Deciphering the teen brain and behavior

New science finds developmental stage lasts into 20s — which explains some trying behavior

By Scott Hewitt, Columbian social issues & neighborhoods reporter

Published:

 

YOYO, you know? So GOMB! I'm LHHIMB!

You're only young once, that is, so get off my back! I'm laughing hella hard inside my brain!

Actually, there's much more than hysterical laughter and angry outbursts — and textspeak — happening in the brains of adolescents. Over the past decade, scientists have taken advantage of cutting-edge technology such as magnetic resonance imaging to peer deeply into the heads of young people.

What they have found is that long-accepted conventional wisdom about the developing human brain — that earliest training and conditioning are what matter most, because the game is up by age 3 or so — is not entirely true.

"We know from research that early childhood is a critical period," said Jane Lanigan, an associate professor of human development at Washington State University Vancouver. "What we've learned is that adolescence is a second critical period."

Parenting links

Jane Lanigan, associate professor of human development at Washington State University Vancouver, recommends a couple of websites for parents:

parenting247.org, posted by the University of Illinois

myparenthetical.com, free registration gets you many informative, snappy articles on parenting teens and tweens

Neuroplasticity keeps the brain learning

In a word, what we've learned recently about the developing brain is this: neuroplasticity. That's the brain's lifelong ability to learn new things and rewire itself.

It's not as easy when you're 70 as when you're 20. But it's not impossible, either. While the jury remains out on spendy brain-fitness programs, most scientists and medical professionals agree on the lifelong benefits of keeping your head working on enjoyable challenges, be it the daily Sudoku puzzle or those saxophone lessons you always wanted to try.

Here's a quick guide to what's going on between your ears during five essential stages of life.

In utero and infancy: The brain is building structure and forming connections. There are trillions of synapses in the newborn brain — twice as many as in the adult one — leading some to call it the most complex thing in the universe. Recent science has found that unborn and young children who experience traumatic stress — not to mention drugs and alcohol — may carry markers of it all their lives.

Years 1 to 6: The brain is like a fast-growing sponge, reaching 95 percent of its adult weight. Perception and reasoning, movement and emotions, planning and memory are all firing up, while the ancient, instinctive "lizard brain" is already on the job. Parents who nurture, stimulate and "chat up" their kids are building a firm lifelong foundation; parents who are overly negative or harsh are setting that foundation, too.

Years 7 to 22: The second stage of peak brain development is in early adolescence, making it another phase of high emotion and inconsistency. Hormones are coursing through the system while the prefrontal cortex, which controls impulses and makes reasoned decisions, is the last to mature. Teens should strive to think twice about taking risks; parents should keep lines of communication open and strive for a balance of understanding, patience and consistency.

"Adulthood": The brain is reaching the peak of its power, and with it your ability to communicate, undertake and resolve challenges and strike a mature balance between rational, emotional and intuitive behavior. But the brain regions that matured last are also the first to start declining, eventually leading to slower processing speeds and spottier memory. Experts advise "lifelong learning" as well as standard health practices like healthy eating and exercise.

65 and better: Science is still teasing out details of the aging brain. Memory may be declining and speed slowing, but continuing to challenge your brain will spur the growth of new brain cells. New research suggests that some of the aging brain's slowing may be caused by the huge amount of stuff that's stored in there — a lifelong accumulation.

SOURCES: National Institutes of Health, National Geographic, The New York Times, Public Broadcasting Service, SharpBrains

Until you're well into your 20s — and especially in your early- to midteen years, somewhere between 12 and 15 — that brain of yours remains a bustling construction, demolition and reconstruction site. Cells and connecting synapses are being grown, used and strengthened — or not used, pruned and replaced. Totally occupied by vast volumes of incoming information and sensation, and practicing up on bodily functions and feelings, the young brain's necessary skill at mature decision-making and top-down control develops much later — last, in fact. Meanwhile a region called the amygdala — the seat of fear, emotional reactions and fight-or-flight instincts — is fully functioning from day one.

For parents of not-so-young children, knowing all that can help ease a life passage that's fraught with conflict, risk, rapid changes, high emotion and little logic.

"The developmental phase and the dependency on parents goes well into the early 20s," Lanigan said. "Early childhood is critical, but I'm concerned about … the message that nothing matters from age 3 on. The research does not support that.

"It's a time of intense change," she said. "They can go in all different directions. It can be very inconsistent." Parents who respond with both understanding and consistency "are going to see better outcomes," she said.

Training time

Red light. What do you do?

Stop and wait, look around and be safe, of course. Everybody knows that. Unless, that is, they've got "incomplete frontal lobe development," Lanigan said.

The whole frontal lobe area, and in particular the prefrontal cortex that's right behind your eyes and forehead, is the brain's mature decision-maker — the part that considers: What if I just floor it and blast through the intersection? Even more broadly, what happens to the whole world if everybody starts blasting through intersections?

That kind of abstract, moral thinking — "I must follow the rules because they make sense for me, and also because all would be chaos if everybody stopped following rules" — doesn't come early to the human brain. It comes with time and training, and the physical development and thickening of the gray matter in that frontal lobe.

