Teenagers who watch television several hours a day may perform worse in their study, suggests a new study that claims to be the first one to link increased TV viewing to academic failure.
Previous studies have also connected television to poor academic performance. However, in the new study, Jeffrey Johnson of the New York State Psychiatric Institute, the US, and colleagues studied the TV habits of 14-year-olds from 678 families in the upper regions of the US.
The researchers also asked the teens' parents whether the youngsters had any behavioural or academic difficulties. The researchers continued collecting information from the parents and interviewed the teens again at age 16, and again at ages 22 and 33.
The 20-year study, begun in the mid of 1980s, found that at age 14, most of the children watched between one and three hours of television each day, while 13 percent watched more than four hours, and 10 percent watched less than one hour. Their viewing habits remained nearly identical at ages 16 and 22.
Johnson's team found that 30 percent of students who watched more than three hours of television at age 14 had attention problems in subsequent years. By comparison, only 15 percent of those who watched less than one hour of TV at age 14 showed the same attention deficits later on, reported online edition New Scientist.
Nearly one-third of those who watched many hours of television fell behind or failed to graduate by age 22. By comparison, only 10 percent of the teens who watched less than an hour of TV a day went on to perform poorly in school or drop out.
Those who watched three hours or more hours of TV had an 82 percent greater chance of not graduating or falling behind compared with teens who watched less than an hour - even after accounting for other factors, such as any learning difficulties the teen had at age 14 and socio-economical status.
Teenagers who watch several hours of television a day do worse at school and are less likely to graduate than their peers, the study said.