Interestingly, you seem to imply that increase of aggression level is bad (conclusion of this study is that aggression is higher in teens that play violent game

Interestingly, you seem to imply that increase of aggression level is bad (conclusion of this study is that aggression is higher in teens that play violent games), while high level of aggression is most likely bad, it may very well to turn out that on average relative increase of aggression level in individual may have positive effects for said individual.