Just because a toy's packaging says it's educational doesn't make it so. That's the finding from a new study in JAMA Pediatricsthat found some toys being marketed as language promoters got in the way of learning.

Research shows that for kids to understand, speak and eventually read or write a language, they need to hear it — lots of it. And it's never too early for parents and caregivers to get talking. That explains the booming industry in talking electronic toys that claim to help kids learn language.

The study focused on roughly two-dozen children between the ages of 10 and 16 months old. Researchers outfitted them with little microphones tucked into special vests or shirts that could record the infants playing at home with Mom or Dad.

Professor Anna Sosa, of Northern Arizona University, led the study and says she gave families three different kinds of toys to play with: books, traditional toys like stacking blocks and a shape sorter, and electronic toys.

"We had a talking farm — animal names and things," Sosa says of the electronic toys. "We had a baby cellphone. And we had a baby laptop. So you actually open the cover and start pushing buttons, and it tells you things."

Things like this:

Sosa says she picked those toys "because they are advertised as language-promoters for babies in this age range."

The parent-child couples were asked to play separately with each type of toy over the course of three days.

To understand what researchers heard, it's important to know what they were listening for. As we said above, babies learn language by hearing it. And research shows that interaction — the give and take between baby and parent — is key because early learning is intensely social.

You can hear it in this tape of one mother enjoying a book with her baby:

Compare that to the cut above, from the session with the electronic toy. Sosa says the difference isn't in what you hear but what you don't hear: Mom or baby.

"When there's something else that's doing some talking, the parents seem to be sitting on the sidelines and letting the toy talk for them and respond for them," Sosa says.

That's bad because the best way a toy can promote language in infants and toddlers is by stimulating interaction between parent and child. There's simply no evidence that a young child can learn language directly from a toy. It isn't responsive enough. It isn't social.

As for the other toys, traditional blocks and puzzles stimulated more conversation than the electronic toys, and books outscored them all. But don't underestimate the humble block. While traditional toys fell short of books in interaction quantity, Sosa notes, they kept pace in terms of quality.

A few caveats: The research focused on a relatively small sample of families. Also, of the 26 parents included, almost all were women, white and college-educated. Still, the data are clear: Electronic toys fell short.

"Personally, I think it's quite problematic," Heather Kirkorian says of the potentially misleading claims by toymakers. She studies child development at the University of Wisconsin, Madison and thinks Sosa has put her finger on a troubling trend.

"Toys and apps are particularly notorious for this," Kirkorian says, "making all sorts of grand claims about motor development, cognitive development and social development without having the research to back it up."

Kirkorian says technology can help teach older kids, but baby talk is best when it's human to human.

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