To more directly answer the question, Joseph Hilgard of Illinois State University and colleagues altered a single game to examine the unique influence of two aspects of game play: content and difficulty. The findings, published in Psychological Science, provide no evidence that either violent or difficult content intensifies players’ aggression toward others. For the study, Hilgard and colleagues created four versions of the video game Doom II. The more violent versions contained enemy graphics and sounds borrowed from Brutal Doom, a game mod designed to make everything more extreme — participants were tasked with defeating aliens, which resulted in the enemies exploding in gory fashion. The less violent versions contained sillier-looking alien enemies drawn from Chex Quest; rather than killing the aliens, participants were tasked with sending them home with their “zorcher.”
In the difficult versions of the game, the enemies fought back and participants had to restart the level if they received too many hits. In the easy versions, the enemies simply walked slowly instead of directly attacking the player.