Dead bodies. Bloodied faces. Tears. Terror.

Those are just some of the things that children see when they view news coverage of violent events, such as the truck attack in Nice, France, on Thursday.

Screen violence -- which includes violence in video games, television shows and movies -- is associated with aggressive behavior, aggressive thoughts and angry feelings in children, according to a policy statement released by the American Academy of Pediatrics early Monday.

"Screen violence, particularly when it is real but even if it is virtual, is quite traumatic for children regardless of age," said Dr. Dimitri Christakis, director of the Center for Child Health, Behavior and Development at Seattle Children's Research Institute and lead author of the statement.

"It is not uncommon to see increases in nightmares, sleep disturbances and increased general anxiety in the wake of these events. While it is true that the horrific events of this past week can happen at any time, the real risk to individuals remains low," he said. "Children need [that] reassurance."

For the statement, which was published in the journal Pediatrics, Christakis and colleagues reviewed and summarized more than a dozen studies and meta-analyses about the effects of virtual violence and aggression on children's attitudes and behaviors. They defined virtual violence as forms of violence experienced or witnessed virtually on a screen.

After the review, the statement authors made specific recommendations for doctors, parents, the media industry and policy makers to better prohibit easy access to violent media for young children.

"Parents should be mindful of their children's media diet and reduce virtual violence especially if their child shows any aggressive tendencies," Christakis said.

During a time of much conflict in the news, Christakis advises parents to reassure their children that there are still mostly good people in the world. He recommends that parents show children stories of people helping each other, and not hurting each other.

"We have done research showing that such events frighten children," said Brad Bushman, professor of communication and psychology at Ohio State University, who was not involved in the new statement.

The statement authors also called for the federal government to oversee the development of its own media rating system, rather than relying on the entertainment industry's rating of violent content in video games, movies and television.

"We know from hundreds of studies on thousands of children that there is a link between 'virtual violence' and real-world aggression," Christakis said. "On average, the effect is in what we would deem the small to moderate range, but equivalent to the link between passive smoke exposure and lung cancer -- something that municipalities have reacted to by enacting non-smoking ordinances."

Christakis is quick to point out that there are benefits when children consume nonviolent media. For instance, he led a 2013 study that found that prosocial and educational screen time -- including television and video games -- can significantly enhance social and emotional competence in children.

What do other scientists think of the new statement? Dr. Douglas Gentile, a professor of psychology at Iowa State University who has studied screen time and children, said the new statement suggests that often it's not the quantity of media but the quality that can influence aggression in children.

"Often, there are people who like to take extreme positions. Either the studies show games are creating a generation of shooters, which the science does not support, or they say there is no evidence that there are harmful effects, which the science also doesn't support," Gentile said.

"It is important to have our public health organizations do these types of reviews so the public can cut through all of that opinion out there," he said. "Everyone has an opinion, but not all opinions are supported by the science."

Source: CNN