Does exposure to violent media desensitize kids to violence?
Yes, repeated exposure to media violence can be desensitizing. But whether kids will become aggressive, antisocial, or unfeeling depends on a lot of factors: the amount, type, and context of the violence; the child's individual temperament and makeup; and the child's environment.
What's troubling is that kids on a typical media diet are exposed to a lot -- estimates are in the tens of thousands -- of graphically violent images and ideas through movies, games, and even advertisements. As children grow up, their brains and bodies crave stimulation, which violent media certainly provides. The combination makes kids, especially those with other risk factors (for example, difficult home environments or emotional challenges), particularly vulnerable to the desensitizing effects of media violence.
The connection is strong enough that the American Academy of Pediatrics and other child advocates recommend that parents severely restrict kids' access to violent media. You can do this by choosing age-appropriate content, co-viewing material that has violence and discussing it, and providing plenty of media with pro-social messages to help ease the effects.