“When you’re younger, your mind is more open and you’re more creative,” says 13-year-old Leo De Leon. Adolescence is a period of rapid brain development, which scientists call “breathtaking”.
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“When you’re younger, your mind is more open and you’re more creative,” says 13-year-old Leo De Leon. Adolescence is a period of rapid brain development, which scientists call “breathtaking”.
Jon Hamilton/NPR
For parents of a teenager, the teenage years can be a difficult time. But for a brain specialist, it’s a marvel.
“I want people to understand that adolescence is not a disease, that adolescence is a wonderful period of development,” says Beatrice Lunaprofessor of psychiatry and pediatrics at the University of Pittsburgh.
This development is on display most afternoons at the Shaw Skatepark in Washington, DC. It’s a public site, filled with teenagers hanging out, taking risks, and learning new skills at a rapid pace.
“When you’re younger, your mind is more open and you’re more creative, and nothing matters,” says 13-year-old Leo De Leon. “So you really try anything.”
Leo has been skateboarding since he was 10 years old. But having the courage to try a skate park for the first time was “a bit scary”, he says. “I crashed a lot when I started. And I got hurt a lot.”
Leo has also improved – quickly. And when he mastered a trick, he pushed himself to learn a new one, despite the risks.
“I was trying to ollie something, then I cut it and my board came up and it hit me in the mouth,” he says, “so now I have this scar.”
Leo also broke his arm and his elbows are a mess. But the payoff is that he can now do things like jump the flight of five steps to the other side of the park.
“I kick this one,” he said. “He’s on my Instagram.
Leo’s persistence and tolerance for scars, broken bones and bruises paid off. As soon as he mastered a trick, he pushed himself to learn a new one.
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Leo’s persistence and tolerance for scars, broken bones and bruises paid off. As soon as he mastered a trick, he pushed himself to learn a new one.
Jon Hamilton/NPR
In search of new experiences
Leo’s rapid progression from scared novice to accomplished skater shows the strengths of a teenage brain.
“He’s an amazing brain,” Luna says. “He’s just perfect for what he needs to do. And what he needs to do is gain experience.”
A child’s brain goes through two critical periods of very rapid change.
The first occurs around age two, when most toddlers are busy walking, talking, climbing and falling. The second critical period begins around puberty.
“Adolescence is a time when the brain says, ‘Okay, you’ve had a lot of time now, we need to start making decisions,'” Luna says.
Decisions such as which connections to delete.
“You were born with an excess of synaptic connections,” Luna says. “And from experience, you keep what you use and you lose what you don’t use.”
It is a process known as synaptic pruning. And his impending arrival may be one of the reasons a teenage brain seeks out new experiences, even if it means risking a broken arm or a broken heart.
During this period, the brain also optimizes the wiring it decides to keep.
“The links that remain become myelinated,Luna says. “That means they’re insulated with fatty tissue, which not only speeds up neural transmission, but protects against any further changes.”
Sex differences in brain and behavior
Teenage brain changes tend to start earlier in girls than in boys. And around this time, men and women also begin to react differently to certain experiences, such as stress.
This was one of the conclusions of a adolescent research analysis asked to perform tasks like solving an impossible math problem or giving a talk to a group of strangers.
“The men’s blood pressure was higher than the women’s,” says Luna. But when participants were asked about the experience later, the men said “oh, that was good”, while the women described it as “extremely stressful”.
Luna says this suggests there are gender differences in certain brain circuits. But it’s unclear whether these differences are the result of genetic, hormonal, or social and cultural influences, she says.
Either way, gender differences are just a small part of the big changes that go through the brain during adolescence. And these changes continue throughout adolescence and beyond.
“A lot of times people think, oh, too late, they’re teenagers,” Luna says. “But no, because although it’s a time of vulnerabilities, it’s also a window of opportunity.”
Adolescence, chimpanzee style
Adolescence isn’t just for humans. It is also present in chimpanzees.
“There’s something really lovely about chimpanzees when they go through that teenage period,” says Alexandra Rosati, associate professor of sociology and anthropology at the University of Michigan. “They look a little lanky. They have these new big teeth in their mouths.”
And, of course, they experience puberty.
“They’re going through this physical change in the body and these same hormones are resculpting the brain, essentially, during this time,” Rosati says.
Part of this restructuring involves the willingness to take risks.
Rosati was part of a team that made a gaming experience with 40 chimpanzees of various ages in a sanctuary in the Republic of Congo.
The chimpanzees had a choice. They could opt for one sure thing: peanuts. Or they could choose a mysterious option which could be a boring cucumber or a delicious banana.
“The adolescent chimpanzees were more willing to make that bet,” says Rosati. “They were more likely to take this risky option and hopefully get the banana, whereas adults were more likely to play it safe.”
This suggests that both young humans and chimpanzees are predisposed to risky behaviors.
“The fact that we see these changes in risk taking in chimpanzees suggests that it follows something biological,” says Rosati. “It’s not something to do with human culture or how kids are exposed to media or anything.”
For both species, Rosati says, there’s a purpose to this kind of risk-taking. “This period of risk-taking in adolescence allows children to grow into adults who are learning to live independently,” she says.
Risky business and dopamine
So how does the brain of an adolescent chimpanzee or a human encourage risk taking? With dopamine, a natural chemical involved in memory, motivation and reward.
Teenage brains produce more dopamine and are more sensitive to the chemical than adult brains, says Adriana Galvanprofessor of psychology at the University of California at Los Angeles.
This means greater reward from positive experiences like eating a piece of chocolate or just hanging out with friends.
“It’s a feedback loop,” she says, “because then you start thinking, well, that was pretty good. I’m going to make that happen again.”
This amplified reward system also helps young brains learn faster by pushing boundaries and constantly asking, “What happens when I do this?” Galván says, “because that’s how we learn best.”
But big rewards and rapid learning can leave the teenage brain vulnerable to certain behaviors that are harmful rather than helpful.
“If the behavior is to use drugs, the brain says, ‘Oh, okay, that’s what I should pay attention to and dedicate my neurons and my pathways,'” says Galván. “So you reinforce that. And ultimately, that’s how the addiction happens.”
The vulnerability of the brain during adolescence is likely one of the reasons so many adult smokers pick up the habit in adolescence, Galván says.
During adolescence, though, the brain’s priorities change, she says. At first, he pays more attention to positive experiences than to painful ones. But then the balance begins to shift.
This seems to happen with Leo the skateboarder.
“I used to do a lot of stair sets,” he says. “I feel like I’m old now because I can’t really do them anymore because they hurt me.”
All of this suggests that Leo’s brain is developing exactly as it’s supposed to.
