Laurence Steinberg's 'Age of Opportunity'

Adolescent Brain Plasticity

Adolescence = 10-25 years.

Neuroplasticity = "the brain's potential to change through experience" (9). Ages 0-3 "are a time in which children's experiences make a major, lasting difference in how their brains develop and their lives unfold." Adolescence is "a second period of heightened malleability."

The reminiscence bump = "events b/t the ages of 10 and 25 are recalled more easily than events from other periods" (19). Why? "When certain neurotransmitters, like dopamine, are released at the same time an event is experienced, the event is more easily remembered than when levels of these chemicals are not as high. These chemicals are released when we experience something that elicits strong negative or positive feelings." "[B]rain regions responsible for strong emotions are especially sensitive during adolescence. As a result, the adolescent brain is chemically primed to encode memories more deeply. The reminiscence bump doesn't exist because more emotional events take place in adolescence, but b/c ordinary events trigger stronger emotions" (21).

It was formerly believed that developmental plasticity mainly occurred early in life -- b/c we knew the brain was getting bigger during this period and b/c "many basic abilities are improving (like vision), emerging (like language), and consolidating (like gross motor skills)" (22). "Once these early-developing brain systems have matured, it is very hard to alter them. This helps explain why the effects of extreme deprivation early in life are so difficult to reverse. Infants who have been kept in orphanages without adequate environmental stimulation will not develop normally if they aren't removed from these harmful environments b/f they're two years old." E.g., study of Romanian children -- those place in orphans past age two compared to those placed in foster-care --  the former had lower IQs and more emotional and behavioral problems. Brain plasticity again increases during adolescence and stays this way until early adulthood.

"A plastic brain is a brain that can be molded" -- "just as [industrial] plastic can be transformed from a soft, malleable state into one that is hard and rigid, so too does the brain change from being relatively more moldable to being relatively more fixed"  (23).

Developmental plasticity "refers to the malleability of the brain during periods in which the brain is being built, when its anatomy is still changing in profound ways" (25). One type of change involves the brain's "wiring," i.e., "how its one hundred billion neurons are interconnected."  "During the early years of life, our brains don't produce many new neurons, but they make billions of connections between neurons...Because it is inefficient for each neuron to be connected to every other neuron (nor is it physically possible...), it is important that the brain's network be well organized...Much of developmental plasticity therefore involves eliminating unnecessary connections, a process called 'pruning'" (26).

Adult plasticity is different than the developmental plasticity of adolescence. First, it "doesn't fundamentally alter the neural structure of the brain, whereas developmental plasticity...involves the growth of new brain cells and the formation of new brain circuits" (27). Second, "brain systems are far less malleable during periods of adult plasticity than they are during periods of developmental plasticity. In fact, the developing brain is chemically predisposed to be modified by experiences, like clay when it is still soft, whereas the adult brain is predisposed to resist modification--like clay once it is hardened." Third, "b/c the developing brain is so much more malleable, it can be influenced by a far wider range of experiences that we aren't even aware of. Once the brain has matured, we need to pay attention to and give meaning to our experiences in order to be affected by them in an enduring."

"The brain functions by transmitting electrical signals across circuits that are composed of interconnected cells, called neurons" (31). In the adult brain, each neuron has around 10,000 connections. Gray matter = the neurons and the projections that connect them to one another. Synapse = gap b/t neurons. Electrical impulses pass from one neuron to the next. "The transmission of current from one neuron to another can be thought of as the passage of information along that particular pathway, like runners on a track team passing a baton during a relay race. Everything we think, perceive, feel, or do depends on the flow of the electrical impulses across the brain's circuits."

Synapses = the tiny gap b/t neurons. "In order for an impulse to be relayed to a neighboring neuron, the electrical charge has to 'jump' across the gap" (31-32). This jump is "enabled by the release of chemicals called neurotransmitters" like dopamine and serotonin (32).

"In your home, the more often you use an electrical circuit...the more likely it is to wear out and need replacing. Just the opposite is true in your brain, though. The more often you activate a particular brain circuit, the stronger it becomes--the connections b/t the neurons actually multiply as a result of the experience...In other words, the very connections b/t neurons that allow us to do something--think a particular thought, feel a particular feeling, perform a particular act, remember a map of city streets--are strengthened each time we do it" (33). Conversely, "[w]hen a brain circuit is not used, its connections become weaker and weaker."

