Led by Frederick Zimmerman and Dr. Dimitri Christakis, both at the University of Washington, the research team found that with every hour per day spent watching baby DVDs and videos, infants learned six to eight fewer new vocabulary words than babies who never watched the videos. These products had the strongest detrimental effect on babies 8 to 16 months old, the age at which language skills are starting to form. "The more videos they watched, the fewer words they knew," says Christakis. "These babies scored about 10% lower on language skills than infants who had not watched these videos."
It's not the first blow to baby videos, and likely won't be the last. Mounting evidence suggests that passive screen sucking not only doesn't help children learn, but could also set back their development. Last spring, Christakis and his colleagues found that by three months, 40% of babies are regular viewers of DVDs, videos or television; by the time they are two years old, almost 90% are spending two to three hours each day in front of a screen. Three studies have shown that watching television, even if it includes educational programming such as Sesame Street, delays language development. "Babies require face-to-face interaction to learn," says Dr. Vic Strasburger, professor of pediatrics at the University of New Mexico School of Medicine and a spokesperson for the American Academy of Pediatrics. "They don't get that interaction from watching TV or videos. In fact, the watching probably interferes with the crucial wiring being laid down in their brains during early development." Previous studies have shown, for example, that babies learn faster and better from a native speaker of a language when they are interacting with that speaker instead of watching the same speaker talk on a video screen. "Even watching a live person speak to you via television is not the same thing as having that person in front of you," says Christakis.
This growing evidence led the Academy to issue its recommendation in 1999 that no child under two years old watch any television. The authors of the new study might suggest reading instead: children who got daily reading or storytelling time with their parents showed a slight increase in language skills.
Though the popular baby videos and DVDs in the Washington study were designed to stimulate infants' brains, not necessarily to promote language development, parents generally assume that the products' promises to make their babies smarter include improvement of speaking skills. But, says Christakis, "the majority of the videos don't try to promote language; they have rapid scene changes and quick edits, and no appearance of the 'parent-ese' type of speaking that parents use when talking to their babies."
As far as Christakis and his colleagues can determine, the only thing that baby videos are doing is producing a generation of overstimulated kids. "There is an assumption that stimulation is good, so more is better," he says. "But that's not true; there is such a thing as overstimulation." His group has found that the more television children watch, the shorter their attention spans later in life. "Their minds come to expect a high level of stimulation, and view that as normal," says Christakis, "and by comparison, reality is boring."
He and other experts worry that the proliferation of these products will continue to displace the one thing that babies need in the first months of life — face time with human beings. "Every interaction with your child is meaningful," says Christakis. "Time is precious in those early years, and the newborn is watching you, and learning from everything you do." So just talk to them; they're listening.