MONDAY, April 3 (HealthDay News) — Watching too much violent TV and playing too many violent video games takes a toll on children’s social and physical development, researchers report.

“We found that the more TV they watch, the less time they spend with their friends,” said researcher David S. Bickham, a research scientist at the Center on Media and Child Health at the Harvard School of Public Health. However, “this relationship really only holds true for violent TV,” he added.

Another study found that violent video games appear to instill poor attitudes in children when it comes to their own health, while promoting risky behaviors. A third report found that mature-rated video games often include explicit sexual imagery and language content not included on warning labels.

These and other studies devoted to the media’s effects on children appear in April’s special themed issue of the journal Archives of Pediatrics & Adolescent Medicine.

In the first report, Bickham and a colleague collected data on 1,356 children ages 6 to 8 and examined how watching violent TV affected social integration.

They found increasing amounts of social isolation among children with higher levels of exposure to violent TV programming. To explain this finding, Bickham speculated that, since violent TV is linked with aggressive behavior in children, it makes it harder for these children to get along with other children. “Kids are watching violent TV, they are becoming more aggressive, and that aggression is making it more difficult for them to interact with their peers,” he said.

In the second report, Sonya S. Brady, a postdoctorate fellow in psychiatry at the University of California, San Francisco, and a colleague tested the reaction of 100 college men, 18 to 21 years old, to two video games,Grand Theft Auto III or The Simpsons: Hit and Run.

“When the men played the more violent video game, Grand Theft Auto, versus the less violent video game, The Simpsons: Hit and Run, they had greater increases in blood pressure, and those who played Grand Theft Auto had more negative emotions and hostile feelings,” Brady said.

In seo services addition, those who played Grand Theft Auto had more permissive attitudes about alcohol and marijuana use, Brady said. “Video games cannot only influence aggression, but might also influence attitudes toward risk-taking behavior,” she said.

Brady’s team also found that those who played the violent game were less likely to cooperate with others after playing the game. “Media violence may predispose young people and adolescents not only to greater health-risk behavior, but also toward tension and conflict in their social interaction with others,” she said.

In the third study, a team led by Kimberly Thompson, an associate professor of risk analysis and decision science at the Harvard School of Public Health, found that 81 percent of mature-rated video games have violent or sexual content not noted on the label.

In its study, Thompson’s team played 25 percent of the mature-rated video games available.

“We found that the games contained depictions of substances or sexual themes or profanity that was not noted,” Thompson said. These findings mirror findings the same team has noted in other video games rated for younger children, she said.

The companies Entertainment Software Rating Board, which rates these games, doesn’t actually play them, Thompson noted. Instead, it bases its rating only on material provided by the manufacturer, she said.

“Parents really need to pay attention to the actual experience of the game and to what their kids are seeing, because the content descriptors are not necessarily providing full information about what’s in the games,” Thompson said.

Other re