How do violent movies and video games affect children?

Since the first motion picture, adults have worried about how children would respond to violent imagery. Now that mobile screens offer kids unlimited access to violent images and videos, we have even more to worry about.

Virtual violence is any act of aggression your child might absorb through TV, movies, video games, social media and other digital channels. It includes the simulated violence in blockbuster films and amateur videos and the animated violence in cartoons and interactive games. News reports of real-life tragedies also deliver an endless loop of virtual violence.

Virtual violence needn't involve physical harm. Aggressive, threatening, racist or hateful statements can be just as damaging to children who witness them than to those they are directed toward.

What children see (or play) influences how they behave

Decades of research link virtual violence to aggressive thoughts, feelings and actions in children. Even though we're still learning about the effects of violent content video games and social media, experts agree that kids are deeply influenced by brutality wherever they experience it.

Witnessing violent acts - whether real or simulated - may give kids the sense that aggression is normal and acceptable. This may lead them to act out what they see and hear, especially if they witness violence at home or in their communities. Newer studies show exposure to virtual violence can trigger mental health struggles, including depression and anxiety.

Five practical steps to protect children and teens

You can't shield your child from all forms of virtual violence. But these five steps can help minimize the harm that violent content can do to your child's health.

1.) Limit what very young children watch and play. If you have children under age 6, try to exclude violent content. Young children cannot distinguish fantasy from reality. To them, even violence that seems cartoonish to us seems real.

2.) Use parental controls and media ratings. A variety of technologies promise to offer you control over your children's viewing and playing habits, and they can certainly be helpful if you learn how to use them. But no program can replace your involvement in your children's choices. Young children should always ask permission before they watch or play video games on any device. Learn more about TV content ratings (www.tvguidelines.org/resources/TV_Parental_guidelines_Brochure.pdf) and movie ratings (www.filmratings.com/Tips) that can help you choose wisely for your family. The Entertainment Software Rating Board (esrb.org) publishes helpful ratings for games and apps, and Common Sense Media (commonsensemedia.org) provides a wealth of ratings, tips and insights.

3.) Watch or play with your kids. Your attention has tremendous power. Explain that you're interested in the things they like to watch and play. Sit down with them and gauge the level of virtual violence in their favorite shows, movies, games or apps. You'll almost certainly be surprised at what you learn!

4.) When enjoying entertainment with your child, take time to talk with them about it. Ask how especially violent scenes made them feel. Show interest in their opinions without arguing with them. You can share your own views without suggesting that any single opinion is 100% right or wrong. For example, you might say, "I can understand why that character was angry. But I hate to see people get violent instead of finding other ways to settle their differences." These conversations can compare what your child is seeing with your family values such as respect, tolerance, kindness and mutual understanding.

5.) Create a family media plan. The American Academy of Pediatrics offers an easy-to-use tool (healthychildren.org/english/fmp/pages/mediaplan.aspx) to help parents and caregivers manage family media usage. You'll find a list of media priorities to choose from, practical tips, and the ability to print and share your plan with caregivers, family and friends. You can even save your plan and edit it as your family's needs change over time.

No single violent movie or video game will make your child violent. What matters is the amount and intensity of virtual violence your child absorbs over time. You can protect your child's health by monitoring what they watch and play and putting common-sense rules in place, based on your child's age, temperament and unique needs.

• Children's health is a continuing series. This week's column was provided by the American Academy of Pediatrics. For more information, visit healthychildren.org.