Inside the teenage brain

May 13, 2021

Adolescence is truly a remarkable time of innovation and development, yet people are more likely to describe teenagers as awkward, lazy, or excessively reckless. Why is this? How is the most innovative chapter of human development enshrouded by moodiness and angst? What is governing the behaviour of teenagers???

Grab a cuppa, get yourself comfy, and let me take you on a journey into the teenage brain…

All throughout early childhood our brains learn at an amazing rate, synapses are firing data to each other faster than anything an adult can comprehend- even faster than a super computer! Although physically our brains are 90-95% full-sized by the time we are six years old, the connections inside are under construction and steadily growing until we hit puberty around 10-13ish. The brain then undergoes a massive reconstruction and remodelling process which continues until mid-twenties- if you are under the age of 25 the chances are that your brain is still finalising some of its wirings. We have these little neurons called synapses inside our brain which are like electric muscles, the more the different parts get used, the stronger they become. At the same time our clever brains are engaging in this thing called pruning where they get rid of all the bits that aren’t being used (known as grey matter) this is the brain’s way of becoming more efficient, based on the ‘use it or lose it’ principle- that’s why it is so important to practise things we want to be good at!

15ish years is a very long time of renovation, but at the end of it we come out with a stronger, and more sophisticated brain. A complete upgrade.

Our upgrade is run by chemical changes called hormones. Hormones effect the entire body, and increase by up to 50% during puberty. They are key in deciding things like where you grow hair, what turns you on, and your moment by moment mood. They strengthen bone and muscle and skin, as well as keep your heart beating, your body hydrated, and make your organs grow and develop… But that’s not all- not only are they busy making loads of physical changes to our bodies, the huge increase of sex hormones (testosterone and oestrogen) create brand new feelings. These new emotions often look and feel like moodiness, anger, depression, even a ‘zombie like fog’. Then to add to this influx of hormones most teens are also suffering from lack of sleep.

Adults have the great ability to make decisions and choices based on logic, which is reached through a weighing up of potential consequences. This happens in a part of the brain called the prefrontal cortex, which is right at the front behind your forehead. It controls impulses and emotions and the forming of judgements. Actually all these things are formed and stored in other parts of the brain but run through the prefrontal cortex before travelling out of the brain and becoming an action – so your prefrontal cortex is kind of like a buffer to decide what to do with any information, like a logical processing unit. The thing about teenagers is that their brains don’t quite work like this yet… remember the pruning overhaul renovation and reconstruction I talked about earlier: it starts at the back and works its way forwards. The back of the brain is where you find the more fundamental parts, working forwards through to the more complex areas (see Figure 1). Therefore the prefrontal cortex, in the frontal lobe is literally the last place to get the ‘adult upgrade,’ concentration, planning, and problem solving are usually being finalised into your mid-twenties. Until then situations are responded to via our amygdala, which runs entirely on gut reaction, instinct, and aggression- with absolutely zero impulse control, logic, or weighing up of consequences. This reactionary impulsive response leads to more risk taking behaviours, which is why teenagers are more likely to experiment with extreme sports, drinking, drugs, sex etc. It is important to note that the still developing brain is also at its most vulnerable to lasting effects: studies suggest that the teenage brain is more vulnerable to addictions. This is because their brains are more in tune with their reward centre, which again is towards the back of the brain so the pleasure and reward zone develops before the rational consequence thinking part.

So to summarise that all into one sentence- teenagers aren’t lazy or making intentionally stupid decisions- their brains are literally finishing being built

Teenagers can’t think forwards in time, so don’t expect them to; this is not something we can change, but what we can do is maintain our relationship with them regardless of stupid decisions or risky behaviours, we can work to keep communication lines open and be a safe space for them be themselves around us.

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If you are a parent, here are some helpful suggestions which might encourage healthy behaviour and strengthen positive brain connections:

-Encourage your child to take some healthy risks. New and different experiences will help them develop an independent identity, explore grown-up behaviour, and move towards independence.

-Help your child find new creative and expressive outlets for their feelings and emotions. E.g. playing or watching sport, music, writing, dancing and other art forms.

-Talk through decisions step by step with your child. Ask about possible courses of action your child might choose, and talk through potential consequences. Encourage your child to weigh up positive consequences or rewards against negative ones.

-Use family routines to give your child’s life some structure. These might be based around school and family timetables.

-Provide boundaries and opportunities for negotiating those boundaries. Young people need guidance and limit-setting from their parents and other adults.

-Offer frequent praise and positive rewards for desired behaviour. This reinforces pathways in your child’s brain.

-Be a positive role model. Your behaviour will show your child the behaviour you expect.

-Stay connected with your child. You’ll probably want to keep an eye on your child’s activities and friends. Being open and approachable can help you with this.

-Talk with your child about their developing brain. Understanding this important period of growth might help your child process their feelings. It might also make taking care of the brain more interesting for your child.

Although physically our brains are 90-95% full-sized by the time we are six years old, the connections inside are under construction and steadily growing until we hit puberty around 10-13ish. The brain then undergoes a massive reconstruction and remodelling process which continues until mid-twenties- if you are under the age of 25 the chances are that your brain is still finalising some of its wirings. We have these little neurons called synapses inside our brain which are like electric muscles, the more the different parts get used, the stronger they become. At the same time our clever brains are engaging in this thing called pruning where they get rid of all the bits that aren’t being used (known as grey matter) this is the brain’s way of becoming more efficient, based on the ‘use it or lose it’ principle- that’s why it is so important to practise things we want to be good at!