Chapter 4 Puberty and the Blocked Transition to Adulthood

Chapter 4

Puberty and the Blocked Transition to Adulthood

From The Ugly Duckling to The Very Hungry Caterpillar, we reach for stories about animal metamorphosis to capture the emotions we feel as we watch our children grow and change. For humans, the change in bodies is not nearly as dramatic as it is for butterflies, yet the change in minds is every bit as extraordinary. But while caterpillars will turn into butterflies with little input from the outside world, the human transition from child to adult depends in part on getting the right kinds of experiences at the right time to guide the rapid rewiring of the adolescent brain.

Puberty, Plasticity, and Vulnerability

As I noted in chapter 2, the human brain reaches 90% of its adult size by age 5, and it has far more neurons and synapses at that moment than it will have in its adult form. Subsequent brain development, therefore, is not about overall growth but about the selective pruning of neurons and synapses, leaving only the ones that have been frequently used. Brain researchers say, “Neurons that fire together, wire together,” [1] meaning that activities that repeatedly activate a constellation of neurons cause those neurons to connect more closely. If a child goes through puberty doing a lot of archery, or painting, or video games, or social media, those activities will cause lasting structural changes in the brain, especially if they are rewarding. This is how cultural experience changes the brain, producing a young adult who feels American instead of Japanese, or who is habitually in discover mode as opposed to defend mode.

A second kind of brain change that occurs during childhood is called myelination, which refers to the coating of the axons of neurons with an insulating sheath of a fatty material, which makes transmission faster across the long-distance connections in those constellations of neurons. These slow processes of pruning and myelination are related to the great trade-off of human brain development: The young child’s brain has enormous potential (it can develop in many ways) but lower ability (it doesn’t do most things as well as an adult brain). However, as pruning and myelination proceed, the child’s brain becomes more efficient as it locks down into its adult configuration. This lockdown process happens in different parts of the brain at different times, and each lockdown is potentially the end of a sensitive period. It’s like cement hardening: If you try to draw your name in very wet cement, it will disappear quickly. If you wait until the cement is dry, you’ll leave no mark. But if you can catch it while it’s in the transition between wet and dry, your name will last forever. [2]

Because pruning and myelination speed up at the start of puberty, changes in children’s experiences during those years can have large and lasting effects. [3] In his textbook on adolescence, the developmental psychologist Laurence Steinberg notes that adolescence is not necessarily an especially stressful time. Rather, it is a time when the brain is more vulnerable to the effects of sustained stressors, which can tilt the adolescent into mental disorders such as generalized anxiety disorder, depression, eating disorders, and substance abuse. Steinberg adds,

Heightened susceptibility to stress in adolescence is a specific example of the fact that puberty makes the brain more malleable, or “plastic.” This makes adolescence both a time of risk (because the brain’s plasticity increases the chances that exposure to a stressful experience will cause harm) but also a window of opportunity for advancing adolescents’ health and well-being (because the same brain plasticity makes adolescence a time when interventions to improve mental health may be more effective). [4]

Puberty is therefore a period when we should be particularly concerned about what our children are experiencing . Physical conditions, including nutrition, sleep, and exercise, matter throughout all of childhood and adolescence. But because there is a sensitive period for cultural learning, and because it coincides with the accelerated rewiring of the brain that begins at the start of puberty, those first few years of puberty deserve special attention.

Experience Blockers: Safetyism and Smartphones

Unlike carnivores, which evolved to get nearly all the nutrients they need by eating the flesh of other animals, humans are omnivores. We need to consume a wide variety of foods to get all the necessary vitamins, minerals, and phytochemicals. A child who eats only white foods (pasta, potatoes, chicken) will be nutrient deficient and at heightened risk of diseases such as scurvy (caused by a severe vitamin C deficiency).

Similarly, humans are socially and culturally adaptable creatures who need a wide variety of social experiences to develop into flexible and socially skilled adults. Because children are antifragile, it is essential that those experiences involve some fear, conflict, and exclusion (though not too much). Safetyism is an experience blocker. It prevents children from getting the quantity and variety of real-world experiences and challenges that they need.

