The Teen Brain

Can I just tell you how much I love teenagers?  I am student teaching at a high school and I thoroughly enjoy being around these young people, with their varied personalities, interests, challenges, goals, etc..  I obviously adore science, but these kids make my job so great I'd probably still like it even if I didn't get to teach about my favorite thing ever. I just wish they all knew how awesome they are and can be.

Adolescence is a really interesting conundrum in the development of a human being.  It's an exciting time that leads up to so many big life changes- getting through school, choosing a career, starting a family, making a place for oneself in the world.  So many physical changes are happening, not the least of which are the changes in the brain.  These changes make it both easier and more difficult for people to become responsible adults, which is one reason it is so incredibly fascinating, and makes me truly appreciate and empathize with teenagers that much more.

An explosion of brain development
It is well-known that humans go through an explosion of brain development during the first 3 years of life.  Infants and toddlers are actively exploring their worlds and making many connections in their brains.  But did you know this explosion also happens in adolescence?  And interestingly, an important part of this development is cutting away parts that are no longer needed.  This process is called "synaptic pruning".

Synaptic Pruning
This term refers to the "synapses" which are the connections between brain cells.  Cutting those away may seem counter-intuitive, but it is actually a wonderful part of developing a faster, more efficient brain.  It's a very exciting time for learning.
Here are some photographs taken through a microscope of brain cells at various ages.  Notice how there is an explosion of growth as the baby develops, and then as they become school-aged, things are pruned away while what's left becomes strengthened.

I have put in a couple of great video clips to explain this process.

Short, student-friendly explanation:



More detailed (fascinating!) info on synaptic pruning - TED talk by Sarah-Jayne Blakemore:




Prefrontal Cortex Development
If you watched that second video above, you heard a lot about how the adolescent prefrontal cortex is developing.  This area of the brain is very important for higher-order or "executive" functioning skills.  That includes things like planning, predicting consequences, impulse control, and personality.

So the interesting thing is.... this area of the brain is not fully developed in humans until around age 25!  Does the sometimes irrational behavior of teenagers make more sense given that information?  Teens are very prone to risk-taking, which makes sense given the fact that they are still learning how to control impulses, predict consequences, and make good decisions.  This lower impulse control can also be an amazingly good thing!  So many people have made amazing discoveries, inventions, etc. while in this stage of brain development, because they had all the drive to go for their goal, without their brains putting the brakes on.  So while impulse control is super important, sometimes it can be overdone and stifle creativity.  Without that fully in place, teens can do some amazing things - amazingly stupid or amazingly creative and exceptional!


Societal influences
So the conundrum I mentioned is that a teenager has this amazing brain with abilities and creativity, but heightened propensity toward risk taking and foolishness and less ability to control those impulses.  And yet this is a time period when people are expected to make really important decisions that will shape the rest of their lives.

It is also a time when many young people are filling those moldable brains of theirs with garbage!  Not just garbage that will prove pretty useless in the future, like Angry Birds and Candy Crush.  But garbage that is going to forever stunt their progress and could even ruin their lives. Alcohol, pornography, and drugs can wreak havoc on a developing brain and the person whose head it's in.  But those are the things that are exciting and new, and the teen hasn't yet developed full ability to put the brakes on.

That, however is NOT an excuse.  It is important for teenagers to realize the limitations of being a teenager and rely on advice of parents, guardians, teachers, and other trusted adults to help keep them safe.  It makes perfect sense that we strive to educate young people about staying away from risky things like drugs before they even get to be teenagers.  If a young person can decide while they are a child that they will say no to drugs, no questions asked...that choice has already been made and they won't have to grapple as hard with it later on.  They will also be helped by the added protection of choosing good friends who have also made similar choices for themselves.

So to wrap this up.... teenagers are awesome creatures.  They have a LOT of brain work to do, while working with a less developed instrument than those of adults.  They need good adults who will support and guide them.  Do what you can to help educate them, but above all, love them and cut them a little slack.