WASHINGTON, June 1 -- The more time infants and toddlers spend in front of the TV, the less exposure they have to adult voices and the less likely they are to speak themselves, researchers found.
The findings strengthen a suspected link between infant TV
WASHINGTON, June 1 -- The more time infants and toddlers spend in front of the TV, the less exposure they have to adult voices and the less likely they are to speak themselves, researchers found.
The findings strengthen a suspected link between infant TV exposure and delayed language development that previous studies have detected, according to a report published in the Archives of Pediatric & Adolescent Medicine.
While some believe audible TV is associated with decreased communication in young children, an entire market of educational DVDs geared toward babies has grown up under the opposite theory -- that programs can help promote interaction between parent and child.
Whatever the connection, infants are spending an increased amount of time in front the TV, according to a team led by Dimitri A. Christakis, M.D., M.P.H., of the Center for Child Health, Behavior and Development at the University of Washington.
A 2003 report from the Henry J. Kaiser Family Foundation found that each day, 68% of infants viewed some type of screen media: TV, DVDs or videos, computers, and video games.
For their study, the researchers recruited parents who agreed to wire their kids one day each month in order to record every sound from a 12- to 16-hour period.
Using noise-detection software that analyzed at least one recorded session from 329 kids between the ages of 2 and 24 months, the files were sorted into sounds the kids heard and sounds the kids made.
The researchers used a statistical model to determine the association between audible television and how many words were spoken each by the adult and the child. They also examined how many meaningful vocal interactions were shared by the child and adult while the TV was on.
They found that each hour spent with a TV on was associated with significant reductions in the child's vocalization.
Likewise, each additional hour of TV was linked with 770 fewer words that a child heard from an adult during the recording session -- a 7% decrease compared to the average number of words heard by kids in households where a TV is not on.
"Some of these reductions are likely due to children being left in front of the television screen, but others likely reflect situations in which adults, though present, are distracted by the screen and not interacting with their infant in a discernible manner," the researchers said.
The authors said that 30% of households have a TV on at all times, and that of course brings up the obvious question, "How many opportunities of child and parent vocalizations are being displaced?"
Previous research has shown that when adults are watching adult-themed programming -- even something that would be merely background noise for an infant, (such as the Jeopardy! Game show) -- they communicate less with their child, and their child makes less noise, said Deborah Linebarger, Ph.D., a researcher at the University of Pennsylvania, who has studied the effects of media on young children.
Dr. Linebarger was not affiliated with the study.
The authors of the latest report acknowledged that their findings seem obvious -- more TV time equals less human interaction. But they say it might also discredit the claims of companies that make DVDs for infants and market them as tools to promote interaction between child and parent.
Those claims are not backed by evidence, the authors said, adding that communicating with a child while the TV is on may be more important than the type of program to which the child is exposed.
The authors noted that as an observational study, causality cannot be determined.
Dr. Linebarger said her biggest criticism of the study is that it did not take into account what effect various types of programs have on communication.
She said her research indicates that shows designed for young kids that mimic the storytelling approaches of books are best at promoting language development.
Since 1999, the American Academy of Pediatrics has recommended that pediatricians discourage the watching of TV or other screen media by children younger than 2.
Previous studies have found that, in addition to the adverse effects it has on body weight, attention, and sleep, watching TV before age 2 harms a child's cognitive development and the uptake of language.
But a recent study published in Pediatrics found that watching TV before age 2 was not associated with cognitive development at age 3. (See Duration of TV Watching Has No Cognitive Effects on Children Under 2)
|The study was supported by the LENA Foundation, a nonprofit that develops technology for language research. Three of the study authors were employed by the LENA Foundation.|
Primary source: Archives of Pediatrics & Adolescent Medicine
Source reference: Christakis D, et al "Audible television and decreased adult words, infant vocalizations, and conversational turns" Arch Pediatr Adolesc Med 2009; 163: 554-58.