Survey: Are smartphones, iPods and tablets suitable for children?

(NBC) - Ipods, tablets and e-readers are popular gifts this holiday season for kids and adults.

As the interactive app market for children grows, so does the concern that exposure to yet another screen may impact their development.

A new survey from the nonprofit group Common Sense Media finds nearly half of 2 to 4 year olds, and ten percent of children younger than that, have used a smart phone, tablet or video iPod.

The American Academy of Pediatrics just released new guidelines that say children under two should have little to no "screen time" after studies showed youngsters who watch too much TV may have developmental delays, but in a world where TV is just one of many digital distractions how do interactive tablets fit in to the screen time rule?

Experts say science has not caught up with technology.

"There are some possibilities for educational tools learned on these screens and that's pretty cool - but we just don't know the benefits or risks yet because no one has had time to study this group of kids," said Dr. Ari Brown, pediatrician.

Brown is the lead author of the new screen time recommendations.

She says tablets are different from TV because kids can interact with them, which could inspire new ways to learn.

Still, she stresses they don't take the place of unplugged play time.

"What's really important for young children is they learn from real humans and real objects and nothing in technology is going to be able to approximate the real thing," she said.

Doctors say children are likely to imitate their parent's behavior, so mom and dad may need to put down their iPad, smartphone, or computer if they expect their kids to do the same.

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