How much stress and challenge does a child need in order to grow? Steinberg notes that “stressful experiences” are “ones that could cause harm.” I wrote to him to ask if he agrees that children are antifragile and need exposure to short-term stressors—such as being excluded from a playgroup on one day—in order to develop resilience and emotional strength. He agreed that children are antifragile, and he added two qualifications to his statement about stressful experiences.

First, he noted that “chronic stress,” meaning stress that lasts for days, weeks, or even years, is much worse than “acute stress,” which refers to stress that comes on quickly but does not last long, such as an ordinary playground conflict. “Under chronic stress, it is much harder to adapt, recover, and get stronger from the challenge,” he wrote. His second qualification was that “there is an inverted U-shaped pattern in the relationship between stress and well-being. A little stress is beneficial to development, but a lot of stress, acute or chronic, is detrimental.”

Americans, Brits, and Canadians, unfortunately, tried to remove stressors and rough spots from children’s lives beginning in the 1980s. Many parents and schools banned activities that they perceived as having any risk, not just of physical injury, but of emotional pain as well. Safetyism requires banning most independent activity during childhood, especially outdoor activities (such as playing touch football without an adult referee) because such activities could lead to bruised bodies and bruised feelings.

Safetyism was imposed on the millennials beginning slowly in the 1980s and then more quickly in the 1990s. [5] The rapid deterioration of mental health, however, did not begin until the early 2010s and was concentrated in Gen Z, not among millennials. [6] It was not until the addition of the second experience blocker—the smartphone—that rates began to rise.

Of course, using a smartphone is an experience. It is a portal to the infinite knowledge of Wikipedia, YouTube, and now ChatGPT. It connects young people to special-interest communities for everything from baking and books to extreme politics and anorexia. A smartphone makes it effortless for adolescents to stay in touch with dozens of people throughout the day and to join others in praising or shaming people.

In fact, smartphones and other digital devices bring so many interesting experiences to children and adolescents that they cause a serious problem: They reduce interest in all non-screen-based forms of experience . Smartphones are like the cuckoo bird, which lays its eggs in other birds’ nests. The cuckoo egg hatches before the others, and the cuckoo hatchling promptly pushes the other eggs out of the nest in order to commandeer all of the food brought by the unsuspecting mother. Similarly, when a smartphone, tablet, or video game console lands in a child’s life, it will push out most other activities, at least partially. The child will spend many hours each day sitting enthralled and motionless (except for one finger) while ignoring everything beyond the screen. (Of course, the same might be true of the parents as well, as the family sits “alone together.”)

Are screen-based experiences less valuable than real-life flesh-and-blood experiences? When we’re talking about children whose brains evolved to expect certain kinds of experiences at certain ages, yes. A resounding yes. Communicating by text supplemented by emojis is not going to develop the parts of the brain that are “expecting” to get tuned up during conversations supplemented by facial expressions, changing vocal tones, direct eye contact, and body language. We can’t expect children and adolescents to develop adult-level real-world social skills when their social interactions are largely happening in the virtual world. [7] Synchronous video conversations are closer to real-life interactions but still lack the embodied experience.

If we want children to have a healthy pathway through puberty, we must first take them off experience blockers so that they can accumulate the wide range of experiences they need, including the real-world stressors their antifragile minds require to wire up properly. Then we should give children a clear pathway to adulthood with challenges, milestones, and a growing set of freedoms and responsibilities along the way.

Rites of Passage

On lists of human universals, [8] and on syllabi for introductory anthropology courses, you’ll usually find rites of passage. This is because communities require rituals to signify shifts in people’s status. It’s the community’s responsibility to conduct these rites, which commonly surround life events like birth (to welcome a new member and a new mother), marriage (to publicly declare a new social unit), and death (to acknowledge the departure of a member and the grieving of close kin). Most societies also have formal rites of passage around the time of puberty.

