The 15% of the age group who watch television for more than three hours a day are at an increased risk of developing antisocial behaviours, such as fighting, stealing, or disobedience.
The research, published in Archives of Disease in Childhood, examined more than 11,000 children in Britain aged five and seven.
The children’s parents were asked to complete a “strengths and difficulties questionnaire” to describe how well adjusted their children were. They were also asked to report how much time their children spent watching television and playing computer games at the age of five.
The researchers found almost two-thirds of five- year-olds watched television between one and three hours a day, 15% watched more than three hours, and less than 2% watched no television at all.
After taking into account variables including parenting and family dynamics, the researchers found watching television for three or more hours a day led to a small but significant increased risk of antisocial behaviours.
But spending a lot of time watching television was not linked to other difficulties such as emotional problems.
The authors, from the University of Glasgow, also found time spent playing computer games had no impact on behaviour.
They found “watching television, videos, or DVDs for three hours or more daily was associated with a small increase in conduct problems between the ages of five years and seven years, after allowing for other child and family characteristics, including parenting”.
But they said: “Our findings do not demonstrate that interventions to reduce screen exposure will improve psychosocial adjustment.”
Indeed, the researchers suggest interventions in respect of family and child characteristics are more likely to improve outcomes.
“However, the study suggests that a cautionary approach to the heavy use of screen entertainment in young children is justifiable in terms of potential effects on mental well being, particularly conduct problems, in addition to effects on physical health and academic progress shown elsewhere.”
Sonia Livingstone, social psychology professor at the London School of Economics, added: “If five- year-olds watch more than three hours of television per day, research detects a small but noticeable negative effect on their conduct problems, though no effect on hyperactivity or emotional problems.
“So, no cause for panic, but good reason to ask why some children spend so much time watching television — perhaps the pressures on their parents are too great, or perhaps there are no play spaces nearby?
“Or maybe what matters is how children watch television — research also shows that children benefit the most from opportunities to talk, interact, and play — and this can be done in front of the television as well as elsewhere.”