"Pure repetition in and of itself is not very effective in stimulating brain change. In order to take full advantage of the brain's capacity for plasticity, the demands we place on our brain must exceed the brain's capacity to meet them. The slight mismatch b/t what we can do and what we push ourselves to do is what stimulates brain development" (35). One reason the brains of adults are not as plastic is that we we're less likely to have novel experiences and thus less likely to encounter this mismatch (44).

"[D]ifferent regions of the brain are plastic at different ages...As a consequence, the abilities that are most likely to be developed, strengthened, or weakened during adolescence are not the same as those that are developed, strengthened, or weakened at other ages. Adolescence is important not only b/c the brain is plastic, but because of where the plasticity occurs" (35). "The adolescent brain undergoes particularly extensive maturation in regions that regulate the experience of pleasure, the ways in which we view and think about other people, and our ability to exercise self control" (37)--in other words, the reward system, the relationship system, and the regulatory system.

"[W]ith the exception of ADHD, separation anxiety disorder, learning disorders, and autism spectrum disorders, the age range for the typical onset of every other major disorder falls somewhere in the period b/t the ages 10 and 25" (37).

Thesis

Adolescent brain plasticity is both good and bad. It "makes adolescence a period of tremendous opportunity--and great risk. If w expose our young people to positive, supportive environments, they will flourish. But if the environments are toxic, they will suffer in powerful and enduring ways" (9).

"The drop in plasticity as we mature into adulthood is just as significant as the increase in plasticity as we enter adolescence. In fact, adolescence is the brain's last period of especially heightened malleability. One reason psychological problems are easier to treat in adolescence than they are in adulthood is that the problems become more entrenched as we get older.

"The brain's malleability doesn't only permit change for the better, it also allows change for the worse. Infants who receive cognitive stimulation, like having their parents read to them, thrive b/c this exposure is taking place at a time when the brain is still being shaped by experience. But babies who are neglected or abused early in life can suffer especially long-lasting damage, b/c the maltreatment has occurred at an age when it is easier for the brain to be harmed by deprivation and other kinds of negative experiences. In other words, discovery that the brain is highly plastic during adolescence is good news in principle, but it is only good news if we take advantage of it, by providing the sorts of experiences to young people that will facilitate positive development and protecting them from experiences that will hurt them" (10-11).

Adolescence Is Longer than Ever

Adolescence is three times longer than it was 150 years ago and two times longer than it was in the 1950s. Why? Multiple causes. Earlier onset age of puberty between 1850 and 1950 due to improvements in maternal and child health (51). Children have been starting puberty earlier since 1950 b/c they are fatter and are exposed to more light at a young age. "Obese children have more body fat and therefore produce a lot more leptin, which stimulates kisspeptin production" (53); an increase of kisspeptin stimulates the onset of puberty. "Children who live near the equator are exposed to relatively more sunlight each year, and they have lower melatonin levels as a result, so their kisspeptin production is not suppressed as much as it is among children who live closer to the poles." Children "spent more time in front of screens, esp. at night, which increases their daily light exposure" (54). Another contributor of early puberty: endocrine disruptors, "chemicals that throw off our body's normal hormonal functioning. These chemicals influence the timing of puberty by altering the production and effects of naturally produced sex hormones and, as well, by mimicking the hormones themselves" (54).

Early maturers "are often treated differently by others, which affects the way they act and feel about themselves. Early-maturing adolescents are more likely to wish they were older, hang around with older peers, disengage from school, and be more peer-oriented. The increased time they spend w/ older peers often draws early maturers into behaviors they wouldn't otherwise try until a much later age, like sex, delinquency, truancy, and smoking, drinking, and using other drugs" (56).

"Early-maturing adolescents also experience a greater gap b/t when they mature physically and when they mature in other ways. This discrepancy can cause problems, as when an adolescent develops an interest in sex b/f he can think ahead well enough to remember to carry condoms, or when a girl starts to attract boys b/f she has the emotional wherewithal to decline their advances" (58).

