Brain Development Science Sheds Light on Teen DrivingBy AutoObserver Staff February 25, 2011
By Laurence Steinberg, Ph.D.
In 2010, I chaired the National Academies Committee on the Science of Adolescence, and the main focus of our work was on adolescent risk taking. Not surprisingly, we spent a good deal of time talking about reckless driving, and how to prevent it.
Most people are well aware automobile crashes are the leading cause of death and disability for adolescents. But there are many misconceptions about why adolescent drivers have proportionately more crashes than adults. They are of course less experienced, but this is not the whole story, because even when drivers of similar experience are compared, teenagers still have more crashes than adults. Nor is drinking the explanation in fact, alcohol accounts for a far smaller proportion of car accidents among adolescents than among than among older drivers. What studies show is reckless driving driving too fast, driving while distracted, failing to take into account the dangers associated with driving in bad conditions, and the like is by and large the main contributor to teen automobile crashes.
The conventional answer to this problem has been driver education coursework designed to familiarize adolescents with the rules of the road and the principles of safe driving. But experts now agree education alone may not solve the problem. In the case of reckless driving, as with many other forms of risk-taking, teens usually know they are driving in a way that is potentially dangerous. (In fact, many define safe driving as being able to drive recklessly without having an accident!) Ive spoken to many parents who tell stories of how their teen willingly drove 100 miles an hour just to see what it felt like, or tried to take a curve at breakneck speed, just to see if he could do it. Why would someone knowingly drive in a way that contradicts everything he or she has been taught about driver safety?
In recent years, scientists have increasingly turned to the study of adolescent brain development for answers. Before the development of brain-imaging technology, scientists could only speculate about the workings of the adolescent brain. Now, however, using the same scanners that identify torn ligaments and tumors, researchers are able to see inside adolescents brains and watch what happens when they think. We now know that, other than the first three years of life, no period of development is characterized by more-dramatic brain changes than adolescence. The specific nature of these changes helps explain why adolescents may be especially inclined toward risky behavior.
The area in the very front of the brain (the prefrontal cortex, which sits behind your forehead and between your temples) is the brains CEO. It is active when we are thinking complicated thoughts weighing alternatives, calculating risks and rewards, constructing a plan, making complex decisions. And this is where some of the most important brain changes take place during adolescence. By the end of adolescence, brain activity in the prefrontal cortex is more efficient, and communication between it and other parts of the brain especially those related to the way we experience and perceive emotions, rewards, and threats is better. The maturation of the prefrontal cortex results in improvements in skills such as logical reasoning, planning ahead, and thinking about several different things at once. Although these improvements dont occur overnight, there are noticeable changes in the way adolescents think. Compared with preadolescents, adolescents brains work better and faster.
Brain maturation doesnt end in adolescence, though. Imaging studies show the brain is still maturing well into the mid-20s, especially in regions responsible for regulating emotions, controlling impulses, and balancing risk and reward. Psychologists draw a distinction between cold cognition (when we are thinking about something that doesnt have much emotional content, such as how to solve an algebra problem) and hot cognition (when we are thinking about something that can make us feel exuberant or excited, angry or depressed, such as whether to go joyriding with friends or throw a punch at someone who insulted a girlfriend). The systems of the brain responsible for cold cognition are mature by age 16. But the systems that control hot cognition arent they are still developing well into the 20s. Thats why the teen who gets straight As in school can also such dumb things when out with buddies like drive in ways he or she knows are dangerous.
At the same time the adolescent brain is maturing in ways that enable a teen to become more capable of reasoned thinking, it is also changing in ways that encourage risky behavior. Do you remember how good your first passionate kiss felt? How much you loved the music of your youth? How hard you laughed with your high school friends? Things that feel good, feel better during adolescence. Scientists now understand why.
A chemical in the brain called dopamine is responsible for the feeling of pleasure. When something enjoyable happens, we experience what some scientists have called a dopamine squirt, which leads to the sensation of pleasure. It makes us want whatever elicited the squirt, because the feeling of pleasure it produces is so strong.
We now know there is a rapid increase in dopamine activity in early adolescence in fact, there is more dopamine activity in the brains reward center in early adolescence than at any other time of life. Because things feel especially pleasurable during early adolescence, young adolescents go out of their way to seek rewarding experiences. At all ages we seek out things that make us feel good, of course. But the push to do this is much more intense in early adolescence than before or after.
The urge to seek out rewarding and pleasurable experiences is a mixed blessing. On the plus side, its part of what makes it so much fun to be a teenager. But sometimes this drive is so intense adolescents can exhibit a sort of reward tunnel vision. They are so driven to seek pleasure they may not pay attention to the associated risks. To a teenager, the anticipation of driving fast can feel so good thoughts about a speeding ticket (or worse) dont even make it onto the radar.
This combination of advanced (but not yet mature) reasoning and heightened sensation seeking explains why otherwise-intelligent adolescents often do things that are surprisingly foolish (like driving 100 miles an hour just to see what it feels like). More important, the fact that teens ability to control impulses is immature just when interest in sensation seeking is stronger than ever makes them vulnerable to making mistakes.
Graduated driving laws have been successful in part because they prevent teen drivers from putting themselves in situations that exacerbate their vulnerability to risk taking. In our own research, we have found the mere presence of friends elevates risky decision-making among teenagers, but has no such impact on adults. We have shown this effect is due to the impact friends have on the adolescent brains reward system. When friends are around, this system is more easily aroused, and teens then pay more attention to the potential rewards of a risky decision than to the potential costs. This helps explain why rates of automobile crashes among teen drivers are so much higher when they have passengers than when they are driving alone. And it reaffirms how important it is for you and your adolescent to have an ongoing conversation about the importance of putting the brakes on thrill-seeking when he or she is behind the wheel. Tell them to save that for roller coasters.
Laurence Steinberg is the Distinguished University Professor of Psychology at Temple University and the author of You and Your Adolescent: The Essential Guide for Ages 10 to 25.