Despite the enormous variation in human cultures and gender roles, there is a common structure to puberty rites because they are all trying to do the same thing: Transform a girl into a woman or a boy into a man who has the knowledge, skills, virtues, and social standing to be an effective member of the community, soon to be ready for marriage and parenthood. In 1909, the Dutch-French ethnographer Arnold van Gennep noted that rites of passage around the world take the child through the same three phases. First, there is a separation phase in which young adolescents are removed from their parents and their childhood habits. Then there is a transition phase, led by adults other than the parents who guide the adolescent through challenges and sometimes ordeals. Finally, there is a reincorporation phase that is usually a joyous celebration by the community (including the parents), welcoming the adolescent as a new member of adult society, even though he or she will often receive years of further instruction and support.

Rites of passage for adolescents always reflect the structure and values of the adult society. Because all societies were highly gendered until recently, rites of passage have usually been different for girls and boys.

Rites for girls usually started soon after they had their first period, and the rites were often designed to prepare them for fertility and motherhood. Among Native Americans, for example, the Apache in Arizona still practice the “sunrise dance” after a girl’s first period. The initiate is guided by an older woman (a sponsoring godmother chosen by the family for this honor) to build a temporary hut for herself, at some distance from the main campsite. These preparations are the separation phase, and they include bathing, hair washing, and the donning of new clothing, all of which emphasize purification and separation from all traces of childhood. [9]

The transition phase involves four days of highly prescribed dancing to rhythmic drumming and chanting from the older women. These dramatic ritual enactments are infused with a sense of sacredness. With the transition phase complete, the girl is welcomed joyously into womanhood, with feasting and exchanges of gifts between her family and others. She is reincorporated into her village and household, but now with new roles, responsibilities, and knowledge.

In traditional societies, the rites for turning a boy into a man are different from the rites for turning a girl into a woman. Because the visible signs of puberty are less obvious, the timing is more flexible. In many societies, boys are initiated as a group—all the boys around a certain age, who will become tightly bonded to each other by their shared ordeal. In societies that experienced frequent armed conflict with neighboring groups, a warrior ethos usually developed among men, and the transition phase often included a requirement to undergo physical pain, including body piercings or circumcision, to test and then publicly validate one’s manhood. In many Indigenous North American societies, such as the Blackfoot in the Great Plains, the transition phase involved a vision quest in which the boy had to go out alone to a sacred site, chosen by the elders, where he fasted for four days while praying to the spirits for a vision or revelation of his purpose in life and the role he was to play in his community. [10]

Societies that were not preparing boys for war had very different kinds of rites for boys. In all Jewish communities, boys become subject to the laws of the Torah at the age of 13, and among their main duties as Jewish men, traditionally, was the study of the Torah. The Jewish rite of passage—the Bar Mitzvah—therefore involves a long period of instruction by a rabbi or scholar (not the father), followed by the big day when the boy takes the place of the rabbi in Saturday Shabbat services and reads the weekly Torah and haftorah portions in Hebrew. [11] In some Jewish communities, the boy then also delivers a commentary on what he has read. It is a challenging public performance for a boy who usually still looks like a child.

In Judaism, girls become subject to the commandments at the age of 12, which is likely an ancient recognition that girls enter puberty a year or two before boys. All but the most tradition-oriented congregations perform a ceremony for girls identical to the Bar Mitzvah called a Bat Mitzvah (which means “daughter of the commandment”; “bar” means son). Just because rites of passage always used to be gendered does not mean that they must be gendered today.

