Screen Time And Child Brain Development — Here’s The Latest Research

Updated Jan. 10, 2024 at 6:35 p.m*

BERLIN — Every parent I know occasionally lets their child use their cell phone or tablet, even if they are under the age of 3. And they all have a guilty conscience. But as a parent, you also want to comb out your child’s knotted hair or finish eating in peace. Besides, we live in the digital age, where screens are everywhere anyway. Just a few minutes surely can’t be that bad.

Or can they?

This “or can they?” also concerns scientists. Researchers are looking into the physical, cognitive and social consequences of 0- to 3-year-olds using smartphones or tablets on their own. Their initial findings are worrying.

The more time a two-year-old spends in front of a screen, the higher their body mass index (BMI). Researchers in Sydney, for example, measured this back in 2014, with their young test participants spending an average of almost five hours a week in front of a screen. The health problem: an elevated BMI is a risk factor for developing Type 2 diabetes.

Worldwide, myopia (nearsightedness) is the eye disease with the fastest-growing rate of affected individuals. Prolonged staring — such as at a screen — is considered a significant cause, especially at an age before the eyeballs are fully grown. That means at an age younger than 4 years. While children also stare when reading books, 2-year-olds don’t do that yet.

Children who use screens also sleep worse, and sleep plays a crucial role in learning. If its quality decreases, the brain cannot develop optimally and performs less effectively — resulting in children processing and memorizing experiences or learned information less efficiently.

Poorer brain performance

Last year, a research group from Singapore illustrated the development of children’s brains in relation to screen use through electroencephalograms: Children who did not use digital media as babies and toddlers were ahead in brain activity compared to peers who spent a lot of time — up to several hours daily — in front of screens. The researchers found this developmental delay not only during toddlerhood. They demonstrated it both at 18 months of age and much later, at school age around 9 years old.

The more a toddler engages with a screen, the less they crawl, kick and turn.

The more a toddler engages with a screen, the less they crawl, kick and turn. Later, they also climb, balance and jump less often, simply because digital media rob time for such activities. As a parent, one might say: So the child learns to walk, hop and climb a few weeks later, where’s the problem?

But brain research shows that walking, hopping and climbing don’t only train balance and body awareness, but also activate areas in the brain responsible for cognitive tasks like understanding, remembering and speaking. This connection can also be tested: Children with poorer gross motor development also achieve poorer results in cognitive tests.

2D vs 3D

As a parent, you might wonder how this can be. Why should it be harmful for a child to watch animal videos, for example? If they’re well-made, aren’t they perhaps even educational?

David Martin, a pediatrician at Witten/Herdecke University, has been studying the consequences of screen media use for children under three for years. During a video call, he illustrates the problem: “Even if I only see you on the screen, I know that the dark area on your head is hair and how it would feel if I touched it. I know that the window sill behind you continues, even though I only see it to your right and left. I know that the blue rectangle at the very top is the sky. I know all this because I have acquired this world knowledge in the three-dimensional world.”

A toddler has to learn this first — and that doesn’t happen in two dimensions.

The phenomenon has been known since the 1970s and is now referred to as the Video Deficit Effect. Research teams have repeatedly observed 2-year-olds watching an adult hide a toy in a room in experiments with slightly modified test procedures.

Children literally have to grasp the world first.

One group of test children observes the process directly in the same room, the other only via a screen. Children in the first group are then able to find the toy, while children in the second group are not. They cannot make the transfer from two to three dimensions. This starts working from about 3 years of age.

“Children literally have to grasp the world first for the brain to comprehend it,” Martin says. Screens are unsuitable for this. According to Martin, the consequences are “catastrophic.” What this catastrophe looks like can be seen in images of healthy preschoolers’ brains taken by U.S. researchers. The images show both gray and white brain matter. The more intensively a child had engaged with digital media, the smaller and less functional the structures were.

Martin is very keen to make parents aware of such consequences when their baby handles a screen, even if it’s not for hours, but only a few minutes a day. He is therefore co-author of the medical guideline “Prevention of Dysregulated Screen Media Use,” which recommends that parents keep their child away from any display until the age of 3.

