These dramatic changes to the brain have led Baird to suggest adolescence is much like a second toddlerhood. When she first tells me this, I laugh. But on further reflection, I see her point. The toddler years are a sensitive period of growth in both the body and brain that helps babies transition into kids. And when I look closer at the behavior, I see the overlap. “That’s not fair”-type tantrums? Check. Pushing boundaries? Of course. A proclivity for hyperbole? Sure. Sensation-seeking? Yep. A “me, me, me” mentality? Oh, yeah.
Studies out of Baird’s lab and others suggest that those out-of-control emotions and bewildering motivations that so many parents wish they could quash are important to all that critical pre-adult learning. “The teen years require a lot of trial and error,” Baird says. “If everything wasn’t so dramatic and important and emotional, adolescents wouldn’t have the motivation they need to get back up and do it again when they fail.”
Processing Risk and Rewards
So why is everything so dramatic and important and emotional? It comes back to the neurotransmitter dopamine. A toned-down prefrontal cortex paired with an intensified emotion and motivation circuit is the perfect recipe for risk-taking. But while Dahl says it’s easy to suggest hormones make teens temporarily crazy or unable to use their frontal cortices appropriately, those notions are incorrect. Jonathan, for the most part, thinks things through. For example, he has asked me to use a pseudonym. Despite that rationality, his teenage brain strengthens the power of rewards so that he’s motivated to gain the experience required to grow and learn. And one way it’s doing so is in how rewards are perceived.
Recent work by B.J. Casey and her colleagues at Cornell University suggests the teen brain processes risks the same way adult brains do, but with one important difference: Areas of the brain involved with reward processing are much more active in teens than in younger children or adults.
"They don’t have the experience to have built an automatic response. They have to work the idea through their frontal lobes, and it’s just not as efficient”
The implication is that this increased activity results in teens overestimating the value of rewards. When we consider Jonathan’s decision to skip using a condom, his brain magnified the reward involved with a hookup. His brain was telling him that he couldn’t pass up this encounter: This sex will be the sexiest sex of all time. It became a reward fantastic enough to outdo all other considerations, including the potential consequences of teenage pregnancy or venereal disease.
“Really wanting those rewards is to our advantage when learning,” Baird notes. “One thing we do know about adolescence is that it’s a really great time to learn new things. And having that incentive to get yourself up, dust yourself off and try it all over again is invaluable. Otherwise, we might not try again and get the experience we need to actually do that learning we need to move from childhood to adulthood.”
Good Ideas and Bad Ideas
I first met Vassar’s Baird at a neuroscience conference in Washington, D.C., after hearing her present some research on the teen brain in a symposium about how neuroscience should shape the law. As part of her presentation, she queried the audience: “Tell me something,” she said. “Do you think swimming with sharks is a good idea or a bad idea?”
The majority of the audience, mostly adults, instantly yelled back, “Bad idea!”
If any of the adult shark pooh-pooh-ers had been having their brains scanned at that moment, scientists would have seen increased activation in the amygdala and insula — two key parts of the brain’s limbic system and important inputs to the mesocortical limbic circuit.
You may know the amygdala as the seat of the fight-or-flight response. But Baird tells me that the amygdala is responsible for the four F’s. “Fight and flight, everyone knows. The next F is feeding. And that last F stands for reproduction,” she jokes.
The amygdala represents the things we need to stay upright, breathing and propagating the species. And, with the basal ganglia, it helps manage important rewards. But it’s also involved in processing memory and emotional reactions and attaching social salience to objects and events. Baird likens it to the brain’s “burglar alarm.”
“This is a part of the brain that is very survival-oriented. It’s all about keeping you alive,” she says. “Not so much about thinking things through.”
The insula, like the amygdala, is also implicated in emotion and decision-making. Like the amygdala, it plays a key role in survival. But it does so by helping you form visceral memories about experiences — both good and bad.
“The insula gives you those gut feelings about things — you know, those instant feelings that are critical to your decision-making, to your innate sense of right and wrong,” Baird says. “But it is a highly developed structure. You aren’t born with these gut feelings about things. You have to learn them.”
"They have the experience to know what they can do and judge which kinds of things are within their capabilities"
Adults can rely both on the amygdala and the insula to help inform decision-making. But the teen brain reacts a little differently. When Baird and colleagues used fMRI to scan teenagers’ brains as they were asked a variety of “good idea or bad idea” questions, including biting a lightbulb, eating a cockroach and jumping off a roof, they found their insulae weren’t as active as the adults’. The majority of activation was occurring in the frontal lobes, where conscious thought occurs — and they were taking much, much longer to answer the questions.
“With adults, we get an answer that is very automatic and fast,” Baird says. “But teens don’t get that. Instead, they show a frontal lobe response. They actually think about it for a second. They don’t have the experience to have built an automatic response. They have to work the idea through their frontal lobes, and it’s just not as efficient.”
In fact, they took roughly 300 milliseconds longer than adults to work the idea through. While 300 milliseconds may not seem long, Baird says it’s significant. “People don’t realize that 300 milliseconds gets people killed on a regular basis,” she tells me. “That’s a decision to run a red light when you’re driving in your car. It’s plenty of time to do damage when you’re talking about a dangerous situation.”
Old Climbers and Bold Climbers
It’s clear teens have a neurobiological predisposition for pushing the envelope. And studies show that this increased risk-taking continues through the teen years and well into young adulthood. Around the age of 25, the prefrontal cortex matures to the point where one is better at applying the brakes when faced with a risky decision.
Radboud University risk researcher Bernd Figner says that studies consistently show that we take fewer risks as we get older. And the reason for that, he argues, is twofold.
“There is a maturation of the prefrontal cortex that is happening well into young adulthood that enables us to be better at inhibiting our most influential responses — that is one important thing,” he says. “But you also see these changes because you are more experienced. You now have these experiences, and you start to realize that it’s not always a good idea to take so many great risks. You understand the consequences better. You realize what’s at stake.”
So, it’s not that I’m old and boring; it’s just that I’m better experienced! My limbic system has picked up enough over the years to help guide good decision-making. And my frontal lobes have matured enough to actually do something with it all.
It would appear this effect is not limited to suburban moms. A study that looked at risky behaviors in experienced rock climbers found that they tend to scale back on riskier climbs as they age.