The fact that most societies used to have such rites suggests to me that our extremely new secular societies may be losing something important as we abandon public and communally marked rites of passage. A human child doesn’t morph into a culturally functional adult solely through biological maturation. Children benefit from role models (for cultural learning), challenges (to stimulate antifragility), public recognition of each new status (to change their social identity), and mentors who are not their parents as they mature into competent, flourishing adults. Evidence for the idea that children need rites of passage comes from the many cases where adolescents spontaneously construct initiation rites that are not supported by adults in the broader culture. In fact, anthropologists say that such rites come about precisely because of a society’s “failure to provide meaningful adolescent rites of passage ceremonies.” [12]

Such constructions are perhaps most vivid among groups of boys, especially when those boys must bond together to be more effective in competing with other groups of boys. Think of the initiation rites that young men develop for entry into a college fraternity, secret society, or street gang. [13] When boys and young men have the freedom to create their own rituals, it often looks as though at least one of them took that intro to anthropology class. They spontaneously create rituals of separation, transition, and incorporation (into peer groups) that we outsiders lump together as “hazing.” But because boys and young men construct these rites with little or no guidance from elders, the rituals can become cruel and dangerous. The resulting culture can also be dangerous for women when these young men try to demonstrate their manhood to their brothers in ways that exploit or humiliate women.

Girls construct rites of passage too, as when a college sorority inducts new members. These rites tend not to include as much physical pain as is demanded by boys, but there is often psychological pain related to beauty and sexuality. Initiates describe being rated, compared, and shamed for their physical features. [14]

Despite the pain and humiliation required for entry, many young people are willing to participate in these rites for the opportunity to join a binding social group and to transition away from childhood’s parental dependency and into peer-oriented young adulthood. This suggests that there may be a deep need among many adolescents for belonging and for the rites and rituals that create and express that belonging. Can we use that knowledge to improve adolescents’ transitions to adulthood?

Why Do We Block the Transition to Adulthood?

I used the metaphor that puberty is like the chrysalis stage of a butterfly’s life. But whereas the caterpillar hides away to emerge a few weeks later as a butterfly, the human child must undergo the transition in public over several years. Historically, there were plenty of adults, norms, and rituals to help the child along. But since the early 20th century, scholars have noted the disappearance of adolescent rites of passage across modern industrial societies. Such rites are now mostly confined to religious traditions, such as the Bar and Bat Mitzvah for Jews, the quinceanera celebration of a girl’s 15th birthday among Catholic Latin Americans, and confirmation ceremonies for teens in many Christian denominations. These remaining rites are likely to be less transformative than they once were as religious communities become less central to children’s lives in recent decades. [15]

Even without formal initiation rites, modern secular societies retained a few developmental milestones until quite recently. Those of us who grew up in the analog world of 20th-century America can remember a time when there were three nationally recognized age transitions that granted greater freedom and called for greater maturity:

At 13 you were thought to be mature enough to go to a movie theater without a parent because most of the movies you wanted to see were rated PG-13.

At 16 you could begin to drive (in most states). Cars were quasi-sacred objects for American teens, so this was a major birthday after which a new world of independent experience opened up for you. You had to learn to drive responsibly in the eyes of the state and of your parents or you’d lose this privilege.

At 18 you were considered an adult. You could legally enter a bar or buy alcohol in a liquor store. [16] You could buy cigarettes in most states (although that varied). You could vote, and if you were male, you had to register for potential military service. Also, high school graduation occurs around age 18, and that was the end of formal education for many people. After high school, graduates were expected to get a job or head off to college. In either case, there would be a major break with childhood and a big step toward adulthood.

In the real world, it often matters how old you are. But as life moved online, it mattered less and less. The mass movement from real world to virtual world started with the rise of fearful parenting and the gradual loss of play-based childhood. As overprotection and safetyism intensified in the 1990s, young people began engaging less in some of the major activities traditionally associated with teen development, activities that often required a car and permission to be out of the house, unsupervised.

Figure 4.1 shows the percentage of U.S. high school seniors (roughly age 18) who had gotten a driver’s license, and who had ever drunk alcohol, worked for pay, or had sexual intercourse. As you can see, the downturn in these activities did not start in the early 2010s; it started back in the 1990s and early 2000s.

