Use of English B1+ Adolescence

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 … in part on getting the right kinds of experiences at the right time to guide the rapid rewiring of the adolescent brain.

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," meaning that activities that repeatedly activate a constellation of neurons … those neurons to connect more closely.

If a child goes through puberty … 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 … 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 … 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 my-elination 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 … forever.

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. 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 … stressors, which can tilt the adolescent into mental disorders such as generalized anxiety disorder, depression, eating disorders, and substance abuse.

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 … adolescents' health and well-being (because the same brain plasticity makes adolescence a time when interventions to improve mental health may be more effective).

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 … 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, miner-als, and phytochemicals. A child who eats only white foods (pasta, pota-toes, chicken) will be nutrient deficient and at … 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 … 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 … 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.