Aggressive

In the 'duh' category, we find this:

A study in the March issue of Psychological Bulletin, a journal of the American Psychological Association, shows that playing violent video games increases violent thinking, attitudes and behaviors among players. And it does nothing to promote positive social behaviors.

Psychologist Craig Anderson of Iowa State University and his team analyzed existing studies of 130,000 people from the U.S., Europe and Japan. His findings held for players in Western and Eastern cultures, for male and female players and for players of various ages.

In its review of data, the new research found that exposure to violent video games was associated with aggressive behavior, aggressive cognition and aggressive "affect." It desensitizes users and is associated with lack of empathy and a lack of "prosocial" behavior.