The Prisoner’s Dilemma is an ethical conundrum that’s been used for years by psychologists, economists, and philosophers to explore human behavior. The basic scenario is this: two criminals have been captured and placed in separate cells. Neither prisoner is allowed to talk to the other, and the interrogators don’t have enough evidence to prosecute either one. If prisoner A confesses and prisoner B doesn’t, then prisoner A is released and prisoner B gets punished. If both confess, then both will get a lighter sentence. If neither confesses, then both will be released. For each prisoner, confessing guarantees a lighter sentence and opens the possibility of release, but also damns the other prisoner to certain punishment. If both prisoners trust each other, neither should confess, so ultimately the scenario is a measure of trust.
Fighting together in a military unit has often been held up as an example of the ultimate in trust: the friendships formed in the course of military service can last a lifetime. But does cooperation in a violent context necessarily lead to more trust than in a nonviolent context? Brad Sheese and William Graziano designed an experiment to test this scenario using a modified version of video game Doom and a modified version of the Prisoner’s Dilemma. Forty-eight college students were recruited to play violent and nonviolent versions of the game in teams of two. Each team was told that the highest-scoring individual would be rewarded with a $100 prize. They played the game for 25 minutes, with the goal of completing as many mazes as possible. In the violent version, players also had to fight off monsters and other hostile attackers. After this session, both players on the team had the same score.
After the game session, the two participants were escorted to separate rooms and offered a modified version of the Prisoner’s Dilemma. Players were given three choices: cooperate, defect, or withdraw. Absent the “withdraw” option, it was the standard Prisoner’s Dilemma. If both players decided to cooperate, then their scores would be multiplied by 1.5. If both players decided to defect, then their scores would be cut in half. But if one player chose to cooperate and the other player chose to defect, then the defector’s score would be doubled, and the cooperator’s score would be cut in half. The key difference is the withdraw option — if either player withdrew, both scores would remain the same.
Players were first asked to predict how their partners would choose. These results were the same, regardless of condition: 21 out of the 24 players in each condition (violent or nonviolent) predicted their partners would choose to either cooperate or defect. As you can see from the chart, cooperating or defecting is only beneficial if you predict your partner will cooperate — thus, these players believed their partners would trust them.
Next, players were asked to make their own choice. One player in violent condition and four players in the nonviolent condition chose to withdraw, indicating they didn’t trust their partner (this difference was not significant). However, of the remaining players, only one player in the nonviolent condition chose to defect, while seven players in the violent condition defected. These players trusted their partners to cooperate, but still chose to defect in order to gain an extra advantage (and deprive their partners of half their points). This difference was significant.
Sheese and Graziano argue that playing violent games therefore encourages antisocial behavior: since players of violent games are more likely to betray their partners for personal gain, violent game play has antisocial effects. However, they do acknowledge some limitations of the study. The nonsignificant difference in withdrawal rates trends towards nonviolent gamers displaying less trust of their partners than violent gamers. With a larger sample, this difference might turn out to be significant (of course, it might not). Also, the vast majority of participants in the study were white males, so the effects on other population groups may be different.
I’d add some additional caveats: we’ve reported before on how different types of violent games affect aggressive behavior differently — the same may be true for social behavior. Though this modified version of Doom does increase some antisocial behavior, other violent games may not. Video games are complex phenomena, so one limited study on one game certainly should not be used to justify such dramatic action as government censorship. On the other hand, parents are advised to take a close look at the games their kids are playing to see what types of behaviors they reward. Games that encourage haphazard violence might not be the best choice, especially for young kids.
Sheese, B.E., & Graziano, W.G., (2005). Deciding to defect: The effects of video-game violence on cooperative behavior. Psychological Science, 95, 354-357.