We Owe to the Adolescent Brain
Informational Text by Jeanne Miller
1 Polar bears can live above the Arctic Circle but they can't live at the Equator. Gorillas can live at the Equator but they can't live above the Arctic Circle. Humans, however, can live in the Arctic or they can live in the tropics. Why is our species so adaptable? We can thank our long period of adolescence
2 Most mammals have a period of adolescence. But as soon as they're able to reproduce, they begin bearing and caring for children. By contrast, humans, under the protection of their families, take many years to develop and grow into adulthood.
Brain Under Construction
3 Dr. Jay Giedd, professor of psychiatry1 at the University of California at San Diego, says, "Nothing is even close to
humans in terms of how long we're dependent on caregivers." He points out that in their early teens, Neanderthals2 already
had children of their own. Neanderthals died out, but our ancestors, Homo sapiens, thrived. A large part of that success comes from our brain's taking a long time to mature. This extended period of development lets us build exactly the brain we need in our circumstances. Giedd says, "All the brain's parts have their periods of rapid explosive growth and then rapid pruning back. You have overproduction-more connections than can possibly survive-and then they fight it out. The ones that are used and lead to positive outcomes stay, and those that aren't used, or are used and lead to bad outcomes, are eliminated."
(1) psychiatry: the branch of medicine that deals with the diagnosis, treatment, and prevention of mental
and emotional disorders.
(2) Neanderthals: an extinct human species or subspecies.
4 We lose "gray matter" and gain "white matter": myelin, which forms an insulating sheath around nerve fibers. "We get more and more myelin, which speeds up the communication between nerve cells, as we go through adolescence," says Giedd.
'We learn what we need to do and be good at and then the process streamlines that." But the price we pay is that, as myelin is laid down, flexibility diminishes. Adolescence is a kind of golden age when, as Giedd puts it, "You're asking your brain,
'What do I need to be good at? What do I need to do to make it in this world?' Every choice you make trains your brain."
5 This lets us adjust to our surroundings. Giedd points out,
"We all had ancestors that were good at adapting to change.
Neanderthals had brains that were about 13 percent bigger than ours and they lived in pretty tough conditions and harsh climates, but they didn't adapt."
Moving On from Childhood
6 Dr. B. J. Casey is a professor of psychology at Weill Cornell Medical College. Her focus on adolescent brains includes those of humans and mice. "There is evidence," she says, "that even adolescent rodents tend to hang out with same-aged peers and tend to have more fights with their parents." Sound familiar?
These behaviors- sensitivity to influence from peers, taking risks, and pulling away from parents- are hallmarks of human adolescence. They have their roots in the hunter-gatherer world of our early ancestors, where success meant surviving and reproducing.
7 Finding a mate and passing on your genes means leaving the comfort of your home. Casey says, "If you're getting all your needs met, why in the world would you leave? There needs to be some push-pull tension in evolution to get you to leave that home. Otherwise you'll deplete all the resources and it will be difficult to find a mate to partner with."
8 Going out into the world can involve risks, but the adolescent brain is wired for that. Giedd points out that "high risk equals high reward at times." And, compared to children or adults, teens are much more sensitive to rewards.
9 A study in Casey's lab demonstrated that fact when researchers put teenagers in a brain-scanning machine and asked them to complete a simple task. Successfully completing it earned them a lot of money. The resulting brain scans showed an exaggerated response in the reward center of the teens' brains, but only a moderate response in children and adults.
10 Sometimes the reward might be approval by their peers, who will be important to a teenager's future. In another study, Casey's group showed that, unlike children and adults, adolescents found smiling faces to be almost irresistible. She says, "When your peers are smiling it means they're accepting you."
11 Giedd says, "The peer group is the one that will help super you es. i bene uranates is manigating their
social world."
Stone Age Impulses in the Modern World
12 In hunter-gatherer societies, success in a risk-taking activity might result in a supply of food, in securing a mate, or in finding new territory. Of course, it can sometimes result in being killed by a predator. Taking certain risks can also pay off for modern teens. Giedd says, "As long as it's not lethal-as in the case of foolish risk-taking-it can lead to innovation and creativity."
13 The dangers today's teens face are different from those our early ancestors faced. It's a sad paradox that, relative to children, people in their late adolescence, who are generally the strongest and healthiest they'll ever be, face a 200 percent increase in the chance of dying. The main cause is accidents, with one-third of those being automobile crashes. Reckless driving and other dangerous behaviors put teenagers at risk, but young people also face threats to their health from the considerable stresses of growing up in the 21st century.
"Adolescents are dealing with a lot," Casey says, "but they should remember they have greater potential for change now than at any other time. There will be many opportunities for them to change behaviors that they don't want to engage in and to become what they want to be."
14 Giedd agrees. "The challenges adolescents present to their brains now will have effects for decades," he says. The potential for mastering new skills and honing their abilities is phenomenal. "We never lose it completely," Giedd says, "but it's never going to be as good as it is when we're adolescents."
1. According to Paragraph 1, why is the human species so adaptable? *
1 point
• We can thank our long period of adolescence for that.
Because polar bears can live above the Arctic Circle but they can't live at the Equator.
• Because gorillas can live at the Equator but they can't live above the Artic Circle.
• Humans can live in the Arctic or the tropics.
2. According to Paragraph 6, which behavior is NOT a typical hallmark or part of adolescence (the teen years)?
sensitivity to influence from peers
• taking risks
• pulling away from parents
• hunting and gathering
* 1 point
3. According to Paragraph 8, what is the adolescent brain wired for? *
• eating a lot
taking risks
• sleeping often
• arguing with mom
4. Giedd says, "As long as it's not lethal--as in the case of foolish risk-taking- * 1 point
-it can lead to innovation and creativity."
What does the word lethal mean in this sentence?
lively
deadly
foolishly
• slowly
5. Review Paragraph 14. Is the following statement true or false?
The main idea of Paragraph 14 is that adolescent brains have incredible potential for mastering new skills and honing their abilities.
* 1 point
• True
O False
1 answer
Here are the answers to your questions based on the provided text:
According to Paragraph 1, why is the human species so adaptable?
Answer: We can thank our long period of adolescence for that.
According to Paragraph 6, which behavior is NOT a typical hallmark or part of adolescence (the teen years)?
Answer: hunting and gathering
According to Paragraph 8, what is the adolescent brain wired for?
Answer: taking risks
What does the word lethal mean in this sentence?
Answer: deadly
Is the following statement true or false? The main idea of Paragraph 14 is that adolescent brains have incredible potential for mastering new skills and honing their abilities.