Teens Engaging in Adult Activities

Figure 4.1. The percentage of U.S. high school seniors who have engaged in four adult activities has been declining since the 1990s or early 2000s, prior to the Great Rewiring of 2010 to 2015. (Source: Monitoring the Future and CDC Youth Risk Behavior Survey.) [17]

At the same time that adults were reducing young people’s access to the real world, the virtual world was becoming more accessible and more enticing. In the 1990s, millennial adolescents started spending more time on home computers connected to the internet. Computers became portable (laptops) and faster (higher connection speeds). But in the new virtual world, it almost never mattered how old you were. As soon as children could use a web browser, they had virtually unlimited access to everything on the web. And once teens moved from basic phones to smartphones, in the early 2010s, they could experience everything all day long. There is no equivalent to movie ratings such as PG-13, R, and X in the online world. Social media platforms such as Instagram, Snapchat, and TikTok don’t enforce their minimum age of 13. [18] Children are free to do as they please, and to play video games and exchange messages and photographs with unknown adults. Pornography sites also welcome children, as long as they click a box to say that they are 18 or older. Porn sites will show them how to have anal sex long before they’ve had their first kiss.

Once a child gets online, there is never a threshold age at which she is granted more autonomy or more rights. On the internet, everyone is the same age, which is no particular age. This is a major reason why a phone-based adolescence is badly mismatched with the needs of adolescents.

In short, adults are doing a variety of things to Gen Z, often with good intentions, that prevent adolescents from experiencing a widely shared and socially validated progression from childhood dependency to adult independence. We interfered with their growth in the 1980s and 1990s when we blocked them from risky play and ramped up adult supervision and monitoring. We gave them unfettered access to the internet instead, removing all age thresholds that used to mark the path to adulthood. A few years later, we gave their younger siblings smartphones in middle school. Once we had a new generation hooked on smartphones (and other screens) before the start of puberty, there was little space left in the stream of information entering their eyes and ears for guidance from mentors in their real-world communities during puberty. There was just an infinite river of digital experience, customized for each child to maximize clicks and ad revenue, to be consumed alone in his or her room. It all got worse during the COVID pandemic years of “social distancing” and online everything.

But it doesn’t have to be this way.

Building a Ladder from Childhood to Adulthood

A country that is large, secular, and diverse by race, religion, and politics may not be able to construct shared rites of passage that are full of moral guidance, like the Apache sunrise ceremony. Yet despite our differences, we all want our children to become socially competent and mentally healthy adults who are able to manage their own affairs, earn a living, and form stable romantic bonds. If we can agree on that much, then might we be able to agree on norms that lay out some of the steps on that path? Importantly, these would mostly be norms, not laws, which any parent could choose to follow or ignore. Engaging in commonly held norm-based rituals and sharing milestones might be more effective than practices that each family invents for itself.

As an initial proposal, to start a conversation, I suggest that we focus on even-year birthdays from ages 6 to 18. We might make a big deal out of those birthdays by linking them to new freedoms, new responsibilities, and significant increases in allowance. We want children to feel that they are climbing a ladder with clearly labeled rungs, rather than just having an annual party with games, cake, and presents. It might look something like this:

Age 6: The age of family responsibility. Children are formally recognized as important contributors to the household, not just as dependents. As an example, they can be given a small list of chores and a small weekly allowance that is contingent upon their performance of those chores. [19]

Age 8: The age of local freedom. Children gain the freedom to play and hang out in groups without adult supervision. They should show that they can take care of each other, and they begin running local errands, if there are stores within a short walk or bike ride. They should not be given adult cell phones, but they could be given a phone or watch designed for children that would allow them to call or text a small number of people (such as their parents and siblings).

Age 10: The age of roaming. Preteens gain the freedom to roam more widely, perhaps equivalent to what their parents were allowed to do at the age of 8 or 9. They should show good judgment and do more to help their families. Consistent with their increased mobility and responsibility, a flip phone or other basic phone with few apps and no internet access might be given as a birthday present. They should not have most afternoons filled with adult-led “enrichment” activities; they need time to hang out with friends in person.

