The temptation to prop the nipper in front of Teletubbies and finally read Saturday's Family section on Wednesday is both understandable and, if the alternative is screaming at the little lovely out of exhaustion, probably preferable. But the truth is that few of us parents are aware of just how bad television is for their brain - too much is like feeding them mental uranium.
When boys are followed from birth until they are men, even after taking account of the other main causes of violence, like being beaten up or neglected, how much TV and how violent the content they watched as children remains an independent cause of how violent they are as adults.
Television makes us fat yet it also leads to self-starvation and throwing up food. Fiji did not have TV until 1995 and the women favoured a full figure. Not a single case of bulimia had ever been recorded there but within three years of the arrival of TV, 11% of young Fijian women were suffering. They were three times more likely to have developed the illness if they lived in a home with a TV.
Equally, TV causes obesity by increasing torpid inactivity, advertising fatty foods and increased eating while watching. Conclusive proof came from the introduction of TV in China, previously a thin population. Among 10,000 Chinese, the more they watched, the fatter they were. For every extra hour watched, the greater the likelihood of obesity.
It damages health in other ways. A 26-year study of 1,000 children showed that those who watched more than two hours a day between five and 15 were significantly unhealthier years later. Even after allowing for other factors, like social class and parents' habits, they were significantly more at risk of high cholesterol, smoking and unfitness as a direct result of their greater TV watching when young.
TV impairs children's concentration. For every extra hour a day watched, a child is 9% more likely to have attentional difficulties (the core problem in attention deficit hyperactivity disorder). To maximise the impact, there are shorter scenes: a study of the pace and editing speed in Sesame Street showed that they had doubled over a 26-year period. The duration of a typical American public service broadcast scene is 70% longer than one in a commercial children's TV show.
By fast-forwarding life into a concentrated rush of exciting events, TV corrupts children's expectations. Key reward chemicals are secreted, such as dopamine, and when the off button is pushed and they go to a school lesson, it's happening too slowly to maintain their interest: they want more, bigger snacks - now.
Children who watch a lot of TV before the age of three learn to fail academically: subsequent scores on maths, reading and comprehension are worse and their exam results are worse when recorded at age 26.
Knowing all this should make you take serious heed of the advice that children should watch no more than one hour a day. Yet the terrifying fact is that the average six-year-old has already spent more than one full year of its life watching TV. Half of three-year-olds have a TV set in their room.
The Department of Health should be mounting massive public-health campaigns to persuade us to watch less but that is unlikely to occur. So even if you are unable stop watching TV yourself (it is nurturing dissatisfaction with your body, your possessions and your lifestyle), today needs to be the first one in which your child only gets to spend an hour watching - and it needs to stay that way.
Review of evidence: Sigman, A, 2007, Biologist, 54, 12-17. See also Sigman, A, 2005, Remotely Controlled, Vermilion. More Oliver James at selfishcapitalist.com
