According to an article in ScienceNOW, videos like Baby Einstein and Brainy Baby, which are marketed to improve toddler language skills have exactly the opposite effect – children: [f]or every hour per day spent watching the videos, children understood an average of six to eight fewer words than did those of the same age who did not watch them–a 17-percentile drop in vocabulary.
It’s one thing if a product like this has no impact, but that it actually has the opposite of the intended effect…that’s mind boggling.
As for why the videos hurt vocabulary when they’re supposed to help it, Zimmerman can only speculate. One possibility, he says, is that the videos simply pacify children without teaching them anything. “It’s like empty calories for the mind,” Zimmerman says. Meanwhile, children not watching the videos are reading, interacting with their parents, or building with blocks.
A link to the abstract of the Zimmerman et al. article from the Journal of Pediatrics.