The brain itself in the first 12 years of life, childhood, is basically like a sponge. It's going to soak in. Knowledge from the adult world. Just soak it in.
People thought that adolescence would be a period of just continuing to be like a sponge, only it becomes more sophisticated. But what shocked everyone was that around 12 years of age, about a year and a half earlier, for girls, and this is in the United States. Okay, so these studies at UCLA and National Institute of Mental Health that have been extensively studying the same individuals over the lifespan, these are all American kids, and we need to say that, because if we did this study in Papua New Guinea, you might feel like, find a completely different pattern. But these are American kids shaped by American culture, and that's what we can say about American adolescents.
And here's what we know, is that around 12, as an average, the brain starts to do something that shocked everyone. It starts to destroy itself in a process called pruning. Like in a garden when you have a big tree and you start pruning away the limbs, it starts to prune away stuff which no one thought would be happening.
Then, later on in adolescence, it takes those neurons that have remained in their connections, and it lays down a very important sheath that's been laid down earlier in life, but now it's laid down in gusto, called myelin, M-Y-E-L-I-N. Myelin allows the communication of this, what's called... called an action potential, the way neurons fire, to go 100 times faster. And the resting period between firings to be 30 times shorter.
So if you multiply the 30 times shorter refractory period and the 100 times faster speed, you get 3,000 times more efficient in how the nervous system is functioning when you've laid down myelin. So when you watch the Olympics and you say, oh my God, I could never do a flip like that, you're right. Because you have to do it.
haven't taken the time to lay down myelin and that's what skills are based on. So here's the idea. Adolescence is a period of remodeling of the brain.
What nature does to get this adolescent ready to leave home is start to remodel the brain instead of continuing the same childhood stuff. All these changes in the limbic functioning are happening, the way the brain and the limbic area are working together, and in the cortex there's something else that's happening we're going to review, but overall... You're basically going from being a generalist as a child to a specialist during adolescence.
That's what the carving down is all about. It says if I'm not doing that, it's a use it or lose it principle, then I don't need it. If I'm not playing music, I don't really need those music capacities anymore.
So for our son who's a musician, I mean he would not stop playing music at 12 and continued seven, eight hours a day and now it's just like another part of his body. And that's the way it works. You keep on doing something and you lay down myelin. And you keep those circuits during adolescence.
So what I say to the adolescent reading the brainstorm book is I say, if there's something you love and you want to keep those circuits, keep on doing it. So when kids are doing something over in video games over and over again, they're not out using their body for anything or not learning social skills, they're not doing all those things. It's not that they're going to lose it forever, though they could. It's that they're going to lose the huge potential that they have at the beginning of adolescence if they don't keep something going.
And let me tell you something. My hope is instead of a parent telling them this, if a nonfiction science book says this, then maybe they'll actually believe it and they can do it. The other thing that we can see is that there's another thing the brain does that we need to really understand.
How are you going to get this kid, now an adolescent, to go to what's unfamiliar, to go to what's uncertain, to go to what's potentially dangerous? What are you going to do if you're nature? Well, you're going to do two things.
There's a system that connects the brainstem, the limbic area, and the cortex. And that's called the dopamine reward system of the brain. It's vertically distributed.
And some studies suggest that... the following things happen to the dopamine reward system of the adolescent brain that no one knew about before, but that explains a huge amount about adolescents. The baseline levels of dopamine of an adolescent compared to a kid or an adult are lower. But the release amounts are higher.
And one of the major things that releases dopamine is novelty. New stuff stimulates dopamine release. So you can see how brilliant nature is because nature creates this system change in the reward circuitry. So it says, okay, I'm going to drop your dopamine. I'm going to raise your release levels.
So boom, what does a dropped dopamine level do? It makes you feel kind of bored. and UTSI with the same old same old which is why middle schools and high schools have got to change the way they approach the school experience because so many adolescents find it a complete waste of time which is so sad because there's an unbelievable resource there you're going to see.
Number two is you change the way the evaluative circuits work that work with the cortex and something has a really wacko name and I couldn't think of a better name so I just kept the wacko name. It's called hyper-rational thinking. And what hyper-rational thinking is, is basically the cortex is being influenced by the limbic area, which is going to focus on the positive aspect of a choice and minimize the risky, dangerous negative of a choice. So this is another myth.
A lot of adults think adolescents just don't know about dangers. They're very informed about dangers, they just don't care about them. because their hyper-rational thinking is basically saying, hey, this is good.
And I tell this very sad story. When my son was one and he was in my arms, sadly, there was this huge traffic jam, and we found out later on it was from one of my teachers was killed by a 19-year-old driving almost 100 miles an hour on a surface street near where our apartment was. And it was terrible.
And this kind of risky behavior... isn't always impulsivity, which is another myth, that adolescents have what is true. Their bodies, adolescents'bodies, are stronger and healthier than any other time of life. If you're going to get an infection, for example, you want to get it as an adolescent.
You are stronger than any other time. But the research shows you are three times more likely to die or to get seriously injured by a preventable cause. in general, across all adolescents.
So that's a really strange finding. So when parents are concerned, wow, this is a dangerous period, it is a dangerous period. There's no question about it.
The two reasons, your dopamine increase and release gets you to try risky things because they stimulate dopamine. And number two, the hyper-rational limbic area cortical deal that's being made from nature is to say, hey, hey. It's pretty exciting out there. Don't worry about how dangerous it is.
Just go out there. Don't worry about how it's uncertain. Go out there. And this combination gets kids to do things to various degrees, right, of danger.