Chapter 2 What Children Need to Do in Childhood

Chapter 2

What Children Need to Do in Childhood

Imagine that you fell into a deep sleep on June 28, 2007—the day before the iPhone was released. Like Rip Van Winkle, the protagonist in an 1819 story by Washington Irving, you wake up 10 years later and look around. The physical world looks largely the same to you, but people are behaving strangely. Nearly all of them are clutching a small glass and metal rectangle, and anytime they stop moving, they assume a hunched position and stare at it. They do this the moment they sit down on a train, or enter an elevator, or stand in line. There is an eerie quiet in public places—even babies are silent, mesmerized by these rectangles. When you do hear people talking, they usually seem to be talking to themselves while wearing white earplugs.

I borrowed this thought experiment from my collaborator Tobias Rose-Stockwell and his wonderful book, Outrage Machine . Tobias uses this scenario to convey the transformation of the adult world. But the thought experiment applies even more powerfully to the world of late childhood and adolescence. In 2007, teens and many preteens were busy tapping out short texts on their phones, but texting in those days was cumbersome (press the 7 key four times to make an s ). Most of their texts were with one person at a time, and most used their basic phones to arrange ways to meet up in person. Nobody wanted to spend three consecutive hours texting. After the Great Rewiring, however, it became common for adolescents to spend most of their waking hours interacting with a smartphone, consuming content from strangers as well as friends, playing mobile games, watching videos, and posting on social media. By 2015, adolescents had a lot less time and motivation to get together in person. [1]

What happens to child and adolescent development when daily life—especially social life—gets radically rewired in this way? Might the new phone-based childhood alter the complex interplay of biological, psychological, and cultural development? Might it block kids from doing some of the things they need to do in order to turn into healthy, happy, competent, and successful adults? To answer these questions, we need to step back and look at five important features of human childhood.

Slow-Growth Childhood

Here’s a strange fact about human beings: Our kids grow fast, then slow, then fast. If you plot human growth curves against those of chimpanzees, you see that chimps grow at a steady pace until they reach sexual maturity, at which point they reproduce. [2] And why not? If evolution is all about maximizing surviving offspring, wouldn’t it be most adaptive to get to the reproduction part as fast as possible?

But human children wait. They grow rapidly for the first two years, slow down for the next seven to 10, and then undergo a rapid growth spurt during puberty before coming to a halt a few years later. Intriguingly, a child’s brain is already 90% of its full size by around age 5. [3] When Homo sapiens emerged, its children were big-brained small-bodied weaklings who ran around the forest practically begging predators to eat them. Why did we evolve to have this long and risky childhood?

The primary reason is that we evolved into cultural creatures between 1 million and 3 million years ago, roughly when our genus— Homo —emerged from earlier hominid species. Culture, which includes tool making, profoundly reshaped our evolutionary path. To give just one example: As we began using fire to cook our food, our jaws and guts reduced in size because cooked foods are so much easier to chew and digest. Our brains grew larger because the race for survival was won no longer by the fastest or strongest but by those most adept at learning. Our planet-changing trait was the ability to learn from each other and tap into the common pool of knowledge our ancestors and community had stored. Chimpanzees do very little of this. [4] Human childhood extended to give children time to learn.

The evolutionary race to learn the most made it maladaptive to reach puberty as fast as possible. Rather, there was a benefit to slowing things down. The brain doesn’t grow much in size during late childhood, but it is busy making new connections and losing old ones. As children seek out experiences and practice a range of skills, the neurons and synapses that are used infrequently fade away, while frequent connections solidify and quicken. In other words, evolution has provided humans an extended childhood that allows for a long period of learning the accumulated knowledge of one’s society—a kind of cultural apprenticeship, during adolescence, before one is seen and treated as an adult.

But evolution didn’t just lengthen childhood to make learning possible . It also installed three strong motivations to do things that make learning easy and likely : motivations for free play, attunement, and social learning. In the days of play-based childhood, the norm was that when school let out, children were out playing with each other, unsupervised, in ways that let them satisfy these motives. But in the transition to phone-based childhood, the designers of smartphones, video game systems, social media, and other addictive technologies lured kids into the virtual world, where they no longer got the full benefit of acting on these three motivations.

