When a country’s adolescents trail much of the world on measures of school achievement but are among the world leaders in violence, unwanted pregnancy, STDs, abortion, binge drinking, marijuana use, obesity, and unhappiness, it is time to admit that something is wrong with the way that country is raising its young people.
That country is the United States.
We need to start thinking about adolescence differently. Fortunately, over the past two decades, there has been tremendous growth in the scientific study of adolescence. The good news is that the accumulated knowledge, which comes from behavioral science, social science, and neuroscience, provides a sensible foundation that can help parents, teachers, employers, health-care providers, and others who work with young people to be better at what they do. Parent more intelligently. Teach more effectively. Tapping into this accumulated knowledge will help us supervise, mentor, and coach young people in ways that are more likely to succeed.
During the last 15 years, we’ve learned a great deal about adolescence as a stage of development, in part because of tremendous advances in our understanding of how the brain changes during this period. Whereas it was once thought that brain development was more or less complete by the end of childhood, because the brain reaches its full adult size by then, new research shows that the brain continues to mature well into one’s twenties. But the changes that take place in the brain during adolescence are not so much about growth as they are about reorganization.
What distinguishes adolescence from other periods in brain development is not the fact that reorganization is taking place, but where it is happening. It occurs primarily in two regions - the prefrontal cortex and the limbic system. The prefrontal cortex sits immediately behind your forehead, and it is the main brain area responsible for self-regulation - it makes us rational. The limbic system is deep in the center of the brain, beneath the cortex. The limbic system plays an especially important role in generating emotions.
The story of adolescence is the story of how these regions learn to work together. It is a tale that unfolds in three overlapping phases.
Phase One: Starting the Engines
Around the time of puberty, the limbic system becomes more easily aroused. This is the phase that has been described as “starting the engines.” During this time, teenagers become more emotional (experiencing and displaying higher “highs” and lower “lows”), more sensitive to the opinions and evaluations of others (especially peers), and more determined to have exciting and intense experiences - something psychologists refer to as “sensation seeking.” As a consequence, students are much more likely to engage in risky and reckless activity, because they pursue what they perceive as potentially rewarding experiences without paying sufficient attention to the risks these activities might expose them to. One reason it is so important to provide stimulating, structured, and supervised after-school activities for adolescents is that doing so limits the amount of time students are in situations where they are likely to experiment with alcohol, illicit drugs, and sex.
Phase Two: Developing a Better Braking System
The second phase of brain development is gradual, actually starting in preadolescence, but not complete until age 16 or so. During this phase, the prefrontal cortex slowly becomes better organized, a consequence of synaptic pruning and myelination (strengthening of neural pathways). As information begins to flow more rapidly across longer distances in the brain, advanced thinking abilities - so-called “executive functions” - strengthen, which improves decision making, problem solving, and planning. In this phase, adolescents’ thinking becomes much more adultlike. During middle adolescence - say, from 14 to 17 - parents and teachers often find that adolescents become much more reasonable and easier to discuss things with. A lot of the drama that had characterized the early adolescent years fades.
Phase Three: Putting a Skilled Driver Behind the Wheel
Although a fine-tuned braking system is in place by the end of the second phase, the teenager can’t always use the brakes effectively and consistently. In the third phase, which is not finished until the early twenties, the brain becomes more interconnected. This is especially true with respect to the connections between the prefrontal cortex and the limbic system. This increase in connectivity results in mature and more dependable self-regulation. During the late teens and early twenties, adolescents get better at controlling their impulses, thinking about the long-term consequences of their decisions, and resisting peer pressure. Their rational thought processes are less easily disrupted by fatigue, stress, or emotional arousal. Young people still have much to learn about life, but for all intents and purposes, the intellectual machinery of adulthood is now fully in place.