Before that, Lanigan said, your fledgling frontal lobe just can't compete with the excellent, early hardwiring of those emotion and quick-reaction areas. Result: Teenagers "aren't able to think of all the factors they should. At that age, they may have gotten away from being completely egocentric, but they're still feeling invincible," Lanigan said. "There's a lot going on in their decision-making, but the capacity to make really rational decisions is still limited."

And while the newest science has found that the brain remains a building site for years longer than previously thought, it also remains true that a brain that spends lots of critical training time — those mid-teen years — strengthening that sense of invincibility isn't likely to unlearn it. A teenager who repeats the thrill of blowing through a red light over and over again, lucking out and laughing each time, isn't building up wisdom and restraint in the prefrontal cortex.

Lanigan laughingly cited a study that presented adolescents and adults two options: jumping off the edge of the Grand Canyon with a 50 percent chance of survival — or not. Nobody took the chance, but adolescents generally took "several seconds longer" to decide that the whole proposition was a loser. Scans of their brains showed activity in lots of different places — not just the underdeveloped frontal cortex — as they considered the idea. "It shows that their way of thinking about things is different," Lanigan said.

According to the American Association of Child and Adolescent Psychiatry, adolescents are prone to impulsive or even risky behaviors, misreading or misinterpreting social cues and emotions, and getting into accidents and fights. They're less prone to (all together now, parents) thinking before acting.

None of which means your kid can't make good decisions or tell right from wrong, the AACAP points out, nor does it mean that appropriate consequences for behavior aren't, well, appropriate — in fact they are vital teaching tools that help train the brain, and the more consistent the better. But parents and teachers who soften their standards slightly with some understanding and patience for churning behind the scenes — between the ears, that is — are going to have an easier time of it. They'll probably earn their adolescent's appreciation too — if not immediately, then in the long run.

"Sixteen or so is a time when many parents just let go. Maybe they think they've done everything they can do," said Kathy Bobula, who teaches early childhood education and psychology at Clark College. "But your child still needs your support and guidance at 16. You need to keep at it."

Bomber pilots, football players

The things adolescents spend time doing, and loving to do, have a serious influence on their brains, and therefore their whole lives, as they age. That's why Bobula loves it when students get into volunteerism — and hates it when they bring cellphones to class. "Adolescents who get involved in service learning learn that that's normal and good. That's what's hooking up in the brain," she said. But adolescents "who play video games all day, who just satisfy their transient desires all day, well, that's what's hooking up in the brain. They sure get good at that," she laughed. "They develop great thumb control and eye-hand coordination and they'll probably grow up to be great bomber pilots.

"But that's at the expense of deeper thoughts and conversations, moral choices, relating to people," Bobula said.

It's also at the expense of deep, long-term focus, Bobula said. Science has found that people who do whatever they do with one eye always on their cellphone -- or TV, or whatever electronic distraction you choose — are not doing it very well. "There's a pretty strong body of research showing that we don't multitask effectively," Lanigan said. "You're not performing as efficiently as you like to think you are."

Drop that essay or project to check your messages or satisfy that irresistible craving for a video fix of a cute kitty. Think you have that same train of thought, the same level of concentration when you return to the task? No way, Bobula said.

It gets worse. Bobula pointed out all the head-injury research that's been done lately on football players and war veterans and flatly declared: "You damage that frontal lobe part, the part that does self-regulation of all types, you wind up a real jerk. You won't stop when the light turns red. You won't necessarily stop yourself in all sorts of situations where it's appropriate to stop."

Drugs and alcohol affect the growing teen brain differently and more dramatically than the adult brain. In an interview with the television show "Frontline," leading brain researcher Jay Giedd of the National Institute of Mental Health said it's a "particularly cruel irony of nature … that this time when the brain is most vulnerable is also the time when teens are most likely to experiment with drugs or alcohol." Giedd said, "It may not just be affecting their brains for that night or even for that weekend, but for the next 80 years of their life."

Strong foundation

Is anything more painful for a teenager than getting up in the morning (or afternoon)?

"The way schools and society are structured, adolescents don't get to follow their natural circadian rhythms," Lanigan said.

"The data is in. We're sending them to school sleep-deprived," said Bobula. "Why do we make our kids' lives fit the bus schedule? Why do schools make them work against, rather than with, their own bodies? Don't make them go to school so early."

That's these two teachers' advice for the American education system. Their advice for parents is equally common sense: establish closeness and communication early and often. Set reasonably strict levels of parental monitoring and kid responsibility -- what Lanigan calls "a traditional parenting style. That will give you a strong foundation to build upon." It means knowing what your teen is doing, and where, and with whom.

"Not necessarily directing what they're doing, but at least knowing," said Lanigan. "There's a pretty big block of research about parental monitoring. It definitely shows better outcomes for children whose parents do a high level of monitoring."

Bobula is totally into telling it like it is: "I'm such an advocate of informing adolescents what's going on in their heads. You will make some wrong decisions. You may find yourself acting weird. You may find your emotions so strong they're overwhelming. You may find high school horrible."

It's all a test of your parenting Zen. When does your kid need support and when independence? When do you lean in close and when do you pull back? "It varies by family. The parents are the best judges. They'll have an instinct for what's typical and what's more alarming for their child," Lanigan said.

"Typical teen development includes a phase when they're going to need to individuate. They often pull away," she said. "It can be very frightening for parents. But it's right on schedule."