Dr Sigman, who is an Associate Fellow of the British Psychological Society and a Member of the Institute of Biology, says that the research shows too much TV can contribute to a range of childhood physiological and mental health problems.
By the age of 6, the average British child has spent one complete year in front of a screen, mostly the TV.
And the average adult will have spent 12 solid years in front of the box by the time he or she reaches 75.
Dr Sigman has found evidence that too much TV watching causes short-sightedness and disrupts hormonal balance and leads to increased risk of cancer and premature puberty. It also slows down the metabolism which is linked to increase in obesity and type 2 diabetes.
Mental problems linked to too much TV viewing include autism, poor concentration and Alzheimer’s in adulthood.
Dr Sigman’s advice is that children under 3 years old should not watch any television, while those aged 3 to 5 should only watch half an hour a day at the most. Older kids should be limited to no more that one hour a day.
He mentions one research paper from Florence University where scientists found that screen based computer games and TV watching reduced levels of melatonin in the children’s blood, a condition that is thought to trigger early puberty.
Dr Sigman has called for TV viewing to be restricted before. In October 2005 there were reports in the media that he was calling for recommended daily allowances for TV viewing. Teenagers should watch no more than one and a half hours a day and adults two hours, he said.
His recommendations were criticized by experts as being unworkable and unrealistic.
On the other hand, there are experts who argue that TV can help with learning and even promote health through giving people information that they might not otherwise come across.
For instance, last year researchers at the University of Chicago found that preschool television exposure had no negative effect on school performance and earnings in later life and may even enhance these factors. Their study was called “Does Television Rot your Brain?”
They found a slight increase in school test scores occurred for an additional year of preschool television. And this was particularly marked in families where English was not the first language, where mothers had less than a high school education, and for non-white children.
Their conclusion was that “the introduction of television in the 1940s and 1950s had, if anything, positive effects on the achievement of students exposed to television as preschoolers.”
Alarmed parents burdened with yet more conflicting advice on how to raise children, and wondering how they are going to manage in a world where TV and the screen dominates every day life, may take comfort in the advice of many psychologists and experts. They say yes, be sensible and by all means limit your child’s viewing, but the most harmful thing you can do is leave a child to watch TV on his or her own for hours on end.
They would encourage you to use TV and computers to enlarge your child’s experience, and to develop a healthy curiosity about the world around them. They would say supervise what they watch and help them to make sense of it. Try not to use TV as a “parent substitute”, although even the best intentioned parents are guilty of that sometimes.