New York, March 3: Watching television before age 2 doesn’t boost or hinder toddlers' mental development, a study released Monday suggests.

The study conducted by the scientists at Harvard University and Boston’s Children’s Hospital shows that the amount of time spent watching TV doesn’t hurt or help brain development before the age of two.

"Contrary to marketing claims and some parents' perception that television viewing is beneficial to children's brain development, no evidence of such benefit was found," said the study's lead author, Marie Evans Schmidt, a research associate at the Center on Media and Child Health at Children's Hospital in Boston.

To reach their discovery Schmidt along with colleagues from Harvard Medical School analyzed data of 872 youngsters from Project Viva, a prospective cohort study of mothers and their children.

The researchers looked at how long the children watched TV or DVDs before they reached two years of age, and recorded their performance on language and motor skill tests at age three.

The study children, who were assessed at birth, six months of age, and then again at age 3, were given the Peabody Picture Vocabulary Test III (PPVT III) and Wide-Range Assessment of Visual Motor Abilities (WRAVMA) test to measure their verbal and motor skills at age six months and three years.

Mothers of the children were also asked to complete questionnaires on the baby's TV-viewing habits at six months, one year and two years. On average, mothers reported that their children spent 1.2 hours a day watching television.

After adjusting the data for sociodemographic and environmental factors- such as mother's age, education, household income, marital status, as well as child's body mass index, gender, race, birth weight, sleep habits and duration of breastfeeding, Schmidt and colleagues found that TV viewing wasn't linked to improvements in vocabulary testing or in visual motor abilities tests.

"In this study, TV viewing in itself did not have measurable effects on cognition," says Schmidt. "TV viewing is perhaps best viewed as a marker for a host of other environmental and familial influences, which may themselves be detrimental to cognitive development."

Results of this study reaffirm current guidelines from the American Academy of Pediatrics (AAP) that recommend children younger than 2 never watch screen media, and suggest that maternal, child, and household characteristics are more influential in a child's cognitive development.

But, the latest surveys show that more than two-thirds of American kids under two watch TV daily.

"We didn't find any evidence of harm, but I want to be quick to point out that we didn't find any evidence of benefit either," Schmidt said of his study. "We don't want this to become a license for parents to put babies in front of the TV.

“We know the results run counter to the perception a lot of parents have about TV. A lot let their babies watch TV because they think it's good for their brain development."

The study authors warned that despite these results, the evidence suggests that watching TV before the age of two could be more harmful than beneficial.

"TV exposure in infants has been associated with increased risk of obesity, attention problems, and decreased sleep quality," said study co-author Michael Rich, MD, MPH, the pediatrician who directs the Center on Media and Child Health. "Parents need to understand that infants and toddlers do not learn or benefit in any way from viewing TV at an early age."

Findings of the latest study appear in the March issue of the journal Pediatrics.