In 1977, video games became popular. Since then, companies have started introducing the technology into video games; they developed video games to make them more realistic and interactive, but many video games have become violent. They have bloody and horrific scenes where the player can be a part of the game and interact with games like Nintendo games. As a result, the children's behavior has worsened and they show violent behavior. For example, April 2002, Erfurt, Germany: A 19-year-old goes on a gun rampage in a school. His 20-minute shooting rampage leaves 17 dead, including himself. Psychologists have carried out studies to know whether these games are linked to violent games or not. Although there is some criticism, some experts believe that violent video games cause aggressive behavior, decrease pro-social and aggressive thoughts and feelings because they are realistic, interactive, and children can copy them. Violent video games increase aggressive behavior in children. Studies involving approximately 3,000 participants found that aggression has a direct relationship with playing violent video games. Certainly, this effect of violent video games on aggression is as strong as the effect of condom use on the risk of HIV infection; furthermore, they have found that violent video games increase aggression in both sexes in children and adults in experimental and nonexperimental studies (Anderson & Bushman 2001, pp. 353-359). Another study claims that violent video games lead children to commit crimes. Craig Anderson of Iowa State University at Ames and his colleague Karen Dill have found that people who play violent games are more likely to perpetrate assaults and robberies (Muir 2004, p.26A). Another study was published in the Journal of Adolescent by Barbara Krahe and her... half of the article... Anderson, PhD, shows that violent games could have even stronger effects on children's behavior because games are a violent behavior is extremely engaging, interactive, and rewarding, and children repeat this behavior over and over again as they play (Gentile Anderson, 2003, cited Violent Video Games Psychologists Help Protect Children from Harmful Effects 2004). Likewise, some types of violent video games can be as effective in training killers as flight simulators (B. Sullivan, cited in Wood & Johnson, 2000, cited Vessey & Lee 2001 p.608). Furthermore, a study conducted by Bandura and Walter found that children have an innate tendency to observe and copy the behavior of those significant in their lives, and are often successful in imitating a behavior correctly the first time (Bandura & Walter's cited in Vessey & Lee 2000, p. 608).