Among 12- to 24-month old children who view educational baby videos, there does not appear to be evidence that overall general language learning improves or that words featured in the programming are learned, according to a report posted online that will appear in the May print issue of Archives of Pediatrics & Adolescent Medicine, one of the JAMA/Archives journals.

Children age 2 and younger spend an estimated two hours per day exposed to media on a screen, and the average age at which infants begin watching programming designed for their age group is five months, according to background information in the article. Manufacturers' claims that these infant-directed media can teach children specific vocabulary words have not been substantiated.

Rebekah A. Richert, Ph.D., and colleagues at the University of California, Riverside, studied vocabulary acquisition among 96 children age 12 to 24 months. Participants were tested on measures of vocabulary and general development, and their primary caregivers (77 mothers, seven fathers and four others) answered a series of questions about their children's development and previous exposure to educational media. Half of the children were then given an educational DVD to watch in their homes.

When additional tests were conducted after six weeks, there was no evidence children learned the words specifically highlighted in the DVDs, and watching the DVDs was unrelated to measures of general language learning. However, children whose parents reported that they began watching infant DVDs at an early age scored lower on a test of vocabulary knowledge.

The association between early DVD viewing and delays in language development could have several explanations, the authors note: "Parents who are concerned about their children's poor language abilities may use baby DVDs to try to teach their children, parents who use baby DVDs early may be less likely to engage in behaviors that promote language development or early viewing of baby DVDs may actually impair language development," they write.

"We conclude by encouraging researchers, parents, practitioners and programmers to consider the variety of cognitive factors related to whether very young viewers should be expected to learn from a DVD, regardless of DVD intent. Many cognitive factors play a role in learning from screens at this age, including children's developing perceptual systems, their understanding of symbols and analogy and their developing abilities to discriminate how much they should trust different sources of information," the authors continue. "Given that infant-directed media have become nearly ubiquitous aspects of many infants' lives, future research should continue to examine whether and how parents can use these DVDs effectively to teach their young children."

This research was funded by a grant from the National Science Foundation.