Abstract: The general aggression model (GAM, Anderson & Bushman, 2002) provides a framework of the negative effect of the violent video games. It is assumed in the GAM that individual acts of aggression are caused by the interactions between situational (e.g., frustrations, or the presence of firearms), individual (e.g., personality and attitudes), and biological (e.g., increases in blood pressure) variables. The previous studies have shown that violent video games play an important role in the increases of aggressive behaviors, aggressive cognition, hostility, psychological arousal, and physiological responses. Because most of the existent research focuses only on examining the relationship between aggression and the playing of the violent video games, it still remains unclear how the situational, individual, and biological variables interact with each other to lead to the aggressive behaviors.
The present two experiments were designed to investigate how the situational factors such as different ways (playing vs. observing) of presence of violence and different elements (shooting and blood) of violence in video games influence the aggressive behaviors and cognition. Seventy-two male undergraduates participated in the research. Half of the participants were asked to play the 45 degree shooting game called Alien Shooter, and the other half were asked to watch a video tape of somebody playing the same game. After a period of time of playing or observing the game, all the participants performed both the competitive reaction time task and the extrinsic affective Simon task.
The results showed that: (1) players were more aggressive than observers in both tasks, which means that active involvement in the violent video games yielded more negative outcome than passive involvement did, and (2) both shooting and blood elements promote aggression of players, but only the blood element (not the shooting element which attracted more attention of the observer) made observers to infer that other players would be aggressive. The findings of the present research are valuable in the video game design, at least in terms of decreasing violence in the games. According to the present results, the application of substitution of shooting and blood in the game will lead to less violence of the game, and it in turn will decrease the negative effect of video game play.

Key words: violent game, violent content, aggressive behavior, aggressive cognition, player and observer