Teenagers are fascinating. Their opinions are always changing and yet they hold to them so fiercely. They try on new identities as easily as they try on clothes and shed them just as quickly. Their moods are often erratic—elation, anger, sullenness—all within a couple of hours. They are impulsive and can never seem to make up their minds. When they do, parents and adults are often surprised, or even shocked, by their choices. Their ideas, desires, bodies, and brains are all changing rapidly, often leaving them just as confused about themselves as we are with them.
A Bit about Brain Structure
Robert J. Hedaya, MD, Clinical Professor of Psychiatry at Georgetown University, describes the brain to his students like a double scoop ice cream cone. The cone represents the brain stem which is the most primitive part of the brain. The brain stem governs autonomic functions like breathing, alertness, blood pressure, and body temperature. The first layer of ice cream on top of the cone represents the limbic system, also known as the emotional brain. The limbic system governs hormonal control, memory, and what Hedaya explains are automatic and usually unconscious emotions. The top layer of ice cream represents the cortex. The cortex houses the brain’s thinking, conscious and planning awareness centers.
A Brain-Based Explanation for their Poor Decisions and Impulsivity?
It was previously believed that a human brain was completely developed by the age of 10, but this is not the case. Brains are still rapidly developing in young people, even through early adulthood. The frontal cortex in a teenager is not fully developed, and won’t be until the age of 25. This part of the brain governs decision making and impulse control. Although a teenager does have a functioning frontal cortex, theirs operates more slowly than an adult’s frontal cortex, because critical connections have not finished development, and because it does not yet have as much myelin, the fatty tissue or “white matter” the brain needs for full functioning. This myelin acts as a kind of insulation to the brain’s electrical wiring—the nerves that send electrical impulses for communication throughout the brain. Without enough myelin, frontal cortex communication is less efficient. This is why teens struggle with decisions and often make impulsive choices that may have negative consequences.
A Brain-Based Explanation for their Self-Absorption?
Beyond impulse control and decision making, a fully developed frontal cortex is what helps us to make the connections which allow us to have insight. And insight is that all-important gem of awareness that allows us to understand and relate to other people—to have empathy for what they may be going through. Teenagers can very often seem 100% self-involved. It takes a good bit of training to hear them regularly say, “Thank you,” and waiting for them to ask about our day or acknowledging that it’s frustrating every time we have to pick up their shoes in the hallway.
Susceptibility to Learning, Excitability and Addiction
Neurologists and other scientists examining brain functioning with the use of magnetic resonance imaging (MRI) can see how the neurons and synapses inside the brains of children and teens fire far more rapidly than inside adult brains. This rapid firing is what allows young people to be able to learn many new things very quickly. Their brains can establish new pathways and create new connections because old ones haven’t already been wired and frozen into place. This feature is also what allows young people to be more excitable by their environments; excitability is part of the chemistry of learning. But this excitability may also hold some drawbacks. Teenagers may be more at risk for addiction, even if they do not have a genetic predisposition toward addiction, and more likely to need treatment for substance abuse at some point.
Another impact on teenage behavior is that of sex hormones; testosterone in males, and estrogen in females. Until about 20 years ago, the “raging hormone” theory was considered fact, and it’s still an everyday phrase in the homes of most parents of teenagers. However, scientists are concluding that brain development in teenagers is a much more pertinent explanation for their behavior. According to Jenson and Urion, the brain is only approximately 80% developed by adolescence. The incomplete connections and lack of myelin to support those connections is the reason even the most responsible, polite, honor roll teenager will jump into the pool with her iPhone by accident or rear end a police officer at a red light because she was looking at her replacement iPhone. As parents, we want to teach our kids to be accountable for their behavior, and we’re not willing to let them off the hook for extremely poor decisions like drinking and driving, but it is good to know that their behavior is probably on target with their development. Being involved in our teens’ lives, communicating with them consistently and modeling appropriate behaviors – along with displaying a great deal of patience – is the best way to assist in our teens’ maturation pr