research has shown that video games can improve mental dexterity, while boosting hand-eye coordination, depth perception and pattern recognition. Gamers also have better attention spans and information-processing skills than the average Joe has. When nongamers agree to spend a week playing video games (in the name of science, of course), their visual-perception skills improve.
Then the bad:
[There's is] the popular theory that they are responsible for increasing real-world violence. A number of studies have reinforced this link. Young men who play a lot of violent video games have brains that are less responsive to graphic images, suggesting that these gamers have become desensitized to such depictions. Another study revealed that gamers had patterns of brain activity consistent with aggression while playing first-person shooter games.
This does not necessarily mean these players will actually be violent in real life. The connections are worth exploring, but so far the data do not support the idea that the rise of video games is responsible for increased youth violence.
As for gender differences:
Video games activate the brain’s reward circuits but do so much more in men than in women, according to a new study. … the men showed more activity in the limbic system, which is associated with reward processing. What is more, the men showed greater connectivity between the structures that make up the reward circuit, and the better this connection was in a particular player, the better he performed. There was no such correlation in women. Men are more than twice as likely as women are to say they feel addicted to video games.
Given the other benefits, one wonders if games could be made which women got more pleasure from, and what they’d be like. And of course we must forget another benefit for women we discussed before: 10 hours of video games virtually eliminates the difference between men and women in spatial acuity..