Understanding the Teenage Brain

Today it is common knowledge that teenage brains are neurologically immature. Essentially everyone recognizes and accepts that the teen brain is “under construction.” But the idea that the adolescent brain is under development is a relatively new concept. It’s only been in the last three decades that we’ve understood the degree to which the brain continues to develop beyond childhood. 

How the Brain Develops

As brain imaging techniques advanced, theories emerged alongside to explain why teens can be so difficult. Studies show that this is what happens as our children’s brains develop (and this is seen across cultures): 

1. During childhood we see grey matter (commonly termed brain cells or neurons) increase enormously fast. 
2. This makes the cortex become thicker and more voluminous up until the early teen years. 
3. But as the teen years progress, the number of brain cells and neuronal connections decline (and cortical thickness and volume diminish) at a vanishingly fast rate, eventually levelling off as our children arrive in their mid-20s. 
4. While this reduction of grey matter (brain cells) occurs, the development of cerebral white matter (myelin) increases through a process known as myelination.

From childhood, the brain has more neurons and more connections between those neurons than it needs. They develop because the brain collects information through experience and holds onto all that it can. As the brain matures, it must prune excess neurons and connections to make the brain circuitry more efficient.

Think of it like your broadband connection. It works great until everyone is using the WiFi. Once you’ve got five phones, three laptops, and two TVs all downloading content, it can’t keep up. Too many connections! So, in the same way that you start shutting a few of those devices down to keep the signal going where you need it most, the brain starts pruning cells and connections to improve connectivity and efficiency.

As neurons prune themselves, myelin begins to develop. Myelin acts as an insulator, making the process of sending and receiving signals more efficient. This myelin works the same way that the rubber or plastic wrapped around an electrical wire works. It directs the signal from A to B without it diffusing into the environment. And it speeds the signal up! 

Why It Matters

Think about what happens when the road network in your area is being upgraded and redeveloped. It usually means delays. It requires you to go slowly and work through the gridlock with patience and understanding, knowing that in time, the work will be completed and traffic will flow better than ever.

Right now, your teen’s brain is like that road network. And it’s going to take a few years of upgrades before he's where you want him to be. The important thing to remember is that we can help these developing brains by keeping things level and balanced.

There are two areas of behavior that are particularly problematic during the teen years—risk taking behavior and a lack of concern for others. We’re going to dive into how these areas relate to brain development, and what we can do about it.

Risk-taking in Adolescence

We often hear that adolescent decision-making is compromised because of the difference between limbic system development (where emotions are) and prefrontal cortex development (where thinking occurs). It’s this developmental discrepancy that explains unsafe, unhealthy, and unwise choices in adolescence.

However, if we look at the age where our young people are experiencing the most misalignment in neural development, it is around the ages of 13-15 years. That’s the time where the gap between prefrontal cortex development and limbic system development is greatest. So theoretically, we should be seeing more risk-taking inclination and behavior in those early teen years than at any other age.

Instead, kids in their early teen years aren’t generally engaging in risky behaviors nearly to the same extent as kids in their late teens or early 20s. In large part, this is because risk-taking inclination and curiosity combine with opportunity in later teen years to create risky behaviors. After all, 13-year-olds can’t engage in risky driving, alcohol abuse, or cigarette use and vaping (at least not legally) in the same way that an 18-year-old can.

This link between opportunity and risk-taking behavior is also affected by gender. Males engage in more risk-taking behaviors, but there is no significant difference in risk-taking propensity between genders. That is, girls are just as likely to have the desire to engage in risky behavior, but they don’t follow through like boys. Guys simply have more chances—and take more chances—than girls.

Moreover, some research suggests that challenging teen behavior is a result of self-fulfilling prophecy. Studies have shown that teens who agreed with more negative statements about the developing adolescent brain showed increased risk-taking behavior when compared with teens who didn’t agree with those statements. 

Risky adolescent behavior, it seems, is less about brain development and more about a combination of curiosity, peer influence, status seeking, opportunity, and self-fulfilling prophecy that leads our kids up the proverbial garden path when it comes to their challenging behaviors.

By emphasizing connection, we can make it through the teen years with our relationships not only intact, but thriving.

Empathy in Adolescence

Cognitive empathy, or the mental ability to take others' perspectives, begins rising steadily in girls at age 13, according to a six-year study published in Developmental Psychology. This capacity is processed in the prefrontal cortex; the executive of the brain that is relatively underdeveloped (meaning too many brain cells and not enough myelin) during adolescence. Curiously, we don’t see similar gains in cognitive empathy in boys until age 15. 

Not only do teen boys lack cognitive empathy, but that same research found that from ages 13 through 16, boys’ affective empathy drops (which is the ability to recognize and respond to others' feelings). It does recover in later adolescence. But for girls, it’s always there: stable and high. 

The brain is implicated in empathy development. But the evidence suggests that there are no specific differences in patterns of neural activity between the sexes for empathy, even though females score higher on pretty much all measures of empathy. This tells us that empathy is less about brain development and more about social conditioning and cultural expectations.

Four Ideas for Parents

There are a lot of people who make a big deal about understanding the brain. While it’s fascinating to learn and discover how our brains work, here is my view: You don't need a PhD in neuroscience to be a good parent. In fact, having an incomplete or overly simplified view of brain development can even make parenting harder. Brain research can inform parenting practice in general, but it doesn't tell us what to do or how to do it in the moment.

All of this brings us to the final question: how can we, as parents, use this information on the teen brain? I’ll share four ideas to guide your interaction with your teen when it comes to brain development.

1. Remember that there are both positive and negative dimensions of risk-taking behavior. It is possible to satiate teenage curiosity and desire for excitement in safe ways. Healthy risk taking is:

• Socially acceptable
• A necessary part of adolescence 
• Something that allows teens to explore and develop their own identities
• Something that gives teens practice making their own decisions 

By practicing taking healthy risks, teens have an opportunity to develop their cognitive control system, narrowing the developmental gap between reward seeking and self-regulation. This means that when there is a decision to be made, we should pause and invite them to explain what they’re thinking—and empower them to choose wisely and safely. And if a teen confesses to doing something unsafe, unhealthy, and unwise, avoid shame. A continuing discussion where we are curious, not furious, can make a big difference.

2. “Boys will be boys” is no excuse for poor behavior. Don’t be so quick to excuse gender differences as being due to brain differences. While this plays a small part, it can also give boys an excuse for suboptimal behavior. Our boys can do better.

3. Instead of focusing on ‘deficits’ of the adolescent brain, focus on the benefits. Teens have more brain cells than adults, and they are better able to build synapses between neurons, which means they are able to learn easier and quicker. Let them know this and point your expectations towards development and growth rather than foolishness and risk.

Finally, here is one crucial step we should always take, regardless of brain development:

4. Emphasize connection over correction and direction. Make sure they feel seen, heard, and valued. Your teens should know that you love them. Say it regularly. And remind them that you love them—no matter what.

Raising teens can be tough. But the good news is that the vast majority make it through their adolescent years to become respectful, well-rounded adults. And by emphasizing connection, we can make it through the teen years with our relationships not only intact, but thriving. 

Dr. Justin Coulson is a bestselling author, husband, and father of six. His latest book is Miss-Connection.