Age 12: The age of apprenticeship. At 12, which is around the age that many societies begin rites of initiation, adolescents should begin finding more adult mentors and role models beyond their parents. Adolescents should be encouraged to start earning their own money by doing chores for neighbors or relatives, such as raking leaves or working as a mother’s helper for a neighbor with an infant or toddler. They might be encouraged to spend more time with trusted relatives, without their parents present.

Age 14: The beginning of high school. The 14th birthday comes around the time that high school begins, and this is a major transition during which independence increases along with academic pressure, time pressure, and social pressure. Activities such as working for pay and joining an athletic team are good ways to discover that hard work leads to tangible and pleasurable rewards. The beginning of high school would be a reasonable target for a national norm (not a law) about the minimum age at which teens get their first smartphone. [20]

Age 16: The beginning of internet adulthood. This should be a big year of independence, conditional on showing a history of responsibility and growth since the previous step. The U.S. Congress should undo the mistake it made in 1998 when it made 13 the age at which children can sign contracts with corporations to open accounts and give away their data without their parents’ knowledge or consent. I believe the age should be raised to 16 and enforced. The 16th birthday would become a major milestone at which we say to teens, “You can now get a driver’s license, and you can now sign certain kinds of contracts without any legal requirement for parental consent. You can now open social media accounts as well.” (There are good arguments for waiting until 18, but I think 16 would be the right minimum age to be established by law.)

Age 18: The beginning of legal adulthood. This birthday would retain all of its legal significance including the beginning of voting, eligibility for military service, and the ability to sign contracts and make life decisions. Because this birthday falls near high school graduation in the United States, it should be treated in van Gennep’s terms as both a separation from childhood and the beginning of a transition period into the next phase of life.

Age 21: Full legal adulthood. This birthday is the last one with any legal significance in the United States and many countries. At this age one can buy alcohol and cigarettes. One can enter casinos and sign up for internet sports gambling, The person is now a full adult in the eyes of the law.

These are my suggestions for a path to adulthood in a modern secular society. Your environment may be different, and your child may need to move along a different path at a different speed. But we should not let our variations force us to remove all common milestones and leave children to just wander around without any shared standards or age-graded increases in freedoms and responsibilities. Children do not turn into fully functioning adults on their own. Let’s lay out some steps they can take that will help them to get there.

In Sum

Early puberty is a period of rapid brain rewiring, second only to the first few years of life. Neural pruning and myelination are occurring at a very rapid rate, guided by the adolescent’s experiences. We should be concerned about those experiences and not let strangers and algorithms choose them.

Safetyism is an experience blocker. When we make children’s safety a quasi-sacred value and don’t allow them to take any risks, we block them from overcoming anxiety, learning to manage risk, and learning to be self-governing, all of which are essential for becoming healthy and competent adults.

Smartphones are a second kind of experience blocker. Once they enter a child’s life, they push out or reduce all other forms of non-phone-based experience, which is the kind that their experience-expectant brains most need.

Rites of passage are the curated sets of experiences that human societies arrange to help adolescents make the transition to adulthood. Van Gennep noted that these rites usually have a separation phase, a transformation phase, and a reincorporation phase.

Western societies have eliminated many rites of passage, and the digital world that opened up in the 1990s eventually buried most milestones and obscured the path to adulthood. Once children began spending much or most of their time online, the inputs to their developing brains became undifferentiated torrents of stimuli with no age grading or age restrictions.

A society that is large, diverse, and secular (such as the United States or the U.K.) might still agree to a set of milestones that mark stepwise increases in freedoms and responsibilities.

This concludes part 2, which presented the lead-up to the Great Rewiring of Childhood that occurred between 2010 and 2015. I explained why human childhood has the unique features that it has and why a play-based childhood is so well matched to those features. I showed evidence that the play-based childhood was in retreat well before the arrival of smartphones. Now we’re ready to move on to part 3, in which I’ll tell the story of what happened when adolescents transitioned from basic phones to smartphones, which began in the late 2000s and accelerated in the early 2010s. I’ll present the evidence that the new phone-based childhood that emerged in those years is bad for children and adolescents, and I’ll show that the harm goes far beyond increases in mental illness.