The American Academy of Pediatrics (AAP) and the World Health Organization (WHO) recommend similarly strict measures: Children up to the age of 2 should never be left alone with digital screens. From 3 years old, a maximum of one hour per day — and only accompanied by an adult. The only exception: video calls with grandma or grandpa.

Research not so clearcut

It’s worth delving deeper into the state of research, with the help of an expert. Sabina Pauen is a professor of developmental psychology and researches mainly category and concept acquisition as well as causal understanding in early childhood at the University of Heidelberg.

In other words, she investigates how children learn to understand the world. She also deals with self-regulation and the social-cognitive development of young children through interactions. In short: Everything that could be relevant to the question of how harmful the use of digital screens is for very young children.

She warns against jumping to conclusions about the dangers of screens for toddlers. Pauen notes that the state of research is anything but clear-cut. Often, for example, the data basis is very thin. For instance, while the images of toddlers’ brains from the U.S. study are impressive, and the conclusion that the brain structures of children who spent a lot of time in front of screens appear less large and less capable is correct, only 47 children were examined.

Nothing can be deduced about causal factors from such correlative studies. Forget it.

Moreover, the young subjects had above-average screen use. What other potentially relevant factors could have played a role? How stimulating do the parents make family life? What eating habits do they have? The researchers don’t address these questions. “Nothing can be deduced about causal factors from such correlative studies,” says Pauen. “Forget it.”

The topic of screen time for children is a broad field, almost unmanageable for researchers. There are smartphones, tablets, laptops, children’s computers and televisions that have been around for decades. What can be seen there ranges from texts to images and films to interactive games.

There is content of all levels for adults and now also for children. The diversity of media, their forms, content and use makes scientific investigation complicated because comparison is complicated. For valid statements, researchers also need time. A lot of time, at least more than rapid technological progress often allows them for long-term studies.

Screen use becoming higher in toddlers

Another difficulty for researchers nowadays is finding comparison groups of children who grow up completely without screens. In Germany, almost all households have internet, Wi-Fi and smartphones. And the number of young children up to 3 years old who not only use digital devices but already have their own is continuously increasing: 10 years ago, only 3% of children had their own computer. Today, 21% do.

But regardless of whether it’s on their own device, that of their parents or their older brother’s, on average, today’s 2- and 3-year-olds watch more than an hour of films, videos, shows on some kind of screen — each day.

Researchers must therefore constantly create more sophisticated study designs. They would also have to work with the largest possible cohorts and equally large comparison groups, which also bring similar framework conditions in terms of age, time, content of media use, as well as their socioeconomic background and health status, for the collected data to be meaningful at all. This is simply hardly feasible.

Serious researchers are aware of these difficulties. That’s why, for example, the team that recorded the impressive images of brain activity in relation to screen use by young children in Singapore writes: “Further efforts are urgently needed to investigate the direct relationship between children’s screen consumption and family factors.”

And even if a study is well-conducted, scientifically sound and transparent, there’s still the task of weighing and interpreting the results. For example, the study on children’s increased BMI does show a correlation with their screen time and therefore a greater risk of Type 2 diabetes. But the same data also shows that birthweight and length, as well as how long the child was subsequently breastfed are much more relevant for this health risk. So if a mother feeds both herself and her baby healthily, that’s much more crucial for her child’s development.

Not a reward

Does this data situation mean absolution for parents who occasionally hand their 2-year-old a smartphone, or are these parents actually jeopardizing their child’s well-being? Pauen initially responds with the admittedly interpretable but also incredibly relieving sentence: “It depends.”

The researcher doesn’t concur with the drastic demands for absolutely no screen use. She is convinced that parents feel offended by the radical demand for total abstinence — and then completely shut down instead of consciously dealing with the topic of screen time. But that’s crucial. Because besides all the possible physical and neurological consequences, spending a lot of time in front of a screen can also have emotional-psychological effects on a child.

What these are depends not only on the absolute duration but also on the how. On the one hand, using digital screens affects a child’s self-regulation. Learning to deal with one’s feelings — especially unpleasant ones like anger and frustration — is an important process.

Parents should absolutely avoid using the tablet or phone as a reward or comfort.

