Kids and Technology: What the Research Says

Published March 19, 2020   |   

Each year the call to restrict technology for children and teens gets more urgent, as researchers and child advocates warn parents against the evils of too much “screen time.” And, given the way technologies like artificial intelligence are transforming our daily lives, a certain level of concern is understandable. As a result, social media and smartphones are regularly blamed for social ills like the recent rise in teen depression and anxiety.

But research into the impact of technology is still in its infancy. And showing a direct link between technology use and childhood obesity and depression is a hard one to make. Still, there is enough preliminary research to suggest that screen time and social media are having some level of impact on kids today. The question is how much.

Physical Changes in the Brain

One big concern among child advocates is the amount of time children and teens spend on smartphones, tablets, and other devices. Several early studies suggest that too much screen time affects the cognitive and physical development of babies and young children. That is, excessive screen watching may be physically changing the structures of their brain.

One ambitious study launched by the National Institutes of Health is trying to understand how screen time affects the physical structures of the young brain. Over the course of a decade, the NIH plans to study over 11,000 children up to adulthood. In the study’s first wave, researchers scanned the brains of 4,500 children and recorded their screen time consumption. The results showed a thinning of the cerebral cortex for those children with more than seven hours of screen time per day. The cerebral cortex processes information from our five senses.

In a much smaller JAMA published study, researchers studied the brain development of prekindergarten children with screen use greater than the American Academy of Pediatrician’s recommendations. Scans showed smaller regions of “white matter” in the brain — a section that supports language skills. Unsurprisingly, those same children scored lower on subsequent literacy skill tests.

Although both studies show associations, neither could demonstrate a direct link to screen time usage and brain changes. It’s still too early to say what the results mean for childhood cognitive development and later adult life.


The less physical activity a child gets, the more likely they’ll be obese. And those who spend hours watching YouTube videos or scrolling through Facebook feeds are usually sedentary. The association between screen time and obesity has been an interest of parents and pediatricians since the mid-80s when fears of too many hours of MTV watching and Atari playing were thought to contribute to overweight children. Today, those same fears are at the forefront of research into technology and children.

One recent study published in the Journal of Pediatrics showed that a five-hour-per-day screen time habit raised the odds of obesity by 43% in teenagers. And a 2019 meta-analysis of 16 similar studies concluded that increasing screen time beyond two or more hours each day could be a risk factor for obesity in children.

The problem with making a direct link between obesity and screen time is the myriad of genetic and environmental factors at play. Many kids eat while watching TV or playing video games. The more they watch, the more they eat. So, in addition to substituting screen time for physical playtime, children tend to consume more calories while watching screens. And all that screen time means kids are also seeing thousands of ads for food and drinks. That in-screen marketing then reinforces the desire to consume. Finally, add the fact that screen time also disrupts sleep — which also leads to weight gain — and you’ve got a perfect storm for obesity.

Sleep Disruption

If sleep quality was the only thing that technology affected, it would be enough to concern parents. That’s because sleep is so integral to a child’s health and wellbeing. And, without a doubt, electronic devices contribute to sleep problems for children. One survey of 67 sleep studies conducted between 1999 and 2014 found that 90% of them could link screen time with poorer sleep quality in children. And there are several reasons for this.

First, electronic devices like tablets and smartphones emit an ambient blue light. Exposure to artificial blue light suppresses the release of melatonin, the body’s sleep-inducing hormone. Too much exposure, especially before bedtime, interferes with a child’s circadian rhythms, which tells them when to wake and when to sleep. That’s why child experts advise parents to take devices away at least an hour before bedtime.

Then, there’s the fact that electronic devices are a source of 24-hour entertainment easily consumed in bed. Kids can’t fall asleep because they’re constantly engaged by videos, pics, and messages. And even when they do fall asleep, that Pavolvian vibration or “ding” of a just-received message prompts many to wake from slumber to check an incoming message.

Depression and Anxiety

Rates of depression and anxiety among adolescents 12 to 17 are trending upwards. And television and social media are part of the problem, according to a recent study of 4,000 Canadian teens. Researchers followed the teens for four years, recording the time they spent on digital screens and having them self-report feelings of depression. In the end, researchers found that just one-hour annual increase in social media or TV watching was associated with more severe depression and lower self-esteem.

Interestingly, the study didn’t find a rise in depression with other screen activities like computer use or playing video games. Researchers attributed the discrepancy to the lack of personal comparison that video gaming and general computer use have. Social media and television both bombard teens with unrealistic images and lifestyles of other people. One’s comparison to these idealized images is thought to contribute to lower self-esteem and depression, especially in girls who use social media at higher rates than boys.

It’s Not All Bad News

So far, reports on technology and children seem mostly negative. But there are positives too. The fact is children don’t just use smartphones and computers to play video games or chat online. They also use them to create and inspire each other, to connect with people, and to learn.

The term screen time isn’t some monolithic concept you can use to describe every interaction with technology. While pediatricians warn new parents to leave screens out until 18-months, they also recommend video conferencing apps for young kids who need to socialize with remote family members. In fact, these moments of socialization are critical to a child’s emotional and social development. So “screen time” is a nebulous term that still needs defining by social advocates and researchers.

And while it’s easy to see some problems as natural outcomes of too much technology, the connection to other social ills isn’t as clear cut. Most studies like the ones mentioned above are correlational, meaning they can only establish an association, not a cause-and-effect. For example, it could be that kids who are already depressed are also more likely to seek out social media, instead of the other way around. It may be the case that smartphones are causing a lack of sleep, which leads to depression. But it’s also possible that they could be causing depression, which leads to a lack of sleep.

More time and research is needed to establish causation. And from a scientific standpoint, patience is a given for performing thorough research. But for parents afraid their children are being irreparably harmed, patience is, understandably, in short supply.