1. Craig Anderson, Department of Psychology
Violent Video Games
Craig Anderson, Department of Psychology
Iowa State University

2. A Meta-Analytic Review of the Scientific Literature
In total, the research on exposure to video and television violence suggests that playing violent video games will increase aggressive behavior in children and young adults.
This finding is supported by experimental and field studies among both males and females.
Research indicates also that exposure to video violence increases psychological arousal and aggression-related thoughts and feelings.

3. A Meta-Analytic Review of the Scientific Literature
Exposure to violent games increases physiological arousal toward aggression.
Exposure to violent games increases aggressive actions.
Exposure to violent games decreases positive prosocial (i.e., helping) actions.

4. A Meta-Analytic Review of the Scientific Literature

5. Definitions
Violent Media: Depiction of intentional attempts by individuals to inflict harm on others. An “individual” can be a non-human character (i.e., cartoon) or a real person.
Aggression: Behavior intended to harm an individual who is motivated to avoid that harm. It is not an emotion or aggressive thought, plan, or wish.

6. Definitions
Violence: Extreme forms of aggression, such as physical assault or murder. All violence is aggression, but not all aggression is violence.
The key point is that this research concerns itself with behavioral outcomes of viewing extreme violence, not with thoughts or emotions related to viewing aggressive behavior with unintentional harm to others.

7. Video Game Statistics
On average, youths between the ages of spend 40 hours per week using some type of media, not counting school or homework assignments.
Television is viewed most often, but the popularity of other video media is rising.
Approximately 10% of youths ages 2-18 play console and computer video games more than 1 hour per day.

8. Video Game Statistics
Approximately 15% of men entering college played at least 6 hours per week of video games as high school seniors (1999).
Violent video games increased in popularity during the 1990’s. In games such as Mortal Kombat, Street Fighter, and Wolfenstein 3D, the object is to maim, wound, or kill opponents. The violence is graphic visually and in its sound effects.

9. Research Statistics
Five decades of research into the effects of exposure to violent television and movies have produced a thoroughly documented and highly sophisticated set of research findings.
Even brief exposure to violent TV or movie scenes causes significant increases in aggression and that repeated exposure of children to media violence increases their aggressiveness as young adults.

10. Theoretical Rationale
According to the General Aggression Model, long term effects of exposure to violent media result primarily from the development, rehearsal, and eventual automatization of aggressive knowledge structures.
That is, viewing aggression, and in particular, practicing aggression through interactive video games, increases aggressiveness as a formed habit. “You play the game like you practice.”

11. Theoretical Rationale
Children are more likely to imitate the actions of a character with whom they identify.
In violent video games the player is often required to take the point of view of the shooter or perpetrator.
Video games by their very nature require active participation rather than passive observation.

12. Theoretical Rationale
Repetition increases learning. Video games involve a great deal of repetition. If the games are violent, then the effect is a behavioral rehearsal for violent activity.
Rewards increase learning, and video games are based on a reward system.

13. General Aggression Model

14. General Aggression Model

15. Myths and Facts
Myth 1. Violent video game research has yielded very mixed results.
Facts: Some studies have yielded nonsignificant video game effects, just as some smoking studies failed to find a significant link to lung cancer. But when one combines all relevant empirical studies using meta-analytic techniques, the effects emerge with considerable consistency.

16. Myths and Facts
Myth 2. The studies that find significant effects are the weakest methodologically.
Facts: Methodologically stronger studies have yielded the largest effects. Thus, earlier effect size estimates —based on all video game studies— probably underestimate the actual effect sizes.

17. Myths and Facts
Myth 3. Laboratory experiments are irrelevant (trivial measures, demand characteristics, lack external validity).
Facts: Arguments against laboratory experiments in behavioral sciences have been successfully debunked many times by numerous researchers over the years.

18. Myths and Facts
Myth 3 Facts (Continued): Specific examinations of such issues in the aggression domain have consistently found evidence of high external validity. For example, variables known to influence real world aggression and violence have the same effects on laboratory measures of aggression.

