that's true. Is it supposed to be comforting that millions of grown men get their "entertainment" from pretending to blow away cops and hook up with prostitutes?

Anyone who has raised a child, or worked for a boss -- or looked honestly at his or her own shortcomings -- knows that we human beings have both good and bad instincts and impulses. We have the potential to be kind, generous and self-controlled, but we also can be selfish, power-hungry, violent and cruel.

History amply illustrates humanity's dark side. In ancient Rome, crowds of thousands of people -- not too different from us -- cheered with frenzied blood lust as animals and human beings were torn to pieces. In the 15th century, public executions took on a festival atmosphere as victims were disembowled or burned at the stake.

Not just a few bad apples

Our own age has witnessed the horrors of genocide in Nazi Germany and Rwanda. These atrocities were not perpetrated by a handful of human monsters, but by thousands of ordinary people.

Contemporary Americans are not immune from sadistic impulses. The renegade U.S. soldiers who humiliated and maltreated prisoners at Abu Ghraib were reportedly imitating the pornified culture from which they came.

Games like GTA IV stimulate and glamorize our dark impulses. They create a taste for the psychological thrill that can come from dominating and degrading others. They encourage us to strip our fellow human beings of their dignity, and view them merely as objects of violence or sexual desire.

The hazards of violent games will only increase as new, more advanced technologies like the Wii system take hold. With Wii, for instance, you can go beyond punching buttons or manipulating a joystick -- you can act out a game physically. As more games gain the technology that lets players go through the motions of stabbing opponents, pummeling prostitutes and simulating sex, they are likely to exert an even stronger psychological hold on thrill-seekers.

We all have a dark side

Am I suggesting that those who spend hours playing violent video games are on the way to becoming real-life killers, torturers or rapists? Of course not. But all of us have a potential for coarseness and cruelty that may emerge after months or years of immersion in lurid and prurient games.

The average 32-year-old man who plays violent video games -- and spends his free hours fantasizing about murdering passersby and roughing up strippers -- is likely to be someone's husband and father. What qualities of character will his wife find when she looks to him for love, steadiness and fidelity?

And when his young son looks to Dad as a role model -- well, that's the problem, isn't it?

Katherine Kersten