From the University of Luxemburg press release via ScienceDaily:
Current research from the University of Luxembourg, found that when participants were asked to select gift products after they had played a violent video game, inexperienced players selected more hygienic products, such as shower gel, toothpaste and deodorant and felt higher moral distress from playing violent games.
“Out, damned spot”, from Shakespeare’s Macbeth, resonates with these recent findings which link cleanliness and morality in violent video games. Dr. André Melzer, along with Dr. Mario Gollwitzer, Philipps-University Marburg, examined 76 participants following 15 minutes of violent video game play. “The need to cleanse to keep moral purity intact, the Macbeth effect, is a psychological phenomenon in which a person attempts to purify oneself in order to cope with feelings of moral distress”, describes Melzer. “We find that the Macbeth effect can result from playing violent video games, especially when the game involves violence against humans”. Melzer also stresses that experienced gamers seem to use different strategies to cope with violence in games.