Playing violent video s can have immediate and lasting effects on a person’s thoughts and behavior, new research shows. In fact, researchers report that the interactive and increasingly graphic mature of some video s makes them "potentially more erous" than violence-charged television and movies. Psychologists Anderson and Dill conducted two studies. In one study of 227 college students, the investigators found that students who more frequently played violent video s during junior high and high school were more likely to have engaged in " aggressive behavior". A second study in which 210 college students played either a violent or non-violent video revealed that the violence-packed increased subjects’ aggression immediately afterwards. In the first study, the investigators questioned students on their natural levels of aggression and irritability, and their delinquent(犯法的)behavior — for instance whether they had bit other students in the past year. The investigators found that students with aggressive personalities and those who more often played violent video s were more prone to real-life aggression. Students who considered themselves aggressive were also more likely to play violet video s. Since aggressive people may seek out violet s, coming to the conclusion that the video s caused real-life delinquency is too risky. However, the second study lined video- violence with immediate increases in aggression. Anderson and Dill had students play either a violent or a nonviolent and let the students believe they were playing against an opponent in another room after completing the video , participants played a competitive-reaction with their imaginary opponents, in this the winner was allowed to publish the loser with a noise blast(响亮的噪音). The researchers found that students who were fresh from the violent video blasted their opponents longer than those who played the nonviolent . Because video s show short-term and long-term effects, Anderson and Dill suppose that video violence influences behavior not by arousing aggressive feelings, but by teaching players to find "aggressive solutions" to problems. Unlike TV, many video s demand that player identify with the aggressor and actively participate in violence. In order to find out the short-term effect of violent video , researchers______.