Teens. If they're not joyriding the family car or trying to give each other DIY ear piercings, they're providing way too much personal information on social media. Scientists have long said teens are impulsive because their brains aren't fully developed. But a large-scale study says that can't be the explanation. Instead, the recklessness of adolescence may just be a result of teens trying things for the first time.
Not A Bug, But A Feature
Scientists know that certain parts of the teenage brain take longer to develop than others. The prefrontal cortex — basically the CEO of the brain, responsible for managing complex functions like logic, planning, attention, and impulse control — is still developing well into your twenties, even when other areas associated with motivation and reward are already mature.
Specifically, your teenage prefrontal cortex is going through what neuroscientists call "pruning." Just like a wild hedge, the childhood brain is "overgrown" with gray matter — the part that's full of neurons and responsible for most of the brain's heavy lifting. As the brain matures, it prunes away unnecessary gray matter while increasing the amount of white matter, the part that connects one neuron to another.
It's this ongoing development that some scientists use as the reason for why teens are so dang impulsive. But in August 2017, researchers from the Annenberg Public Policy Center of the University of Pennsylvania published an extensive literature review that threw that theory — not to mention its premise — into question.
Adapting To Adulthood
For one thing, the researchers who discovered that pruning process never suggested it was a bad thing. They said it happened as a result of teenagers gaining experience. It's not a bug; it's a feature. As teens learn new things and experience more of the world, their brains become more and more developed. This is further proven by the fact that brain structure varies with the environment you're raised in — someone who grows up poor has a different brain than someone who grows up rich.
And another thing! Who's to say teens are all that impulsive anyway? Most of the risky behaviors researchers focus on, like injury rates, drug use, and teen pregnancy, aren't as widespread as they're made out to be. As the researchers write, "the stereotype of the impulsive, emotional, and distraught adolescent rests much more on the rise in adverse outcomes during this age period than on their overall prevalence." Most people will never get seriously hurt, addicted to drugs, infected with an STI, or pregnant during their teen years. Just as with adults, some teens are more predisposed to reckless behavior than others. But that's just a result of being human, not being young.
Instead, the researchers pose a different model to explain the boldness of adolescence. They call it the Life-span Wisdom Model, and it says that teens' increase in risk-taking is just them trying to make sense of the world. It's not a side effect of an undeveloped brain, but a way of evolving into adulthood.
"What's happening is that adolescents lack experience," said lead author Daniel Romer, Ph.D., in a press release. "So they're trying things out for the first time — like learning how to drive. They're also trying drugs, deciding what to wear and who to hang out with. For some youth, this leads to problems. But when you're trying things for the first time, you sometimes make mistakes. Researchers have interpreted this as a lack of control when for most youth, it's just exploration."