Research Suggests That Sports And Racing Games Cause More Aggression In Players Than "Violent" Games Do
With yet another wrinkle in the often-contradictory, positively byzantine research in to the possible effect or effects that that may or may not be classifiable as aggression or violence which video games may or may not cause or be correlated to in relation to some but not all video games/video game genres, a line of research out of the UK is suggesting that sports and driving games are actually cause more of a reaction in test participants than ultra-violent games do.
According to a study being presented to the British Psychological Society's annual conference, players who were assigned to play football (aka. soccer) games scored higher in ratings of aggression after playing than did players who were assigned to play first-person shooters. This backs up earlier scholarship from the same researchers, Drs. Simon Goodson and Sarah Pearson, which demonstrated that racing games induce more neural excitation among gamers than shooters do.
What the researchers draw from this is that video games that simulate reality excite players' nervous systems more strongly than games less based in gamers' everyday lives (such as space marine epics). The studies measured heart rate, breathing rate, and brain activity via EEG, and found that players in the sports/racing groups had the highest levels of activity and excitation according to those measures.
All that being said, exactly how the researchers themselves draw a line between neurological and physiological excitation and "agitation and aggression" is not made clear in the articles referenced above. If I can find the original research (which wasn't readily available in online searches) I'll be back for an update.