19. Myths and Facts
Myth 4. Field experiments are irrelevant because aggression measures are based either on direct imitation of video game behaviors or are normal play behaviors.
Facts: Some field experiments have used behaviors such as biting, pinching, hitting, pushing, and pulling hair, behaviors that were not modeled in the game.

20. Myths and Facts
Myth 4 Facts (Continued). The fact that these aggressive behaviors occur in natural environments does not make them "normal" play behavior, but it does increase the face validity (and some would argue the external validity) of the measures.

21. Myths and Facts
Myth 5. Correlational studies are irrelevant
Facts: Correlational studies are routinely used in modern science to test theories that are inherently causal. Well conducted correlational studies provide opportunities for theory falsification. They allow examination of serious acts of aggression that would be unethical to study in experimental contexts. They allow for statistical controls of plausible alternative explanations.

22. Myths and Facts
Myth 6. There are no studies linking violent video game play to serious aggression.
Facts: High levels of violent video game exposure have been linked to delinquency, fighting at school and during free play periods, and violent criminal behavior (e.g., self-reported assault, robbery).

23. Myths and Facts
Myth 7. Violent video games affect only a small fraction of players.
Facts: Though there are good theoretical reasons to expect some populations to be more susceptible to violent video game effects than others, the research literature has not yet substantiated this.

24. Myths and Facts
Myth 7 Facts (Continued). There is not consistent evidence for the claim that younger children are more negatively affected than adolescents or young adults or that males are more affected than females. Even nonaggressive individuals are consistently affected by brief exposures. The literature has not identified a sizeable population that is totally immune to negative effects of media violence.

25. Myths and Facts
Myth 8. Unrealistic video game violence is completely safe for adolescents and older youths.
Facts: Cartoonish and fantasy violence is often perceived (incorrectly) by parents and public policy makers as safe even for children. However, experimental studies with college students have consistently found increased aggression after exposure to clearly unrealistic and fantasy violent video games.

26. Myths and Facts
Myth 9. The effects of violent video games are trivially small.
Facts: Meta-analyses reveal that violent video game effect sizes are larger than the effect of second hand tobacco smoke on lung cancer, the effect of lead exposure to I.Q. scores in children, and calcium intake on bone mass. Furthermore, the fact that so many youths are exposed to such high levels of video game violence further increases the societal costs of this risk factor.

27. Myths and Facts
Myth 10. Arousal, not violent content, accounts for video game induced increases in aggression.
Facts: Arousal cannot explain the results of most correlational studies because the measured aggression did not occur immediately after the violent video games were played. Several experimental studies have controlled potential arousal effects, and still yielded more aggression by those who played the violent game.

28. Myths and Facts
Myth 11. If violent video games cause increases in aggression, violent crime rates in the U.S. would be increasing instead of decreasing.
Facts: Three assumptions must all be true for this myth to be valid: (a) exposure to violent media (including video games) is increasing; (b) youth violent crime rates are decreasing; (c) video game violence is the only (or the primary) factor contributing to societal violence.

29. Myths and Facts
Myth 11 Facts (Continued). The first assumption is probably true. The second is not true, as reported by the 2001 Report of the Surgeon General on Youth Violence. The third is clearly untrue. Media violence is only one of many factors that contribute to societal violence and is certainly not the most important one. Media violence researchers have repeatedly noted this.

30. Need for Further Research
Several major gaps remain in the violent video game literature. One especially large gap is the lack of longitudinal studies testing the link between habitual violent video game exposure and later aggression, while controlling for earlier levels of aggression and other risk factors. Indeed, of the four major types of empirical studies mentioned earlier, this is the only type missing. There are such studies focusing on television violence but none on video games.

31. Need for Further Research
More research is needed to: (a) refine emerging general models of human aggression; (b) delineate the processes underlying short and long term media violence effects; (c) broaden these models to encompass aggression at the level of subcultures and nations.