The evidence has been conclusive that playing violent video games increases the player’s level of aggression. The term aggression is used by scientists specifically to mean “willingness to harm others”.
So if a violent video game player’s “willingness to harm others” increases, does that mean they’ll go out and commit a violent crime? No it doesn’t. It just means that whatever level of aggression a person already has, will be increased by playing violent video games. The more they play, the more their level of aggression is increased. So, someone who starts out very non-aggressive will (after playing violent video games) become less non-aggressive. And someone who starts out very aggressive will (after playing violent video games) become even more aggressive. So if someone is already so aggressive that they are teetering on the edge of committing a violent crime, it would make sense that hours of playing violent video games would push them over that edge, to the point of committing a violent crime. The result would be that most people who play lots of violent video games would not have their aggression level increased to the point of committing a violent crime, but that a minority of players would indeed have their level of aggressiveness increased to the point of committing a violent crime.
But is this what is actually happening? Has the enormous dedications of millions of players to violent video games actually lead to an increase in violent crime?