Delaying adulthood can be a good thing if young people use their minds the right way. Since their brains remain plastic, "If this malleability is maintained by staying engaged in novel, challenging, and cognitively stimulating activity, and if entering into the repetitive and less exciting roles of worker and spouse help close the window of plasticity, delaying the entrance into adulthood is not only OK -- it is potentially a boon" (62).

How Adolescents Think

Adolescent brain development primarily occurs in two regions: the prefrontal cortex (responsible for self-regulation) and the limbic system (plays important role in generating emotions).

Phase 1. As puberty starts, the limbic system "becomes more easily aroused." Teenagers become more emotional -- they experience higher highs and lower lows, they become more sensitive to the judgments of others, they become more sensation seeking ("more determined to have exciting and intense experiences") (70). This phase ends when the child stops physically maturing.

Phase 2. The prefrontal cortex "slowly becomes better organized, a consequence of synaptic pruning and myelination" (70-71). Consequently, "advanced thinking abilities -- so-called 'executive functions' -- strengthen, which improves decision making, problem solving, and planning ahead." This phase begins in preadolescence and generally ends around age 16.

Phase 3. The brain becomes more interconnected, esp. the connections b/t 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." This process is not complete until one's early twenties.

The limbic system -- detects "elements of the immediate environment that are important to pay attention to" (71). The limbic system does this by creating "an emotion that motivates us to act in response to what's going on in the environment." The limbic system essentially sends a report up to the prefrontal cortex, "which evaluates and interprets the emotion and makes a decision about what to do in response to it" (72).

During puberty one's limbic system is "much more easily aroused, esp. in response to rewards, b/c sex hormones have a particularly powerful impact on brain circuits that rely on dopamine." Dopamine signals "the experience of pleasure and motivate[s] us to go after it. When I see a cue that makes me feel good (e.g, when I see an erotic picture), my brain releases dopamine. "Puberty triggers a dramatic increase in the concentration of dopamine receptors," which "makes these pathways much more easily activated" (73). Moreover, a structure inside the limbic system called the nucleus accumbens, which is "the most active part of the brain for the experience of pleasure, grows bigger as we age from childhood to adolescence and then grows small again as we age from adolescence to adulthood. This is why pleasures in adolescence -- from having sex to eating ice cream to "zipping along in a convertible on a warm summer evening" -- actually feel more pleasurable during adolescence.

Two research findings. First, our "sensitivity to the potential rewards of a risky choice -- like the possibility of winning a low-probability bet -- peaks around age sixteen...Compared to children or adults, it is easier to get adolescents to gamble even when their odds of winning are small or uncertain" (83). Second, "children make more impulsive decisions than teenagers, and teenagers make more impulsive ones than adults." Conclusion: "Teenagers' attraction to rewards impels them to do exciting things, even when they might be risky. But their poor self-control makes it hard for them to slow down and think before they act."

Protecting Adolescents from Themselves

We become more reckless as we enter adolescence -- e.g., more likely to drink, smoke, do drugs, have unprotected sex, engage in self-injury, suicide, speed while driving, less likely to wear seat belts (89). Adolescents d/n engage in risky behavior b/c they're less rational than adults or less likely to know what behaviors are risky (91). Two reasons why adolescents engage in more risky behavior: poor impulse control (b/c prefrontal cortex still developing), they're "far more sensitive to rewards than adults are -- compared to life as an adolescent, life for an adult is like walking past a plate of warm chocolate-chip cookies w/ cotton in your nose...This supersensitivity to rewards makes adolescents naturally more attentive to the good things that might arise from their risky behavior." E.g., they know just as well as adults the costs of having unprotected sex, "but they place a lot more emphasis on the potential rewards" (92).

The Peer Effect. Adolescents far more reckless when peers around -- e.g., adolescents far more likely to crash car when peers around, while adults are no more likely (93). Puberty causes "changes in regions that oversee our reactions to other people" (95). Adolescents more likely than adults to pay attention to "other people's expressions, thoughts, feelings, and opinions of us." This "fixation on others' emotions can dull their perception of potentially important information elsewhere in their environment" (96).

