Television and video game violence can make children more likely to fight, smoke and have sex at an early age, according to recent studies. Because black children spend more time watching TV and playing with Xboxes, they are disproportionately affected, according to a Kaiser Family Foundation report.

Parents, remember: “You are still the most powerful influence on your kids,” says Dimitri Christakis, MD, coauthor of The Elephant in the Living Room: Make Television Work for Your Kids (Rodale; $24.95). Even if you’re not always home, “talk about the shows and violence they are viewing. Always make your values known.” He also offers the following tips:

• Use the V-Chip (available for sets 13 inches or larger) to block certain programs based on their ratings.
• Try to view content first, especially with video games, which are not always labeled properly for violence.
• No violence for kids under age 8, including news and cartoons.
• Keep the TV out of your child’s bedroom. Instead, put it in a common viewing area.