If he’s said it once, he’s said it a thousand times: “It seemed like a good idea at the time.” The kid is sixteen. Isn’t he old enough now to understand the consequences of his actions? Perhaps not.

Scientists now say adolescent brains are not like adult brains. Testing shows that an adolescent’s brain will continue to develop well into adulthood. The pre-frontal cortex, the part of the brain that controls emotions, impulses, and planning, is the last part to develop completely and connect to the rest of the brain. This information may evoke an “aha” response from parents of teenagers who disregard rules, break promises, or even sneak out of the house late at night.

The adolescent brain doesn’t have as much of the nerve covering myelin, which makes nerve signals flow smoothly and quickly within the brain. As a result, teens do not immediately understand the consequences of their actions. The typical parent to teen question, “Don’t you ever think about what will happen if you do such and such,” now becomes a bit murky. The teenager might not yet be able to think things through.

The brain chemistry of a young brain is also different in that it allows young people to learn more quickly than adults. This might be useful in the acquisition of academic subject matter. Unfortunately, this fast learning process also includes learning to like and crave drugs and alcohol.

One area of the teen brain that works overtime is the nucleus accumbens, which seeks pleasure and reward. Daredevil stunts may be a result of this need for an excitement buzz. Add the emotional roller coaster caused by fluctuating hormones, and it is little wonder teens can behave erratically.

Does this knowledge help parents? One implication is that teens are four times more likely as adults to be in a car crash due to impulsive behavior, the inability to foresee the consequences of their actions. Their brains are, in fact, not yet capable of making some very important — even life altering — decisions.