Report: More than two hours’ screen time bad for kids
Laura Donnelly
Children who spend more than two hours a day looking at a screen have worse memory, language skills and attention span, a landmark study has found.
The research, which involved children aged between eight and 11 found that those with higher amounts of recreational screen time on smart phones and playing video games had far worse cognitive skills across a range of functions.
The research, published by the Lancet Child and Adolescent Health, tracked the daily habits of 4500 children who were then asked to carry out detailed cognition tests.
The study found that more than two hours a day of recreational screen time was associated with worse working memory, processing speed, attention levels, language skills and executive function.
The study of US children, led by the University of Ottawa, questioned thousands of parents and children on their daily habits — including time spent sleeping, using smartphones and other devices, and levels of physical activity.
Overall cognition skills were best among the one in 20 children who got between nine to 11 hours sleep, less than two hours recreational screen time, and at least an hour’s exercise daily.
These children did around 5 per ● British guidelines, set out by the National Institute for Clinical Excellence, recommend no more than two hours’ leisure screen time a day for children of any age.
● In the United States, it is recommended that children under 2 have no screen time at all and no more than two hours a day for children over 2.
● In France, it is illegal to market TV shows specifically to children under 3.
● In Taiwan, parents are legally obliged to monitor children’s screen time. They are fined T$40,000 ($1965) if they are found to be letting an under-18 have a screen for hours at a time.
cent better in the tests than the average child. The study isolated screen time as the likely key factor. Children who were glued to their screens for less than two hours per day saw performance around 4 per cent better than the average among their group, regardless of other habits.
Lead researcher Dr Jeremy Walsh said: “These are landmark findings. We’ve set a clear two-hour benchmark here and it shows clear cognitive benefit is associated with keeping within that limit.
“I think parents should now be looking closely at screen time and this suggests it should be limited to two hours a day.”
The findings are from an observational study, meaning it was not possible to prove that extra time on devices caused the weaker cognitive
skills. But experts believe several factors — the impact of blue light on the brain, the online activity itself and the fact time spent on gadgets eats into time which might otherwise be spent exercising, sleeping or taking part in more social or mentally challenging tasks — could explain the links.
Until now, experts have argued about a lack of clear evidence about the impact of screen time.
Walsh said more research was needed to examine the potential impact of different online activities.
In the meantime he urged parents and health officials to consider two hours recreational time online as the maximum daily limit.
“We found that more than two hours of recreational screen time in children was associated with poorer cognitive development. More research into the links between screen time and cognition is now needed, including studying the effect of different types of screen time, whether content is educational or entertainment, and whether it requires focus or involves multitasking.
“Based on our findings, paediatricians, parents, educators, and policymakers should promote limiting recreational screen time and prioritising healthy sleep routines throughout childhood and adolescence,” he said.
Dr Eduardo Esteban Bustamante, from the University of Illinois, said the findings suggest that too much screen time could mean children’s brains had too little time to recover from the strain of each day.
“Each minute spent on screens necessarily displaces a minute from sleep or cognitively challenging activities. In the case of evening screen use, this displacement may also be compounded by impairment of sleep quality,” he said.
The study found that children in the United States spend an average of 3.6 hours a day engaged in recreational screen time. The research controlled for household income, parental and child education, ethnicity, pubertal development, body mass index and whether the child had had a traumatic brain injury.
In the study, families were given questionnaires to see how many children aged 8 to 11 get nine to 11 hours sleep, less than two hours’ recreational screen time, and at least an hour’s exercise daily.
The study found 29 per cent of children achieved none of the three recommendations, while 41 per cent met just one, 25 per cent met two and just 5 per cent met all three.
Just over half of the children met the sleep recommendation, while around one third met the screen time recommendation, and 18 per cent met the physical activity recommendation.
While achieving all three was associated with the best performance in the tests, when individual factors were examined levels of physical activity made little difference, with the strongest association linked to screen time.