"Rather than sate our need for rewards, exposure to one sort of rewarding stimulus tends to stimulate a desire for others...This is why we tend to eat and drink more when we are enjoying ourselves w/ other people than when we aren't having a good time. Feeling good makes us want to feel even better" (98).  "Adolescents get a dopamine squirt from being with their friends, just as they do from other things that make them feel good" in a way that adults do not (98). Thus, "being around friends when you are a teenager makes everything feel so good that you become even more sensitive to rewards than you ordinarily are, which leads you to take chances you wouldn't otherwise take."

Studies show that adolescents "learn more from group projects than from working alone" (99).

Educating adolescents about risky behaviors d/n prevent them from engaging in such behaviors -- e.g., sex education, drivers education, DARE. "Programs aimed at enhancing adolescents' general capacity for self-regulation are far more likely to be effective in reducing risky behavior than are those that are limited to providing them w/ information about risky activities" (104-105). Such programs "focus on generic skills that enable adolescents to exercise self-control rather than teaching them about the dangers of specific types of risky activity."

We must also change certain environmental factors -- e.g., "more and better afterschool programming that provides structure and adult supervision," strategies like "raising the price and minimum purchase age of cigarettes, more vigilantly enforcing laws governing the sale of alcohol to minors, expanding adolescents' access to mental health and contraceptive services, and raising the driving age" (105).

The Importance of Self-Control

The marshmallow test -- people who were delayers when they were four went on to be far more successful -- higher SAT scores, better at dealing with stress, as adults less likely to be overweight, less likely to have behavioral problems, drug addictions (108).

"On average, children are more attracted to immediate rewards than teenagers, who are more attracted to them than adults" (109).

Self-control is essential for success. Those w/ self-control are more likely to finish college, and those w/ college degrees earn twice as much as those with just high school degrees.

"Adolescents who score high on measures of perseverance but only average on measures of intelligence are more successful than those who score high on measures of intelligence but only average on measures of perseverance" (120). Perseverance, or determination, requires self-regulation. "The ability to control our emotions, thoughts, and behaviors is what enables us to stay focused, esp. when things get difficult, unpleasant, or tedious. We rely on self-regulation to stop our minds from wandering, to force ourselves to push a little more even though we're tired, and to keep still when we'd rather be moving around. Self-regulation is what separates the determined -- and the successful -- from the insecure, the distractible, and the easily discouraged" (121).

"People who score high on measures of self-regulation complete more years of school, earn more money and have higher-status jobs, and are more likely to stay happily married. People who score low on these measures are more likely to get into trouble w/ the law and to suffer from a range of medical and psychological problems, including heart disease, obesity, depression, anxiety, and substance abuse" (121).

"Adolescence is a key time to develop self-regulation," as "the brain systems that govern this capacity remain highly plastic throughout adolescents" (121).

Intelligence is "highly determined by genes" (122). Self-control "has a substantial genetic component, but the influence of genes on self-control is only about half that of intelligence...[T]aking an intellectually dull adolescent and moving him into a stimulating environment will do little, if anything, to alter how smart he is. but moving an adolescent w/ poor impulse control into an environment that encourages better self-regulation can make a real difference. Studies show that even the most impulsive, aggressive juvenile delinquents can be helped to develop better self-regulation" (123).

How Parents Can Make a Difference

Research shows that parents of children with good self-control display three main qualities: warmth, firmness, supportiveness.

Be Warm. "Warm parents are affectionate, generous w/ praise, and responsive to their children's emotional needs. This contributes to self-regulation, b/c when children feel loved, they develop a strong sense that the world is a safe and benevolent place. This allows them to function away from their parents w/o worrying that trouble lurks around every corner" (126). Key points: You cannot love your child too much, Be physically affectionate, Try to understand and respond to your child's emotional needs, Provide a safe haven, Be involved in your child's life.

