The PTC study reviewed programming shown during three weeks from the summer of 2005. It examined shows on four broadcast and four cable networks: ABC, Fox, NBC, WB, ABC Family, Cartoon Network, Disney Channel and Nickelodeon.
The group's 2002 study of prime-time TV reviewed six broadcast networks.
The study found the Cartoon Network had the most violence overall, while the Disney Channel had the least.
It singled out the "Teen Titans" superhero cartoon, shown on the Cartoon Network and the WB, as the most violent show for children.
Naturally, not everyone is buying this.
"This group has a history of making sensational claims in order to push government control of content," said Jim Dyke, executive director of TV Watch.