Reuters Health is reporting that having the television on in the background while pre-schoolers play with their toys disrupts their efforts to sustain attention, even when they don’t pay much attention to it, and may harm their development. The research is published in the current issue of the journal Child Development.
My Take?
The American Academy of Pediatrics recommends no TV for children under age 2. Yet studies show that three quarters of very young children in America live in homes where the TV is on most of the time.
The researchers say, “Even though the effects of background television on play behavior found in this study are small, they may have a cumulative impact through large amounts of exposure at home. These may include poorer cognitive and language development and attention deficit symptoms.”
The bottom line is that the less TV your children are exposed to, the better. 
In my books God’s Design for the Highly Healthy Child and God’s Design for the Highly Healthy Teen, I have chapters chock full of tips on how to tame the TV in your home and how to become a TV-free home.