The study looked at 1,864 participants at age 6 months and every year from ages 1 to 7. Mothers reported the child’s average TV watching and sleep duration.
The study concluded that for each additional hour of television watching, children got seven minutes less sleep per day. Even that small amount of decreased sleep could be detrimental, according to presenter Elizabeth Cespedes of Harvard’s School of Public Health.
“Modest decreases in sleep due to TV [watching] or bedroom TV could lead to sleep deficits,” which can have major impacts, she said.
The study’s authors found that television viewing creeps up in duration over time, as does the presence of televisions in children’s bedrooms, which rose from 17 percent at age 4 to 23 percent at age 7. Racial and ethnic minority children were more likely than white children to have televisions in their bedrooms.
The difference in sleep effects of having televisions in the bedroom was clearest when white children were compared to racial and ethnic minority children, researchers found. Minority children with televisions in their bedrooms were estimated to get a full half hour less sleep than white children without televisions in their bedrooms.