Be Firmne. "Firmness refers to the degree and consistency of limits that parents impose on their child's behavior. Firm parents have clearly articulated the rules they expect their child to follow, and they make demands on the child to behave in a mature and responsible fashion. Children raise in this way know what their parents expect of them and understand that there are consequences for violating their expectations...Structure makes children feel safe" (129). "We learn to regulate ourselves by being regulated. Children acquire self-control by taking the rules that their parents have imposed on them and imposing them on themselves. When the external control isn't there to begin with, the internal control won't develop." Key points: Make your expectations clear, Explain your rules and decisions, Be consistent, Be fair, Avoid harsh punishments.

Be Supportive. Refers to "how much parents tolerate and encourage their child's growing capacity for self-management. Parents who do this well use" scaffolding, i.e., "giving kids slightly more responsibility or autonomy than they're used to -- just enough so that they'll feel the benefits if they succeed but not suffer dire consequences should they fail" (132). E.g., an 11-year-old who's never been home alone, allow her to be home by herself for an hour while her parents are visiting the next-door neighbor. Key principles: Set your child up to succeed, Praise your child's accomplishments but focus on the effort, not the outcome, Don't be overly intrusive, Relinquish control gradually, as your child gets better at managing her own life, Help your child think through decisions rather than making them for him, Protect when you must but permit when you can.

Research shows that children with authoritative parents (not autocratic or permissive) have greater self-control (138).

Reimagining High School

Compared to international students, our elementary and middle school student generally place slightly above average, but our high school students place well below average, scoring esp. low in math and science (142). For decades we've dumped many into our schools and tried different things, but nothing works. E.g., charter schools d/n outperform public schools when you account for student family. "If parents don't raise their children in ways that enable them to maintain interest in what their teachers are teaching, it doesn't matter who the teachers are, how they teach, what they teach, or how much they're paid. Without changing the culture of student achievement, changes in instructors or instruction won't, and can't, make a difference" (146).

"High-school students from many Asian and European countries outperform their American counterparts mainly b/c the cultures of achievement are very different in these other countries. These cultures give rise to higher expectations at home and more support for achievement within the adolescent peer group. In addition, in many other countries, esp. in Asia, parents demand much more self-control from their children at much younger ages. By the time children in other cultures have matured into adulthood, they have much strong self-control than Americans do" (146). (These cultural differences also explain why children who have recently immigrated to the US do better in school.)

Evidence. Comparison of self-control b/t Americans and Chinese -- Chinese ten-year-olds score 10 percent higher, Chinese 14-year-olds score 20 percent higher, Chinese 18-year-olds score 45 percent higher (147). The fact that this gap widens in adolescents is probable due to the way adolescents in both cultures are raised. Perseverance is more necessary in elementary school -- e.g., b/c assignments shorter. There are also more distractions in high school, and so self-control is more important.

Schools need to "foster the development of capacities like perseverance and determination" (150). This is esp. important for lower-income students, as their parents are more likely to have an autocratic parenting style (149).

KIPP seeks to make students college-ready by supplementing their curriculum w/ factors shown to bolster academic success, i.e., the seven character strengths . One study has shown that, all things being equal, KIPP students have more academic success than their public school counterparts (152), but KIPP students were no more likely to display the seven character strengths. That is to say, KIPP d/n increase things like self-control.

Not yet strong evidence base for programs that increase self-control, although five efforts show promise: "exercises designed to improve one or more specific aspects of executive functioning, practices devoted to increasing 'mindfulness,' aerobic exercise, physical regimens that require intense concentration, and specific strategies designed to boost self-control or strengthen the ability to delay gratification" (155). See 156-161.

Three common principles necessary for all of these strategies to work. First, they must be stimulating, that is, demanding and challenging. They need not be pleasurable. "Some students will enjoy being pushed to work harder; others will push back. As long as they're being challenged, they'll benefit from the activity" (161). Second, activities must be scaffolded -- "challenging but not so difficult as to frustrate or discourage the child. Once the child has mastered a particular task, the degree of difficulty shoudl be increased, but just slightly." Third, the activity "must be sustained over time through deliberate practice" (162). Deliberate practice is not mere repetition but "repetition that is structured to improve performance. It is slow, methodical, and purposive." "Schools also can encourage practice by incorporating training exercises into other classroom activities throughout the day." Emphasizes the importance of physical exercise.