Every parent needs a break from time to time—a few minutes to prepare dinner, do the laundry or quickly check e-mail. That's when the television suddenly becomes the best invention ever—an instant free babysitter that enthralls even the youngest infants and might, fingers crossed, even teach them a thing or two. But a new policy statement published today by the American Academy of Pediatrics suggests that not only do children under age two probably learn nothing from the television, but that watching too much can actually delay language development and cause attentional problems.

To be fair, it is impossible to keep kids from the TV entirely. "Screens are everywhere," remarks lead author Ari Brown, a pediatrician based in Austin, Texas. And studies have shown that some educational television programs, such as Dora the Explorer and Blue’s Clues , can improve vocabulary in older kids. "But that doesn't play out for this age group," Brown says.

Two studies have shown, for instance, that seemingly educational shows like such as Sesame Street actually have negative effects on language development when kids under two watch them. Two other studies suggest that occasional exposure does not help, but it also does not harm toddlers, either. Ultimately, when it comes to how a little bit of TV—under an hour a day, say—might affect kids under two, "we really just don't know," says Marie Evans Schmidt, a psychologist at the Center on Media and Child Health at Children's Hospital Boston. But it seems to provide no real benefits.

On the other hand, heavy television viewing is strongly associated with developmental deficits—a problem considering that 39 percent of families with infants have a television on constantly when they are awake and at home. A study published in 2008 by researchers in Thailand, for instance, compared prior television use in 110 normal toddlers with that of 56 language-delayed kids and found that those who had started watching TV under age one, and who watched more than two hours per day, were six times as likely as other kids to have language problems. In another study published in the journal Pediatrics in 2004 , researchers from the University of Washington in Seattle (U.W.) reported that, in testing kids age one and three, the more television they watched, the more likely they were to have attentional problems when they were seven.

Brown admits that it is impossible to be sure that TV itself is causing these problems—heavy television viewing may simply be an indicator of bad parenting in general. "Correlation does not mean causation, so we can't say that television use and of itself makes the child have delayed language skills," she says. "There is an assumption here that if the TV were off, then time would be better spent because the parent would be engaging with the child." And in some cases, Brown admits, that might not be the case.

But one thing is not up for debate: it is far better to let children engage in unstructured play than it is to plop them in front of the TV. When U.W. researchers gave toddlers a set of toy blocks to take home and play with for six months, the kids' language skills improved compared with a group that was not given blocks.

And these types of activities are things that kids can do on their own, when parents need a few minutes to themselves, Schmidt says. "Let them get a little bored," she says. "That's how they learn to entertain themselves and make discoveries, and that's when they can think freely."