[Glenn E. Meyer]

That is a great unknown at this time. Violence rates are dropping in general while intensive media is increasing.

That would argue that they don't have a very strong effect on society. The increase in gun crime in lower SES was happening during the drug wars - media was not a crucial component in that.

I think the best answer we have is that for people with existing psychological problems, the media (of all types) can channel their ideation and actions.

For folks without such, I think the effect is minimal for society with current media. Can intense cultural pressure desensitize folks - I think it can. But it would take the order of Nazi propaganda effects for a society. Densitization can also occur on the small group level with intense socialization (like the FSU band beatings).

But do the freely played games do it - I don't think we have the evidence for it.