LONDON: Adolescents who watch too much TV develop learning problems and are less likely to go to university, according to a study that followed nearly 700 children for 20 years.

In the study, 14-year-olds who watched more than three hours a day were twice as likely not to continue their education after school as children who watched less than an hour. The researchers believe that watching too much TV makes other activities such as reading and homework more boring and challenging.

“Adolescence is known to be a ‘critical period’ for the development of many important cognitive skills. In this context, it is very understandable that, if youths spend more of their free time watching TV ... rather than reading, doing homework and having other valuable learning experiences, the development of their cognitive skills may be inhibited,” said Jeffrey Johnson at the Columbia University College of Physicians and Surgeons in New York, who led the research team. The average 11- to 15-year-old in Britain is in front of a screen for seven and a half hours a day.

The study is authoritative because it rules out the effects of children having poor attention and learning problems for other reasons as well as the influence of their socio-economic status.

The researchers were able to show statistically that excess TV viewing appears to lead to poor academic achievement, rather than the other way round. They could do this because they factored the children’s learning abilities at the start of the study into their analysis. The team first selected volunteers from a range of socio-economic backgrounds in New York State in 1975. Subsequently, the team assessed the children’s TV habits and educational performance at age 13, 16, 22 and 33.

Dr Johnson said he believes that the brains of children who watch lots of TV become accustomed to rapidly changing visual stimuli which do not require much intellectual effort. That might make other activities such as reading and listening in class more difficult to concentrate on, and more boring. “Our findings indicate that youths who frequently watch TV may develop problems such as classroom boredom, ‘hating school’ and difficulty doing homework — all of which may be in part a result of having become habituated to frequently changing and highly stimulating material on the TV or video screen,” he added.

Among children who showed no signs of learning problems at the start of the study, the team found that 22 per cent of children who were watching more than three hours of TV a day at age 14 did not go on to higher education. For those who had watched less than one hour of TV a day that number was seven per cent.

The equivalent figures for children who had learning problems at the start of the study are 45 per cent and 29 per cent. The study is published in the Archives of Paediatric and Adolescent Medicine.—Dawn/The Guardian News Service