“However, if I as a child learn that ‘When I’m bored or frustrated, I turn on my tablet,’ that’s an avoidance mode,” explains Pauen. “And that ultimately worsens the problem because the child doesn’t learn more suitable strategies for regulating unpleasant feelings.”

For this reason, parents should indeed absolutely avoid using the tablet or phone as a reward or comfort. “It’s like with sweets,” says Pauen. “If you declare something as a reward, the child associates it with pleasant feelings — and will later crave it all the more intensely.”

This can develop into a real vicious cycle. If a child spends a lot of time in front of a screen, it will lead to new frustration situations on other levels — poorer school results, for example — and then the child will reach for the phone or tablet even faster to escape the newly created frustration again.

Parents’ screens

An important factor in this complex learning process for babies and toddlers is the experience of seeing their own emotions reflected in their parents’ faces. Anyone who has ever leaned over a baby knows this: You automatically imitate their facial expression.

This is not a cute coincidence, but vital for the child. It teaches them to read and interpret faces and that emotions can be shared with other people. What they feel matches what they see. A cell phone display can severely disrupt this feedback. Which brings us to the parents’ cell phone.

If you secretly look at your own screen in front of your baby, your face will reflect your reaction to whatever you are looking at — and not to your own baby. This creates a discrepancy that a child cannot interpret. A baby can’t understand why mom is smiling when she is grimacing because she is cold. And it can’t see the funny meme that she has just received on WhatsApp.

Children who are regularly exposed to such situations react confused and stressed, and in extreme cases aggressively. Researchers refer to this relatively new disorder of parent-child interaction as technoference. Pauen is also planning an experimental study and wants to install a camera on her office window. This will record all the parents push a baby carriage on the sidewalk below the window.

It sounds as if you’ve already done something wrong as a parent if you type a reply back to your friend’s message even though you’re breastfeeding or giving your baby a bottle. This is happening more and more frequently. “Unfortunately,” Pauen says.

Developing parental care

Pauen explains matter-of-factly: Humans are creatures that have certain needs and are dependent on others responding to these needs. A baby cannot communicate its needs verbally. It is particularly dependent on the adults around it noticing what it needs. If parents don’t look and listen, they won’t notice. And this doesn’t just apply to a single, specific moment.

Humans do have a predisposition for parental care. But when we become parents, we also need to develop this further — in continuous interaction with our child. Those who have little interaction miss out on important opportunities to learn to understand their child.

The world has been digital for a few decades now. As parents, there’s no getting around it.

So if you really need to respond to emails or do something on the computer or cell phone, you are better advised to clearly signal this to your child and then not be available for this time. The boundary can be another room or at least a clear turning away. Working from home is a particular challenge in this context, and good childcare is simply necessary for this reason, too. The world is what it is, and it has been digital for a few decades now. As parents, there’s no getting around it.

So if you give a screen to very young children, then please do it as consciously as possible, not as a reward or consolation and above all, use the screen together.

Adapting to screens?

At the end, the professor of developmental psychology puts forward a hypothesis that gives every stressed parent hope: She believes it is possible that we humans could adapt to digital circumstances.

Just as we quickly learned to focus on our eyes to interpret facial expressions in the face of all the mask-wearing people during the pandemic, we could also adapt to the modern human behavior of looking at screens.

This hypothesis may be supported by the experiment in which 2-year-olds were unable to find their toy if they only observed the person who had hidden it on a screen: Very young children, aged just 6 or 10 months, can indeed draw age-appropriate conclusions from what they have watched on a screen. Only then do they begin to no longer associate reality with what they have seen on the screen.

This seems paradoxical, and the explanation is fascinating: Children older than 1 year have learned in the meantime that what they see on a screen does not always correspond to reality: Cars cannot fly! There are no talking rubber balls! They now overgeneralize this knowledge — and no longer consider anything they only see on video to be true.

They only start to differentiate at the age of 3 that some of it is fantasy, but some is also a reflection of reality. Proof of this explanation was provided by a clever variation of the same experiment: 2-year-olds were again shown on a screen how someone was hiding a toy. This time, however, they were made to believe that they were observing the process through a real window. Afterward, they were perfectly capable of finding the toy.

*Originally published Jan. 1, 2025, this article was updated Jan. 10, 2024 with news about governments setting regulations, and new enriched media.