How Neuroscience Explains Your Teenager’s Impulsive Behavior

Finally, an answer to the number one question for every parent of a teenager: "What were you thinking?"

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The following was produced in partnership with the Lieber Institute for Brain Development and the Maltz Research Laboratories whose mission it is to translate genetic insights into next generation treatments for brain disorders.

Have you ever wondered why your teen seems to act impulsively? Why their actions seem to be taken without regard to consequences? While some of these acts are relatively harmless, others — swilling a few beers at a party or cliff-jumping into a lake at night — can be downright dangerous. Parents of teenagers often find themselves scratching their heads and wondering what on Earth their kids were thinking. A more productive question would be for parents to ask themselves, “What do I need to understand about my teen to help them through this turbulent time in their development?”

For one, adolescence is a critical period of neurological development that can explain a lot of behaviors that, to parents, may seem inexplicable. While we accept that a kindergartner’s brain is still forming, we often expect teenagers to think and act just like adults. The truth is, massive developmental changes occur at this time and require parenting skills to help. Most notably, by better understanding the biological aspects of teenage brain development, parents can not only improve their empathy, but also facilitate safe and moderately structured environments to assist them with the multitude of competing priorities emanating from their environment.

“It’s so important for parents — and teachers, and school administrators, and decision-makers, and young people themselves — to understand how an adolescent’s brain develops,” says Cynthia Germanotta, president of Born This Way Foundation (which she co-founded with her daughter Lady Gaga), a partner of the Lieber Institute for Brain Development. “That understanding is key for effectively supporting youth as they move into early adulthood, creating environments in which they can thrive and providing the resources they need to navigate the obstacles and opportunities of adolescence and lead happy, healthy lives.”

Dr. Daniel Weinberger, director and CEO of the Lieber Institute for Brain Development at Johns Hopkins University, concurs. “The human brain is a constantly changing organ, and a lot happens to it during adolescence,” he says. “When you are born, your brain is two-thirds to three-fourths the size of an adult’s brain, but it undergoes an enormous amount of change over the next 20 years — more than it will undergo for the entire rest of your life.”

Among the connections that have yet to be fully forged in a teenager’s brain are those that govern reason and emotion — and the ability to make decisions and behave based on reason and emotion. “When the adolescent brain, with its less-than-fully-developed prefrontal cortex, is exposed to hurt, aggression, disappointment, and other feelings, it doesn’t have all the resources of a mature brain to inhibit immediate and emotionally driven responses,” explains Weinberger.

“All human experiences affect the brain. If they didn’t, we couldn’t learn things or acquire new skills.”

Whether it’s firing back an insult when they feel slighted or slamming down on the gas pedal to show off their car’s speed to their friends, the seemingly impulsive acts of teenagers can be explained biologically. “To be able to inhibit impulsive tendencies or [say no to] a tantalizing experience, you need to be able to understand the implications of the action,” Weinberger says. “You have to understand cause and effect, not just in the immediate moment but in the future. It takes a high-functioning brain to understand that something that would be really fun in the moment could have consequences down the road.”

What does that mean for parents?

Given their still-developing prefrontal cortexes, teens often don’t have the wherewithal for such long-term thinking. “The older you get, the more likely you are to not chase every fox that runs out of the bush,” Weinberger says. “As an adolescent, you chase after many foxes, but eventually, as the prefrontal cortex develops, you learn that everything that glitters is not gold.” This is why it’s so important for parents to invite dialogue through empathy, understanding, and patience. When necessary, parents also need to offer hard guidance away from clear and present dangers — like drugs and alcohol.

“Adolescence is like a perfect storm that kids have to get through.”

Along with talking with your teen about the real brain dangers, you can support their development just by being there: being present, patient, and understanding. “Adolescence is like a perfect storm that kids have to get through,” Weinberger says. “What does it take to make it all work? It takes an environment that is stable, caring, empathic, and tolerant. It takes sensitivity to the difficulties they may have. Understand that adolescence is a real biological transition, not that they are just lazy or obstinate.”

But having patience and compassion doesn’t mean letting teens rule the roost, either. “Good parents lend teenagers their ego — that part of us that lets us think in an adaptive way based on behavior,” Weinberger says. “Adolescents need to know that their parents are there when they need them to provide structure and logic and limits.”

Parents also need to understand that as teens mature, their allegiances move from the home to peers. That is why friendships suddenly becomes so important to them. It’s critical to understand that hypersensitivity to social exclusion impacts adolescent risk-taking. Studies consistently show teens’ susceptibility to peer pressure is not, in other words, a character flaw, but a neurological drive. So next time you have a particularly frustrating run-in with your teen, take a deep breath, count to 10, and try to appreciate the complexities their still-developing brain.

A Day in the Life of an Adolescent Brain

It’s a typical day in the neighborhood and your son is out with his friends on their bikes. They are pressuring him to ride off a giant jump, one he knows he doesn’t have the skills to clear, not to mention the fact that he broke his arm playing lacrosse last season and is not yet fully recovered. Still, the stunt looks thrilling, and all the other teens, albeit more experienced riders, have already tackled it. Now they are laying it on thick, trying to coax your kid into taking the jump and taunting him for being chicken.

Your son feels a mix of emotions that would match that of most adults put in this situation: nervousness, excitement, fear, social anxiety, inadequacy. But how he copes with these is where he struggles. The pressure to conform combined with a developing prefrontal cortex, his decision making is maybe compromised, and studies show he’s more likely to follow along with what his friends are doing.

In other words, your son’s underdeveloped brain doesn’t have the cortical-processing abilities to run a cost-benefit analysis. His fear of being judged will likely push him to launch off the jump and, sigh, crawl home with a busted-up bike and re-injured arm.

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