Inside the Teenage Brain: Adolescent Development in the Classroom

by Terence J Houlihan, MS Ed

Discover the science behind teenage behavior.

You know the student: She sighs, rolls her eyes, and shrugs her shoulders all at the same time to show her displeasure with your classroom management techniques. Or he may put his head down on his desk in the midst of what you deem to be the most powerful part of the lesson.

The student has not been diagnosed as ADHD, oppositional, ADD, etc. The student does not have a learning disability. The student is an adolescent. A typical one for that matter.

The same students described above could act very differently on a different day of the week. They might be focused, engaged, respectful, compliant, energetic, etc. And for many who work closely with adolescents, they know that these ranges in behaviors are quite normal.

In the last 20 or so years, the field of adolescent brain development research has gained momentum. PBS created a series called Inside the Teenage Brain in 2002 that received national attention. More recently, the October 2011 issue of National Geographic Magazine included a feature on the teenage brain. Across the nation, school systems are considering later start times because of sleep studies showing that teens need more sleep.

However, as adolescents move from elementary school to middle school and to high school, there are adults who expect them to automatically make mature decisions, as if the sheer process of development magically grants adolescents adult-like thinking skills. This is a recipe for future conflict. Teachers become disappointed, and young adolescents feel misunderstood. What these adults don’t know is that teens process information and make decisions differently than adults.

In order to get a better understanding of this, let’s take a look inside the head of an adolescent.

The Prefrontal Cortex

Before most children reach middle school, their brains have reached their size potential. At the onset of adolescence (about 11 or 12), another type of growth spurt occurs: strengthening of nerve cell connections. This process continues until the mid-20s, although some new research suggests that this process can continue until the 30s. The adolescent brain is fine-tuning its network, which will allow tweens and teens to respond faster and less emotionally.

Imagine the United States prior to the building of interstate highways. In 1919, it took President Eisenhower (then a lieutenant colonel in the Army) and a convoy of other soldiers 62 days to drive from Gettysburg to San Francisco, with a few stops and speeches along the way. Today, one can drive from Teaneck, NJ, to San Francisco along I-80 in 3 to 5 days. Similarly, both the adolescent and adult brains are like the landmass of the U.S., wherein the adult’s brain has all of its connections built but the adolescent’s doesn’t. Teens are often expected to arrive at the same destination at the same time as adults, but without those upgraded “roads.”

The last part of the brain to develop is the prefrontal cortex, located behind the forehead. This is the part of the brain responsible for executive skills. Some examples of executive skills are time management, organization, short-term memory, goal setting and initiation, and self-restraint. As mentioned, these skills are not mastered until the second or third decade. Even though some teachers will become frustrated with the adolescent who forgets to hand in homework or misses parts of the quarter project or responds unkindly to a question, the problem is often one of brain capacity rather than laziness or thoughtlessness.


If a developing prefrontal cortex isn’t enough to frustrate a teacher on a Monday morning, young people are also going through astronomical hormonal changes. Specifically, adolescent males are producing 20 times the amount of testosterone that they had in their bodies when they were in elementary school. Testosterone has been shown to increase aggression and decrease the desire to talk and connect socially. This could account for some of the male behavior seen in classrooms, locker rooms, and hallways. Female teenagers will experience surges of estrogen during which they may feel especially confident and energetic. Estrogen also releases oxytocin, a hormone which will increase their desire for intimate connections. (Did you ever wonder why most of your chatterboxes were girls?)

Males also produce another hormone called vasopressin, which has been shown to affect the way teenage boys read facial expressions. When vasopressin and testosterone are combined, the stress hormone, cortisol, kicks in. So, if a teacher calls on a seventh-grade boy who doesn’t have his homework complete, these three hormones will flood his brain (and with an already underdeveloped prefrontal cortex) and he might respond in a regrettable manner. Towards the latter part of the menstrual cycle, when progesterone kicks in, the teenage girl will experience a shift from the energizing influence of estrogen to progesterone irritability.


Nature has decided to have a little bit more fun with us by making teenagers’ sleep cycles go through a radical shift. When estrogen (for girls) and testosterone (for boys) reach higher levels, their “fall asleep” time usually drops back by about two hours. While in the early part of elementary school students might have been nodding off by 9 or 10 p.m., now their brains may not let them fall asleep until 11 or 12. The National Sleep Foundation recommends that adolescents get at least nine hours of sleep to experience optimal performance during the day. With many school start times around 7 a.m., middle-school students are in what one researcher refers to as a continuous state of jet lag.

When comparing brain scans of adolescents who are sleep deprived and those with ADHD, the results are strikingly similar. Over time, as adolescents are chronically sleep deprived, the connections between the emotional part of their brain and the prefrontal cortex suffer, adding to their already moody dispositions.

Some school systems have heeded the research and initiated later start times. In Minnesota, Kentucky, and Rhode Island, the results are noteworthy. After altering the school day to begin around 8:30 a.m., educators witnessed decreased absences, improved grades, fewer school nurse visits, and fewer suspensions. The students in those schools reported feeling more alert and happy.

Tying It All Together

The picture painted may scare off anyone considering entering elementary, middle, or high-school education. However, as more educators use this information to inform their curricula, classroom management, and school policy, students, teachers, administrators, and parents will all benefit.
As mentioned, the adolescent brain is a work in process. Again, adolescents have not mastered their executive functioning: time management, organization, task initiation, etc. When teachers infuse study skills, scheduling, organization, and goal setting into their lessons, students will become more adept at these skills. It is important to note that at many colleges and early college high schools, students are required to take classes in study skills, organization, and time management: skills that are known to bolster academic success.

Also, teaching students about the benefits of healthy sleep habits in a manner that allows them to see the results of a good night’s sleep can be more beneficial than pointing out just how tired they are in class, or leaving those responsibilities to the physical education instructor.

Teachers can also impart information about the following to students in a developmentally appropriate manner:
• their developing brains and bodies
• how specific hormones affect emotions and thinking
• de-escalation techniques in conflicts
• how to communicate more effectively

When it comes to classroom management, the operative term is de-escalation. Rather than focusing the spotlight on the young adolescent who’s acting out in front of 25-30 classmates, the teacher should talk with that student outside of class, where he or she is less likely to experience resistance from the student. Teachers who are educated in the developing executive skills of adolescents have reported that they will write a homework assignment on the board, say it aloud, ask students to write it in their agendas, and (if available) post the homework on the school’s website. These teachers see more positive academic results, and their students indicate that these classes are easier to manage because they are aware of the expectations and feel more confident in their ability to manage the workload.

Because of the strong community support surrounding Catholic schools, teachers are in unique positions to affect profound change for developing adolescents. When students feel understood and supported by their teachers (and their caregivers), it is safer for them to exercise their creative spirits and excel in the classroom.

Source: Today’s Catholic Teacher, October 2014