Read the headlines, and you’ll see plenty of hand-wringing about screen time – that we’re too engrossed with our smartphones and that it’s damaging our health and our connections to others. But moral panic about a new technology is a tale as old as time – think television, radio and the printing press before it.

Does the scientific evidence bear out our concerns around screen time? Well, maybe – according to a new study of young North American children.

In this study, the researchers looked at data from the Adolescent Brain Cognitive Development Study – which is a large study that has been collecting information on the cognitive abilities of children between the ages of 8 and 11 since 2016.

The researchers measure a child’s “global cognition” – akin to IQ – which includes things like their memory, attention and language abilities. It also looked at their “fluid intelligence” (flexible ability to learn new things in an unfamiliar environment) and “crystallised intelligence” (knowledge gained from past experiences).

Importantly, they also measured how physically active the children were, how long they tended to sleep at night, and their recreational screen time. These were benchmarked against three movement guidelines for children: an hour of physical activity a day, two hours or less of recreational screen time, and between 9 and 11 hours sleep.

Among the more than 4000 children, they found that only half were meeting the sleep recommendation, 37 per cent were getting fewer than two hours of screen time, and only one in five got enough physical activity. Only five per cent of kids met all three of the recommendations. What’s more, those factors did seem to be linked to cognitive ability.

Those who met all three recommendations had superior cognitive ability compared with those who met none, and there were also benefits for those who met just the screen time recommendation, or had lower screen time in combination with better sleep. Curiously, they didn’t see a link between more physical activity and better cognition, which goes against what other evidence says on the subject.

Implications

Those anxious about screen time may have a point. Probably as important as the activity itself is what it displaces – more screen time means less time for a child to run around or read a book. No need to panic, but being mindful about how long your kids spend in front of the screen seems wise.

Last Reviewed: 01/02/2020

© Norman Swan Medical Communications.



References

For reference: Walsh, et al. (2018). Associations between 24 hour movement behaviours and global cognition in US children: a cross-sectional observational study. The Lancet Child & Adolescent Health doi: 10.1016/ S2352-4642(18)30278-5.

%d bloggers like this: