Canadian researchers, whose earlier work challenged assumptions about violent video games' links to aggression, have come out with a study that suggests when people from different social groups cooperate in a video game - even a violent one - their impressions of one another improve and prejudices diminish. While not quite ready to declare that violent video games are the path to global peace, the researchers say the findings could have realworld implications, such as in the development of military training.

"If allied American and British or Canadian forces are training together for an upcoming mission, co-operating in an online military training game before the mission may reduce inter-group bias and improve teamwork during the actual mission," the researchers wrote in the journal Psychology of Violence.

The study was led by Paul Adachi, a PhD student in psychology at Brock University. For the study, undergraduate students were invited to play a violent online game, Call of Duty: Black Ops. The game was set to a mode in which players work together to shoot and kill zombies.

Some students were told their playing partner was a fellow Brock student in an adjacent room, which was true. Other students were led to believe they were playing with a student at the University of Buffalo, across the border, which was false.

Before and after the games, students were asked to rate their attitudes about University of Buffalo students and Americans in general. These students in the latter group had "significantly more favourable" attitudes toward each.