Greg Toppo:

Pediatricians have long said children younger than 2 shouldn’t watch any television. But in new findings from a small-scale study, researchers say that even having a TV on in the background could be “an environmental hazard” for children.
For the study, released today, researchers observed 50 children, ages 1 to 3, for an hour at a time as they played alone in a small room with a variety of toys. Parents sat nearby, and for half of each session (starting either at the beginning or 30 minutes in), a small TV broadcast a taped episode of Jeopardy.
After videotaping and carefully analyzing the children’s reactions, researchers found that kids watched the TV only in snippets but that it modestly shortened their playtime. TV decreased play’s intensity and cut by half the amount of time children focused on a given toy.
The researchers chose Jeopardy on the theory that it would be “nearly incomprehensible” to toddlers.