Free Play

Play is the work of childhood, [5] and all young mammals have the same job: Wire up your brain by playing vigorously and often. Hundreds of studies on young rats, monkeys, and humans show that young mammals want to play, need to play, and come out socially, cognitively, and emotionally impaired when they are deprived of play. [6]

In play, young mammals learn the skills they will need to be successful as adults, and they learn in the way that neurons like best: from repeated activity with feedback from success and failure in a low-stakes environment. Kittens pounce clumsily on a piece of yarn that triggers specialized circuits in their visual cortex that evolved to make them very interested in anything that looks like a mouse’s tail. Gradually, after many playful pounces, they’ll become skilled mouse killers. Human toddlers clumsily run around and climb up, over, or into anything they can, until they become skilled at moving around a complex natural environment. With those basic skills mastered, they move on to more advanced multiplayer predator-prey games, such as tag, hide-and-seek, and sharks and minnows. As they get older still, verbal play—as in gossip, teasing, and joking around—gives them an advanced course in nuance, nonverbal cues, and instantaneous relationship repair when something they said fails to produce the desired response. Over time, they develop the social skills necessary for life in a democratic society, including self-governance, joint decision making, and accepting the outcome when you lose a contest. Peter Gray, a developmental psychologist at Boston College and a leading play researcher, says that “play requires suppression of the drive to dominate and enables the formation of long-lasting cooperative bonds.” [7]

Gray defines “free play” as “activity that is freely chosen and directed by the participants and undertaken for its own sake, not consciously pursued to achieve ends that are distinct from the activity itself.” [8] Physical play, outdoors and with other children of mixed ages, is the healthiest, most natural, most beneficial sort of play. Play with some degree of physical risk is essential because it teaches children how to look after themselves and each other. [9] Children can only learn how to not get hurt in situations where it is possible to get hurt, such as wrestling with a friend, having a pretend sword fight, or negotiating with another child to enjoy a seesaw when a failed negotiation can lead to pain in one’s posterior, as well as embarrassment. When parents, teachers, and coaches get involved, it becomes less free, less playful, and less beneficial. Adults usually can’t stop themselves from directing and protecting.

A key feature of free play is that mistakes are generally not very costly . Everyone is clumsy at first, and everyone makes mistakes every day. Gradually, from trial and error, and with direct feedback from playmates, elementary school students become ready to take on the greater social complexity of middle school. It’s not homework that gets them ready, nor is it classes on handling their emotions. Such adult-led lessons may provide useful information, but information doesn’t do much to shape a developing brain. Play does. This relates to a key CBT insight: Experience, not information, is the key to emotional development. It is in unsupervised, child-led play where children best learn to tolerate bruises, handle their emotions, read other children’s emotions, take turns, resolve conflicts, and play fair. Children are intrinsically motivated to acquire these skills because they want to be included in the playgroup and keep the fun going.

This is why I have chosen the term “play-based childhood” as a central term in this book, to be contrasted with a “phone-based childhood.” A play-based childhood is one in which kids spend the majority of their free time playing with friends in the real world as I defined it in the introduction: embodied, synchronous, one-to-one or one-to-several, and in groups or communities where there is some cost to join or leave so people invest in relationships. This is how childhood was among hunter-gatherers, according to anthropological reports gathered by Gray, [10] which means that human childhood evolved during a long period in which brain development “expected” an enormous amount of free play. Of course, many children have had (and some still have) a work-based childhood. Work-based childhood was widespread during the Industrial Revolution, which is why, eventually, the 1959 United Nations Declaration of the Rights of the Child named play as a basic human right: “The child shall have full opportunity for play and recreation, which should be directed to the same purposes as education.” [11]

So you can see the problem when some adolescents start spending the majority of their waking hours on their phones (and other screens), sitting alone watching YouTube videos on auto-play or scrolling through bottomless feeds on Instagram, TikTok, and other apps. These interactions generally have the contrasting features of the virtual world: disembodied, asynchronous, one-to-many, and done either alone or in virtual groups that are easy to join and easy to leave.

Even if the content on these sites could somehow be filtered effectively to remove obviously harmful material, the addictive design of these platforms reduces the time available for face-to-face play in the real world. The reduction is so severe that we might refer to smartphones and tablets in the hands of children as experience blockers . Of course, a smartphone opens up worlds of new possible experiences, including video games (which are forms of play) and virtual long-distance friendships. But this happens at the cost of reducing the kinds of experiences humans evolved for and that they must have in abundance to become socially functional adults. It’s as if we gave our infants iPads loaded with movies about walking, but the movies were so engrossing that kids never put in the time or effort to practice walking.

