Research conducted in the US state of Iowa has found that there is a relationship between the level of youth violence and the habit of playing certain video games. Psychologists Craig Anderson and Karen Dill interviewed 227 students and asked them what games they liked. Then, in an experimental game, students had to punish their rivals with a noisy sound. The aggressiveness shown in this game and the games they liked had to do. Young people playing in the games Doom, Wolfenstein 3D or Mortal Combat learn to respond violently to problems and tensions and gradually behave in the same way to everyday events, according to the results of the research. According to Anderson, violent video games have more influence than television or movies, since they are interactive and force the player to behave violently.