For as long as 24 hours after playing video games, the after-effects of violence and aggression still linger.
Researchers from Ohio State and Central Michigan Universities assigned volunteers to play either violent games like Mortal Kombat or non-violent titles like Guitar Hero for 20 minutes.
Half of the players, who played violent games, were then asked to think about their gameplay and to identify ways by which they could improve when they play again over the next 24 hours.
The following day, lead study authors Brad Bushman and Bryan Gibson tested participants' aggression.
The male subjects who played violent games, but were not asked to think about them did not show any more aggression than normal, but those who had been asked to think about their violent gameplay were more aggressive than all of the other groups of players.
Women who played violent games and were asked to think about them did not show any increase in aggression 24 hours later.
"It was reasonable to assume that our lab results will generalise to the 'real world'," News.com.au quoted Prof Bushman and Prof Gibson as saying.
"Violent gamers usually play longer than 20 minutes, and probably ruminate about their gameplay in a habitual manner," they stated.
The study was published in the journal Social Psychological and Personality Science.