The way young people use social media is generally not much like free play. In fact, posting and commenting on social media sites is the opposite of Gray’s definition. Life on the platforms forces young people to become their own brand managers, always thinking ahead about the social consequences of each photo, video, comment, and emoji they choose. Each action is not necessarily done “for its own sake.” Rather, every public action is, to some degree, strategic. It is, in Peter Gray’s phrase, “consciously pursued to achieve ends that are distinct from the activity itself.” Even for kids who never post anything, spending time on social media sites can still be harmful because of the chronic social comparison, the unachievable beauty standards, and the enormous amount of time taken away from everything else in life.

Surveys show that unstructured time with friends plummeted in the exact years that adolescents moved from basic phones to smartphones—the early 2010s. Figure 2.1 shows the percentage of U.S. students (combining 8th, 10th, and 12th graders) who said that they meet up with their friends “almost every day.”

For boys and for girls there was a slow decline in the 1990s and early 2000s, which I’ll discuss in the next chapter, followed by a faster decline in the 2010s. These accelerating declines are not just evidence of the Great Rewiring of Childhood, they are the Great Rewiring. Figure 2.1 shows us a generation moving away from the real world and into the virtual, thanks to the combination of smartphones, social media, multiplayer video games, and high-speed wireless internet.

Meet Up with Friends Daily

Figure 2.1. Percentage of U.S. students (8th, 10th, and 12th grade) who say that they meet up with their friends “almost every day” outside school. [12] (Source: Monitoring the Future. I explain how I use this important dataset in the endnotes.) [13]

Attunement

Human children are wired to connect, in part by tuning and synchronizing their movements and emotions with others. Even before they can control their arms and legs, they engage adults in games of turn taking and shared emotion. Children respond with the most heart-opening peals of laughter when adults—who are themselves built to respond to cuteness with caretaking [14] —do whatever they can to make the baby laugh. This creates a mutually reinforcing feedback loop. Infants in the first weeks of life have enough muscular control to mimic a few facial expressions, and the many rounds of mutual gazing and face making are important means of fostering attachment between parents and children. [15]

Smartphones can disrupt this essential face-to-face interaction. Pew Research has found that 17% of American parents report they are often distracted by their phone when spending time with their child, with another 52% saying they are sometimes distracted. [16] Although new technologies have long distracted parents from their children, smartphones are uniquely effective at interfering with the bond between parent and child. With notifications constantly pinging and interrupting, some parents attend to their smartphones more than to their children, even when they are playing together.

When toddlers begin to speak, vast new possibilities for attunement open up. The social connections with parents and other caretakers grow deeper. Turn taking and good timing are essential social skills, and they begin to develop in these simple interactions: How long should I wait before I make the next funny face or give the next rhyme in the rhyming game we’re developing? Each partner learns to read the other’s facial expressions and emotions to get the timing right. Developmental psychologists refer to these sorts of interactions as serve-and-return , conveying the idea that social interactions are often like a game of tennis or ping-pong: You take turns, it’s fun, there’s unpredictability, and timing is essential.

Attunement practice is as essential for social development as movement and exercise are for physical development. According to the National Institute for Play,

Attunement forms the foundations for later emotional self-regulation. Children who are deprived of this joyful, mutually trusting social experience often face emotional difficulties and exhibit erratic behavior in their later years. They can have difficulty forming healthy attachments as adolescents and as adults they may be less able to cope with unexpected challenges, regulate emotions, make sound decisions when risk is involved, or learn to deal effectively as they enter into more and more complex social interactions. [17]

As children get older, they go beyond turn taking to find joy in perfect synchrony, doing the same thing at the same time as their partner. Girls especially come to delight in singing songs together, jumping rope together, or playing rhyming and clapping games (such as pat-a-cake) in which high-speed hand motions are perfectly matched between the partners while high-speed nonsense songs are sung at the same time. Such games have no explicit goal or way to win. They are pleasurable because they use the ancient power of synchrony to create communion between unrelated people.

Anthropologists have long noted that collective rituals are universally human. The European explorers of the 16th and 17th centuries found that on every continent, communities performed rituals in which everyone moved together to drumming, chanting, or beat-heavy music. [18] Such rituals were widely said to renew trust and mend frayed social relations. The great sociologist émile Durkheim wrote about the “social electricity” generated by such rituals; [19] he thought rituals were essential for fostering a sense of communion and belonging.

