The Mind of a Teenager
What’s going on in the mind of a teenager? That’s a million-dollar question. If parents, teachers or doctors could figure that out, a great deal of the stress of parenting teenagers would be relieved. Teenagers sometimes do things that, to quote the famous song by Will Smith, “Parents just don’t understand.” Though some teenagers rarely step out of line, most parents of teenagers find that their teen will be unable to resist the urge to engage in certain behaviors that can be maddening. Teenagers might color their hair pink, purple or green, they might get tattoos without permission, they might get piercings, they might wear clothes that seem unusual, they might stay out past curfew and they might quit doing sports they used to love and ditch their old friends to hang out with new peer groups their parents aren’t familiar with. Teenagers might even put off homework in favor of other pursuits, or listen to loud music that might not seem like music at all to anyone born before 1995.
Why do they do all this? The million-dollar question actually does have an answer. Although no one can say exactly what is happening in the teenage brain at any one specific time, the experts at the American Academy of Adolescent and Child Psychiatry have a fairly straightforward answer: change. During adolescence, between the ages of 12 and 18, the brain goes through a radical transformation. On the way from childhood to adulthood, several things happen that can account for most of, if not all, the behaviors listed above.
The Developing Teenage Brain
The brain region responsible for emotions and instinct, called the amygdala, develops early in life; the frontal cortex, the part of the brain that is responsible for higher-order functioning such as reason, thinking things through and decision making, develops later. According to an article published in the American Journal of Psychiatry, the frontal cortex:
“… is especially important for planning appropriate behavioral responses to external and internal stimuli. It functions in close association with other regions of the brain that make up cerebral systems specifically designed for individual mental tasks.”
The frontal cortex contains an even smaller area called the prefrontal cortex, which is ultimately the control room for the entire brain. Though both the frontal and prefrontal cortex are present at a very early age, they don’t start to do their most important jobs until later in life.
The Control Center of the Brain: Reason Connecting to Emotion
The development of the brain works back to front—the back of the brain is responsible for the most basic functions, such as movement, eyesight and emotions. The front of the brain—the frontal cortex and the prefrontal cortex—enables the brain to accomplish more complex tasks. Applied skills in language, mathematics, music and motor functioning (like high-level sports skills) are all refined as the frontal cortex develops, as well as more abstract things like logical reasoning and social skills.
At around the age of 12, the connections (in physiological terms, the neurons) that run from the back of the brain to the front of the brain begin an essential process called “pruning.” Just like pruning a tree, the brain progressively ignores the unnecessary neurons, and the more important ones start to “turn on.” As the prefrontal cortex develops, so do the connections between the back of the brain and the front of the brain. These processes continue much longer than most people realize: frontal lobe development can continue into the mid-twenties, and the latest research indicates that prefrontal pruning may continue well into adulthood.
Works in Progress: Teenagers Are Still Kids
Since the latest research in brain science tells us that the brain develops from back to front, from emotion to reason, this gives parents lots of clues as to why teenagers do what they do. In fact, it’s the real answer to the million-dollar question. Many parents find themselves saying to their teenagers things like “Where was your brain?” or “What on earth were you thinking?” or “Have you lost your mind?” All of these questions are completely understandable because, the truth is, the teenage brain is not finished developing. Brain imagery shows, in real time, that when adults make decisions, their frontal cortex—the logical part of the brain—is the main brain region involved, but when teenagers make decisions, it’s the amygdala and the area around it—the emotional parts of the brain—that are most involved. This is why teenagers make decisions that, to adults, just don’t seem to make sense.
Even though they may look like adults and at times even act like adults and make decisions that seem mature, it’s important for parents to remember that teenagers are not adults. They are still children. In many ways, they need their parents just as much as they did when they were younger. It’s possible they need their parents even more, because some of the decisions teenagers need to make have big consequences that can affect the course of their lives—and they don’t even have the neurons that allow them to properly think things through in a clear, rational and logical manner. As the parent of a teenager, one way to think of it is this: because they don’t really have a fully functioning frontal cortex yet, you are their frontal cortex—the control center for their rapidly changing, constantly growing and sometimes completely baffling teenage brain.
American Academy of Adolescent and Child Psychiatry. “The Teen Brain: Behavior, Problem Solving, and Decision Making” December, 2011. http://www.aacap.org/AACAP/Families_and_Youth/Facts_for_Families/Facts_for_Families_Pages/The_Teen_Brain_Behavior_Problem_Solving_and_Decision_Making_95.aspx
 Buchsbaum, M. “Frontal Cortex Function” The American Journal of Psychiatry. December, 2004. (161;12) p 2178.
Kolb, et al. “Experience and the developing prefrontal cortex” Proceedings of The National Academy of Sciences. October, 2012. (109;2) pp 17186–17193. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3477383/
 Edmunds, Molly. “Teenage Brain Development”. How Stuff Works. http://science.howstuffworks.com/life/inside-the-mind/human-brain/teenage-brain1.htm