Science tells us that brains, minds, are built, not born. And at the center of this dynamic architecture are a set of skills called executive function and self-regulation. >> RAVER: Children's self-regulation and executive function are key ingredients in their lifetime performance. It's not just about learning language or learning numbers or learning colors. >> PHILLIPS: We have to be able to work effectively with others, with distractions, with multiple demands. These actually are skills that contribute to the productivity of the American workforce. ZELAZO: Educators, I think, are looking for just this sort of thing. And when we describe what we mean by executive function, they say, "Yes." "That's it. That's exactly the problem. These kids, they can tell me these rules, but they can't actually use them." What is executive function? >> PHILLIPS: Probably the best way to think about it is sort of like an air traffic control system in the brain. Just like an air traffic control system has to manage lots of airplanes, going on lots of runways, and really exquisite timing, and so on, a child has to manage a lot of information and avoid distractions. We really think of it as involving working memory, inhibitory control, and mental flexibility. Take a situation where a child is having to take turns. So, first of all, the child has to have inhibitory control. The child has to be able to stop whatever he or she is doing and let the other child take a turn. But when it's your turn again, you also have to remember what it is you're supposed to be doing. So that pulls on working memory. If the children who are taking turns after you do something unpredictable you have to be able to adjust what you're going to do next, and that requires mental flexibility. Children who are struggling with these capacities often look like children just aren't paying attention or children who are deliberately not controlling themselves. >> LEONG: If you don't have self-regulation, you act out and the teacher puts you in time-out and so then you miss part of the learning that's going on, and then you are more upset because you're behind and so you act out, and so you get this downward spiral. How does executive function develop? >> PHILLIPS: In little children, and even in the infant and toddler years, you begin to see the roots of executive functioning skills. What's going on in our brains is unbelievably intricate and complicated. >> BUNGE: The prefrontal cortex, or the front third of the brain, is important for executive function. But it's more than just prefrontal cortex. This region doesn't act alone. It's involved in controlling your behavior through its interactions with all other parts of the brain. The brain goes from a situation where you've got nearest neurons communicating very strongly with each other and ignoring the rest of the brain to these widespread networks that are connecting these different areas. Executive function changes over the life course. It improves radically over the first few years. It continues to improve throughout adolescence. It's not until early adulthood that you have the adult-type networks that are very strongly activated that connect different brain regions together. Also, we believe that executive functions can be trained. >> FISHER: It's just like going to the gym. So the more you practice in these areas the stronger the capacity is likely to become because you're hoping to strengthen those neural connections. >> PHILLIPS: Slowly but surely, you're going to be able to step back and that child is going to go into the world with these skills where they can get along with other people, change rules, and they can be flexible, and they can accomplish new things, and they're unfraid. If we don't learn these skills during the childhood and adolescent years when they're coming online we are really ill-equipped as an adult, to hold a job, to maintain a marriage, to raise children, to get along with each other, to basically be part of a civil society.