Teaching parents to switch channels from violent shows to educational TV can improve preschoolers' behavior, even without getting them to watch less.

A new study's results were modest and faded over time, but may hold promise for finding ways to help young children avoid aggressive, violent behavior.

"It's not just about turning off the television. It's about changing the channel. What children watch is as important as how much they watch," said lead author Dr. Dimitri Christakis, a pediatrician and researcher at Seattle Children's Research Institute.

The study involved 565 Seattle parents, who periodically filled out TV-watching diaries and questionnaires measuring their child's behavior.

Half were coached for six months on getting their 3-to-5-year-old kids to watch shows like "Sesame Street" and "Dora the Explorer" rather than more violent programs like "Power Rangers." The results were compared with kids whose parents who got advice on healthy eating instead.

At six months, children in both groups showed improved behavior, but there was a little bit more improvement in the group that was coached on their TV watching.

By one year, there was no meaningful difference between the two groups overall. Low-income boys appeared to get the most short-term benefit.

"That's important because they are at the greatest risk, both for being perpetrators of aggression in real life, but also being victims of aggression," Christakis said.

The research was to be published online Monday by the journal Pediatrics.

--ASSOCIATED PRESS