Many experiments have now shown that synchronous movement has exactly these effects. In one study, small groups of college students were given headphones to wear and were asked to hold up a beer mug and sway along with the music that they heard. Half of the groups swayed in perfect harmony (because they were listening to the same music at the same time). Half were out of sync (because the music was delivered to their headphones that way). All groups then played a trust game in which a group makes the most money if they all cooperate across many rounds, but any one of them could earn more money by making the selfish choice on any single round. Groups that had moved in sync with each other trusted each other more, cooperated more, and made more money than those that had moved out of sync. [20]

Synchronous, face-to-face, physical interactions and rituals are a deep, ancient, and underappreciated part of human evolution. Adults enjoy them, and children need them for healthy development. Yet the major social media platforms draw children into endless hours of asynchronous interaction, which can become more like work than play. Most teens have accounts on multiple platforms, and those who use social media regularly spend two hours a day or more just on social media sites. [21] By 2014, nearly a third of teen girls were spending over 20 hours a week on social media sites. That’s half of a full-time job—creating content for the platform and consuming content created by others. That is time no longer available for interacting with friends in person. The work is often joyless, yet many feel compelled to do it, lest they “miss out” on something or be excluded. [22] Eventually, for many, it becomes a mindless habit, something they turn to dozens of times each day. Such social labor creates shallow connections because it is asynchronous and public, unlike a face-to-face conversation, or a private phone call or video call. And the interactions are disembodied; they use almost no muscles, other than in the swiping and typing fingers. We are physical, embodied creatures who evolved to use our hands, facial expressions, and head movements as communication channels, responding in real time to the similar movements of our partners. Gen Z is learning to pick emojis instead.

The loss of attunement is a second way that social media alters the course of childhood (while also fraying the social fabric). Given the vast amounts of time now invested in asynchronous interaction rather than getting together with friends, is it any wonder that so many teens found themselves lonely and starved for connection starting in the early 2010s?

Social Learning

Once our ancestors became cultural creatures, a new evolutionary pressure arose that rewarded the best learners. That doesn’t mean those who learn best in school from books and lectures. It means those children who best activated their innate desire to learn by copying and who then picked the right people to copy.

You might think that choosing role models is simple: Children should just copy their parents, right? But that turns out to be a losing strategy. There is no reason for a child to assume that her own parents happen to be the most skilled adults in the community, so why not search more widely? Also, children need to learn how to be a successful older child in their particular community, so children are particularly attentive to such models.

According to Rob Boyd and Pete Richerson, two of the leading scholars of gene-culture coevolution, [23] there are several “strategies” that won out over thousands of generations and became part of our evolved propensity for culture. The two that are most relevant for our discussion of social media are conformist bias and prestige bias .

The value of conformity is obvious: Doing whatever most people are doing is the safest strategy across a wide range of environments. It’s particularly valuable when you are a newcomer to an existing society: When in Rome, do as the Romans do. So when a child starts at a new school, she is particularly likely to do whatever it is that most children seem to be doing. We sometimes call this peer pressure, but it can be quite strong even when nobody is exerting pressure of any kind. It may be more accurate to call it conformity attraction. When American children move from elementary school to middle school (around age 11), they often discover, as my kids did, that most of their classmates have an Instagram account, which makes them want one too. And once on Instagram, they quickly learn how most of the people they follow use the platform, which makes them prone to using it that way too.

In a real-life social setting, it takes a while—often weeks—to get a good sense for what the most common behaviors are, because you need to observe multiple groups in multiple settings. But on a social media platform, a child can scroll through a thousand data points in one hour (at three seconds per post), each one accompanied by numerical evidence (likes) and comments that show whether the post was a success or a failure.

Social media platforms are therefore the most efficient conformity engines ever invented . They can shape an adolescent’s mental models of acceptable behavior in a matter of hours, whereas parents can struggle unsuccessfully for years to get their children to sit up straight or stop whining. Parents don’t get to use the power of conformity bias, so they are often no match for the socializing power of social media. [24]

But there’s an important learning strategy that goes beyond copying the majority: Detect prestige and then copy the prestigious. The major work on prestige bias was done by the evolutionary anthropologist Joe Henrich, [25] who was a student of Rob Boyd’s. Henrich noted that the social hierarchies of nonhuman primates are based on dominance—the ability, ultimately, to inflict violence on others. But humans have an alternative ranking system based on prestige , which is willingly conferred by people to those they see as having achieved excellence in a valued domain of activity, such as hunting or storytelling back in ancient times.

