In the debate over media violence, a common view is that children are more affected by such material than are adults. Adults, the reasoning goes, have the right to enjoy whatever television programs, movies, music, or video games they choose—and are presumed responsible enough to view violence without becoming violent themselves. But children are thought to be much more impressionable. Those who hold this view believe parents have the right—and the responsibility—to limit their children’s exposure to media violence.

In fact, increased parental responsibility is one of the most commonly posed solutions to the problem of media violence. John Romano, producer of NBC’s program Third Watch, sums it up this way: “If you don’t want your kids watching, turn the darn thing [TV] off...