Researchers from Newcastle University and Queen Margaret University, Edinburgh, found that children who watch less than three hours of TV a day when they start in primary school are more likely to communicate their ideas effectively when they move on to secondary school.
Using data from thousands of children in the UK's Millenium Cohort Study, the research team showed that while less is generally better than more when it comes to watching TV, the impact varies, depending on the child's language skills at 11 years.
While it appears to make little difference to the children who have higher language scores, by contrast more than three hours of TV a day is strongly associated with poorer language skills later on.
Helping children to develop good language skills
The researchers looked at the impact of parental involvement with children when they were aged three and five-years-old and then examined how well they were able to communicate their ideas at 11.
They asked parents how often they read to their children, told them stories, visited the library together, took them to the park or watched television together – for three hours a day or less
Reading to young children was, on average, associated with better performance but again it had much less of an effect for children with the best language scores at 11 years and correspondingly much more of an effect for those who were doing less well.
Lead researcher James Law, Professor of Speech and Language Sciences, in Newcastle University's School of Education, Communication and Language Sciences, said: "As researchers, we're really interested in looking at the things which parents can do which can make a positive impact on helping their child develop good language skills.
"The television effect was a very interesting finding and we saw it had a bigger impact for the children with lower language skills, but made little difference to those who had higher levels of language.
"Television isn't the enemy. My personal view is that it's how you watch it that's important. If you're actively watching a programme with your child and you're talking about what's happening, you're asking and answering questions, then I think that's fine and it will be a positive experience for both of you.
"It's when children are sat in front of it for hours with no input – in effect an electronic babysitter - that I think it becomes problematic."
Explore further: Study concludes parents mixing languages has no impact on children's language development