The television is constantly on in our home. I'm pretty sure it's doing more harm than good to my children, particularly when they are trying to read or do their homework. Is there any research that proves I'm right? Katherine Forestier, education editor, responds: You are not alone. Research statistics suggest that Hong Kong children watch more than three hours of TV a day. And it is not difficult to find ample research that proves you're right. Hundreds of studies have linked TV with a wide range of problems for children - attention deficit disorder, aggressive behaviour and bullying, smoking, obesity, early sexual activity and poor school performance. The American Academy of Pediatrics is so concerned that it recommends children watch no more than two hours a day, and those under age two watch none at all. New Scientist magazine recently reported on studies published in the July issue of Archives of Pediatric and Adolescent Medicine which showed TV reduces children's learning ability, academic achievement and even their likelihood of graduating from university. Robert Hancox of the University of Otago in New Zealand and colleagues studied nearly 1,000 children born in Dunedin, New Zealand, in 1972 and 1973. The researchers gathered data from both parents and children on how many hours a day were spent watching TV at age five, seven, nine, 11, 13 and 15. The team then re-evaluated participants at the age of 26. Children who watched the least TV had the highest probability of graduating from university by the age of 26, regardless of IQ or socio-economic status. Those who watched the most, more than three hours per day, had the highest chance of dropping out of school. Other studies published in the same journal echoed these findings. Dina Borzekowski at Johns Hopkins Bloomberg School of Public Health and colleagues found that Northern Californian third-graders - aged about eight - with a TV in their bedroom watched more TV and did worse on standardised tests than those without a bedroom TV. A University of Washington in Seattle study linked TV watching before the age of three to poor reading and maths at ages six and seven. TV is thought to reduce educational achievement by taking time away from creative play, reading or doing homework. It is also suggested that its fast but passive nature slows brain development and affects children's ability to concentrate. Frequent exposure to violence is blamed for desensitising emotions to suffering and acts of violence. Psychologist and child brain expert Jane Healy has said that the constant noise of TV may interfere with the development of children's 'inner speech' by which they learn to think through problems and restrain impulsive responses. That said, I've found that limited and highly selective TV viewing can be positive, particularly when children act on what they watch, for instance by creating an 'Art Attack', cooking up a Jamie Oliver recipe or discussing new or controversial information gleaned from the box. Visit www.abelard.org for access to some of the research quoted.