Degree Type


Date of Award


Degree Name

Master of Science




This experiment examined the effects of rewarding and punishing violent actions in video games on aggressive behavior towards a provoker and an innocent bystander. First, every participant completed an essay on a controversial topic. Next, each participant was randomly assigned to play one of the four versions of a racecar video game for twenty minutes. The four versions were: 1) killing bystanders and race opponents was rewarded, 2) killing bystanders was punished and killing race opponents was rewarded, 3) all violent action was punished, and 4) nonviolent. Next, all participants received severe negative feedback on their essay (provocation) by another participant. After receiving the negative feedback, each participant was given the opportunity to aggress against either the person responsible for the provocation (aggression against provoker) or another participant who was not responsible for the negative feedback (displaced aggression), by issuing bursts of static into the participant's headphones. A significant linear contrast demonstrated that participants displayed more direct aggression when they played a video game that rewarded for violent actions. The number of pedestrians killed in the violent game versions mediated direct aggression in the laboratory. Trait aggressiveness was also positively correlated to laboratory aggression. Past violent video game exposure was positively correlated with trait aggressiveness, even after controlling for total video game exposure. The effect of video game violence on displaced aggression was unclear. This experiment demonstrates that reward and punishment for violent actions within video games can affect a player's aggressive behavior towards individuals after game play has ceased. Results of this experiment are discussed in terms of the General Aggression Model.



Digital Repository @ Iowa State University,

Copyright Owner

Nicholas Lee Carnagey



File Format


File Size

83 pages