As we mature into adulthood, the prefrontal cortex not only becomes more efficient, it also gets better at recruiting additional resources when a task demands more than this region can handle on its own. Compared with adolescents, adults are more likely to use multiple parts of the brain simultaneously. This is made possible by an increase in actual physical connections between non-neighboring brain regions. Compared with a child’s brain, an adult’s has many more thick white “cables” connecting widely dispersed brain regions. Generally speaking, children’s brains have a lot of relatively “local” connections - links between nearby brain regions. As we mature through adolescence and into adulthood, more distant regions wire together. The brain continues to grow more interconnected until age 22 or so.
This interconnectivity doesn’t develop overnight, however. As a result, during middle adolescence, mature self-control has a “now you see it, now you don’t” quality. When circumstances are ideal - no distractions, no strong emotions - a 16-year-old performs just as well as an adult. But being upset, excited, or tired interferes more with prefrontal functioning during adolescence than during adulthood, because the relevant brain circuits aren’t fully mature. Fatigue and stress can interfere with self-control at any age, but they have a particularly powerful impact when the skills they disrupt are still somewhat tenuous.
This is why it is important for teachers to understand that teenagers’ capacities for self-control and good judgment can be bolstered or undermined by circumstances. High-school-aged adolescents make better decisions when they’re calm, well rested, and aware that they’ll be rewarded for making good choices. When they’re emotionally or socially aroused, their judgment deteriorates. A student who appears to possess adultlike maturity in some situations may be surprisingly juvenile in others.
During the first half of adolescence, then, the prefrontal cortex improves by becoming more focused, which works fine as long as the challenges encountered are relatively simple and the environment doesn’t weaken the adolescent’s concentration (by fatigue or stress, for example). Self-regulation in early adolescence is stronger than it had been in childhood, but it is still somewhat tenuous and easily disrupted. During the second half of adolescence, self-control gradually becomes governed by a well-coordinated network of brain regions, which is helpful when we face a demanding task or distracting background conditions and we need additional brainpower. Part of becoming an adult is learning when we can do things on our own and when we need to ask for help. During this stage of life, brain maturation follows a parallel course.
Implications for Schools
The fact that there is extensive change in the prefrontal cortex during adolescence has important implications for educators. The prefrontal cortex is the brain’s chief executive officer, responsible for higher-order cognitive skills such as thinking ahead, evaluating the costs and benefits of different choices, and coordinating emotions and thoughts. It is also the brain region most important for self-control, which is the foundation for critical “noncognitive skills,” such as perseverance, determination, and the delay of gratification - a combination that some experts refer to as “grit.” Studies have found that grit is more predictive of success in school and work than any other attribute, including intelligence or talent. If schools were to include activities that encourage prefrontal development, students would have additional strengths beyond those conveyed through conventional academic instruction. The need for schools to foster the development of capacities like perseverance and determination is especially great for socioeconomically disadvantaged adolescents, who are less likely to grow up in home environments that contribute to their growth.
There are many reasons to be enthusiastic about incorporating deliberate efforts to improve self-control into our middle and high school curricula. In the rapidly changing world in which we now live, schools cannot possibly anticipate the specific skills that will be needed to navigate the ever-evolving labor force. Many experts agree that schools should focus on fostering more general competencies that have value in many different work settings. These include, but are not limited to, being able to work effectively with others, developing and carrying out long-term strategic plans, acquiring and using new information, thinking flexibly and creatively, and, of course, self-regulation.
Fostering these capacities is not only important for success in higher education or the labor force. This supplement to conventional education would have the added advantage of cultivating the sorts of inner strengths that help protect against the development of problems such as depression, obesity, delinquency, and substance use. These problems stem in part from deficiencies in self-regulation, so anything schools can do to strengthen this capacity will have benefits that are likely to be far-reaching. Reorienting schools to help strengthen self-regulation in addition to teaching academic skills will not simply prevent problems from developing, it will actually help promote adolescents’ physical and psychological well-being.
At this point, no single approach to strengthening self-regulation warrants unequivocal endorsement, but some general principles can guide schools interested in fostering students’ self-control.