People can perceive excellence for themselves, but it’s more efficient to rely on the judgments of others. If most people say that Frank is the best archer in your community, and if you value archery, you’ll “look up” to Frank even if you’ve never seen him shoot an arrow. Henrich argues that the reason people become so deferential (starstruck) toward prestigious people is that they are motivated to get close to prestigious people in order to maximize their own learning and raise their own prestige by association. Prestigious people, in turn, will allow some supplicants to get close to them because having a retinue (a group of devoted attendants and followers) is a reliable signal to the community of their high standing in the prestige rankings.

Platform designers in Silicon Valley directly targeted this psychological system when they quantified and displayed the success of every post (likes, shares, retweets, comments) and every user, whose followers are literally called followers. Sean Parker, one of the early leaders of Facebook, admitted in a 2017 interview that the goal of Facebook’s and Instagram’s founders was to create “a social-validation feedback loop... exactly the kind of thing that a hacker like myself would come up with, because you’re exploiting a vulnerability in human psychology.” [26] But when the programmers quantified prestige based on the clicks of others, they hacked our psychology in ways that have been disastrous for young people’s social development. On social media platforms, the ancient link between excellence and prestige can be severed more easily than ever, so in following influencers who became famous for what they do in the virtual world, young people are often learning ways of talking, behaving, and emoting that may backfire in an office, family, or other real-world setting.

The rise of mass media in the 20th century initiated this decoupling of excellence and prestige. The phrase “famous for being famous” first became popular in the 1960s when it became possible for an ordinary person to rise in the public’s consciousness not for having done anything important but simply for having been seen by millions on TV and then being talked about over a few news cycles. [27] The phrase was later applied to the socialite and model Paris Hilton in the early 2000s, although her fame still depended on coverage by the mainstream and tabloid press. It was one of Paris Hilton’s closet organizers—Kim Kardashian—who redefined the phrase for the social media age. Kardashian pioneered a new path to high prestige that began with a sex tape that went public on the internet, which led to a reality TV show ( Keeping Up with the Kardashians ) that introduced her entire family to the public. In 2023, Kim had 364 million followers on Instagram, and her sister Kylie had 400 million.

Prestige-based social media platforms have hacked one of the most important learning mechanisms for adolescents, diverting their time, attention, and copying behavior away from a variety of role models with whom they could develop a mentoring relationship that would help them succeed in their real-world communities. Instead, beginning in the early 2010s, millions of Gen Z girls collectively aimed their most powerful learning systems at a small number of young women whose main excellence seems to be amassing followers to influence. At the same time, many Gen Z boys aimed their social learning systems at popular male influencers who offered them visions of masculinity that were also quite extreme and potentially inapplicable to their daily lives.

Expectant Brains and Sensitive Periods

Children express their desires to play, to attune with others, and to learn socially in different ways throughout the long cultural apprenticeship of their slow-growth childhood and their fast-growth puberty. Healthy brain development depends on getting the right experiences at the right age and in the right order.

In fact, brain development in mammals and birds is sometimes called “experience-expectant development” [28] because specific parts of the brain show increased malleability during periods of life when the animal is likely to have a specific kind of experience. The clearest example is the existence of “critical periods,” which are windows of time in which a young animal must learn something, or it will be hard if not impossible to learn later. Ducks, geese, and many other water- or ground-dwelling birds have an evolved learning mechanism called imprinting that tells the babies which adult they must follow. They will follow whatever mother-sized object moves in their field of vision a set number of hours after hatching. Many psychology textbooks show the photo in Figure 2.2 of the ethologist Konrad Lorenz being trailed by a line of goslings, who had imprinted on his boots because he had walked around the goslings during their critical period. Later research showed that it is possible for the young geese to learn a new attachment after the window has closed, yet even then the first thing they imprinted on retains a strong pull. [30] It has been stamped into their brains forever.

Figure 2.2. Baby geese who had imprinted on Konrad Lorenz’s boots. [29]

Humans have few true “critical periods” with hard time limits, but we do seem to have several “sensitive periods,” which are defined as periods in which it is very easy to learn something or acquire a skill, and outside of which it is more difficult. [31] Language learning is the clearest case. Children can learn multiple languages easily, but this ability drops off sharply during the first few years of puberty. [32] When a family moves to a new country, the kids who are 12 or younger will quickly become native speakers with no accent, while those who are 14 or older will probably be asked, for the rest of their lives, “Where are you from?”

