The Science of the Teenage Brain

The Legacy of Perplexing Teenagers

Today's teens turn their parents' hair gray by texting while driving, experimenting with drugs or dating a middle school dropout. Yet this behavior that may seem reckless at best and downright life-threatening at worst is not unique to American teens, or even to the modern era. More than 2,000 years ago, Aristotle commented that 'the young are heated by Nature as drunken men by wine.'

The peculiar actions of teens, including a heightened passion for excitement and risk, is found throughout the world. While culture may play a role in how the behavior manifests itself, parents in India, Iceland, Brazil and Japan are just as frustrated as parents in the United States. The teen form a rural farming community in China may not get arrested for driving 100 miles per hour while intoxicated, but he surely finds his own way to baffle his parents.

Inside the Teenage Brain

As reported recently in National Geographic, there are biological explanations for why teenagers act as they do. The brain is 90% grown by age six, but a tremendous reorganization occurs between ages 12 and 25. For example, white matter in the brian known as myelin begins to insulate the axons, which are the nerve fibers that conduct signals between neurons. Also, the hippocampus develops a stronger link with the frontal areas of the brain; this fosters better integration between memories and decision-making.

All of this developmental activity naturally comes with kinks that must be worked out. It takes the brain years to line up its newfound skills with thoughtful intent and caution. Essentially, the brain quickly gains adult powers but, like Spider-Man or other comic book heroes, it must learn how to use them responsibly. This cognitive complexity and confusion also explains the erratic nature of teen behavior; the brain is figuring itself out and that inherently causes inconsistency.

The Upside of Confounding Behavior

Teenagers drive their parents crazy. That may be an inescapable fact. But research suggests that teenage behavior that's linked to adolescent development is actually a form of natural selection. The light at the end of the tunnel for a parent struggling to deal with a problematic teen is that the teen is approaching an age when he or she will hopefully leave home. As it turns out, the frustrating behavior of teens is the brain's way of preparing them for this looming independence.

An example of this is impulsive behavior, which peaks at age 15. Impulsivity manifests itself in teens driving too fast or trying to skateboard down a flight of steps. But it also causes teens to want to meet new people and try new things. While the skateboarder tumbling down the stairs is the more newsworthy impulsive behavior, the widening circle of friends and interests leads to improved health, happiness and success. The same behaviors that appear purposeless are often helping teens evolve and prepare to be highly functioning and independent adults.