First, because prefrontal development is stimulated by novelty and challenge, it is essential to expose students to demanding courses that push them intellectually. Many American high school students report that school is boring and unchallenging. I suspect this is not the situation in most independent schools (indeed, many parents choose to send their adolescents to independent schools for precisely this reason), but it is wise for educators to step back every so often and ask how well their school is faring in this respect. Schools that deliberately make academic life for students too easy, in order to ensure that they graduate with transcripts full of A’s, are squandering an important opportunity to foster positive psychological development. It is through challenge - even if it means occasional failure - that students acquire the ability to manage themselves without parents looking over their shoulder and persevere in the face of obstacles, skills they will certainly need in college.
I saw the benefits of exposure to novelty and challenge firsthand when our son, Ben, was a student at Friends’ Central School (Pennsylvania). The school’s small seminars, in which the focus is on critical thinking, and its tolerance of a diverse array of viewpoints in class discussions exposed Ben to the sorts of demands necessary to promote the noncognitive skills that are so vital for subsequent success. When Ben entered Trinity College, he found himself far better prepared for the demands of a liberal arts education than many of his classmates whose grades might have been higher but whose high school experiences had been far less challenging.
Second, there is increasing evidence that activities that promote mindfulness strengthen brain systems that regulate self-control. Mindfulness involves focusing one’s attention on the present moment in a nonjudgmental fashion - really attending to what your senses are picking up, without trying to interpret or think about the experience. The most consistent evidence for the benefits of mindfulness training comes from studies of meditation, which has been shown to reduce stress and help alleviate many psychological disorders, especially those that involve anxiety, trauma, and addiction. One of the advantages of using meditation to improve self-control is that it has beneficial effects beyond this specific outcome. Because mindfulness meditation helps reduce stress, it also improves sleep, cardiovascular health, and immune function. There is also evidence in support of disciplined physical activity that combines focused exercise with mindfulness. These include, for example, activities like yoga and certain martial arts, like tae kwon do.
Third, there is reason to think that aerobic exercise may also improve self-regulation. We know that aerobic exercise improves brain health in general by increasing blood flow. Schools need to make sure that all students - not just the athletic stars - have adequate time for exercise every day. And schools need to make parents aware of how important it is for adolescents to get adequate sleep each night; far too many American students are sleep-deprived.
The effects of aerobic activity on self-regulation in particular are more likely to be seen when the exercise demands challenging thinking as well as physical exertion, as in team sports that combine aerobic activity with strategy. Given this, it is not surprising that participation in school-sponsored organized athletics appears to help promote the development of self-regulation and initiative. In these cases, we can’t say for sure whether the positive effects are due to the exercise, the cognitive demands, or, most likely, a combination of the two.
Fourth, it appears that training in specific self-regulation strategies and skills (such as learning how to control anger) can also improve adolescents’ capacity for self-regulation more generally. Some schools now incorporate “social and emotional learning” (SEL) into their curricula. SEL programs teach adolescents how to regulate their emotions, manage stress, and consider other peoples’ feelings before acting. Although many of these programs were first intended to reduce problem behaviors such as aggression or delinquency (and have been evaluated with this goal in mind), they’ve also been shown to improve self-regulation in teenagers who don’t suffer from these problems.
There are many different programs available for schools interested in SEL to choose among. A good source of information is the Collaborative for Academic, Social, and Emotional Learning (www.casel.org), a nonprofit organization that evaluates SEL program effectiveness.
Know the Brain Science
Finally, it is important that schools involve both students and parents in the conversation about how to draw on adolescent brain science to promote positive development. One way to do this is to incorporate information on adolescent brain development into the curriculum and into evening programs for parents. My experience is that teenagers find this information fascinating, as do their parents. And with this knowledge, parents parent more intelligently, and adolescents improve their ability to self-regulate.
These are just a few of the lessons from behavioral science, social science, and neuroscience as they pertain to adolescent development, education, and well-being. But they are essential lessons for both parents and educators. By paying attention to them, we can take advantage of and build on our new understanding of what young people need in order to develop into happy, well-adjusted, and successful adults.