There seems to be a similar sensitive period for cultural learning, which closes just a few years later—still during puberty. The Japanese anthropologist Yasuko Minoura studied the children of Japanese businessmen who had been transferred by their companies to live for a few years in California during the 1970s. [33] She wanted to know at what age America shaped their sense of self, their feelings, and their ways of interacting with friends, even after they returned to Japan. The answer, she found, was between ages 9 and 14 or 15. Those children who spent a few years in California during that sensitive period came to “feel American.” If they returned to Japan at 15 or later, they had a harder time readjusting, or coming to “feel Japanese.” Those who didn’t arrive in America until age 15 had no such problems, because they never came to feel American, and those who returned to Japan well before 14 were able to readjust, because they were still in their sensitive period and could relearn Japanese ways. Minoura noted that “during the sensitive period, a cultural meaning system for interpersonal relationships appears to become a salient part of self-identity to which they are emotionally attached.” [34]

So what happens to American children who generally get their first smartphone around the age of 11 and then get socialized into the cultures of Instagram, TikTok, video games, and online life for the rest of their teen years? The sequential introduction of age-appropriate experiences, tuned to sensitive periods and shared with same-age peers, had been the norm during the era of play-based childhood. But in a phone-based childhood, children are plunged into a whirlpool of adult content and experiences that arrive in no particular order. Identity, selfhood, emotions, and relationships will all be different if they develop online rather than in real life. What gets rewarded or punished, how deep friendships become, and above all what is desirable —all of these will be determined by the thousands of posts, comments, and ratings that the child sees each week. Any child who spends her sensitive period as a heavy user of social media will be shaped by the cultures of those sites. This may explain why Gen Z’s mental health outcomes are so much worse than those of the millennials: Gen Z was the first generation to go through puberty and the sensitive period for cultural learning on smartphones.

This hypothesis about puberty is not just my own speculation; a recent British study found direct evidence that puberty is indeed a sensitive period for harm from social media. A team led by the psychologist Amy Orben analyzed two large British data sets and found that the negative correlation between social media use and satisfaction with life was larger for those in the 10–15 age group than for those in the 16–21 age group, or any other age bracket. [35] They also examined a large longitudinal study to see if British teens who increased their social media use in one year would report worse mental health in the following year’s survey. For those in the peak years of puberty, which comes a bit earlier for girls, the answer was yes. For girls, the worst years for using social media were 11 to 13; for boys, it was 14 to 15. [36]

These results offer clear evidence that 13, which is the current (and unenforced) minimum age for opening an account on social media platforms, is too low. Thirteen-year-olds should not be scrolling through endless posts from influencers and other strangers when their brains are in such an open state, searching for exemplars to lock onto. They should be playing, synchronizing, and hanging out with their friends in person while leaving some room in the input streams to their eyes and ears for social learning from their parents, teachers, and other role models in their communities.

Putting this all together, we can now understand those sharp “elbows” in so many of the graphs in the previous chapter. Gen Z is the first generation to have gone through puberty hunched over smartphones and tablets, having fewer face-to-face conversations and shoulder-to-shoulder adventures with their friends. As childhood was rewired—especially between 2010 and 2015—adolescents became more anxious, depressed, and fragile. In this new phone-based childhood, free play, attunement, and local models for social learning are replaced by screen time, asynchronous interaction, and influencers chosen by algorithms. Children are, in a sense, deprived of childhood.

In Sum

Human childhood is very different from that of any other animal. Children’s brains grow to 90% of full size by age 5, but then take a long time to configure themselves. This slow-growth childhood is an adaptation for cultural learning. Childhood is an apprenticeship for learning the skills needed for success in one’s culture.

Free play is as essential for developing social skills, like conflict resolution, as it is for developing physical skills. But play-based childhoods were replaced by phone-based childhoods as children and adolescents moved their social lives and free time onto internet-connected devices.

Children learn through play to connect, synchronize, and take turns. They enjoy attunement and need enormous quantities of it. Attunement and synchrony bond pairs, groups, and whole communities. Social media, in contrast, is mostly asynchronous and performative. It inhibits attunement and leaves heavy users starving for social connection.

Children are born with two innate learning programs that help them to acquire their local culture. Conformist bias motivates them to copy whatever seems to be most common. Prestige bias motivates them to copy whoever seems to be the most accomplished and prestigious. Social media platforms, which are engineered for engagement, hijack social learning and drown out the culture of one’s family and local community while locking children’s eyes onto influencers of questionable value.

Social learning occurs throughout childhood, but there may be a sensitive period for cultural learning that spans roughly ages 9 to 15. Lessons learned and identities formed in these years are likely to imprint, or stick, more than at other ages. These are the crucial sensitive years of puberty. Unfortunately, they are also the years in which most adolescents in developed countries get their own phones and move their social lives online.