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The brain is the last human organ to develop fully, which helps to explain teenagers’ bad behaviour. Photo: Alamy

Understanding the teenage brain: how parents can avoid arguments and temper tantrums

  • The brain is the last human organ to develop fully, which explains why adolescents regularly seem to act erratically and unreasonably
  • As their brains try to keep up with the rest of their bodies, it’s only natural they are a ‘tinderbox of emotions’

The brain is the last human organ to develop fully, but only recently has science established that it isn’t fully grown until a person reaches about 30 years of age.

This helps to explain why behaviour during the teenage years – when an adolescent body is also exploding with hormonal changes – may sometimes be erratic, apparently unreasonable and often frustrating. The fact is their brains are trying to keep up with the rest of their bodies.

Philip Watkins, an Australian-trained, Hong Kong-based naturopath, with more than a decade of clinical practice treating clients of all ages, explains the cerebral changes during what has been called a time of “tinderbox emotions”.

The brain evolves both structurally and functionally during adolescence, he says. During this time, “synaptic pruning” occurs, a process in which connections in the brain that are used often are strengthened through repetition, and connections that aren’t used so much are weakened.

Adolescents regularly seem to act erratically and unreasonably, infuriating their parents. Photo: Alamy

US-trained, Hong Kong-based clinical psychologist Dr Kimberley Carder elaborates: “During neurological pruning, the brain sheds unnecessary neural pathways and strengthens those which are important. Grey matter thins out and white matter takes over, starting from the back of the brain and finishing at the front.

“This process happens faster with girls than with boys. The parts of the brain that allow yourself to see something from someone else’s point of view are still being processed.”

This may well explain some of the parent-teen clashes over what one thinks is acceptable in terms of behaviour, attire and plans. What parent has not argued with adolescent children about whether what they are wearing is suitable?

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The prefrontal cortex is the last region of the brain to mature, but it is also the area of the brain that controls reasoning and helps us think before we act. For this reason, Carder says reasoning with a teenager by urging long-term thinking is often a waste of time.

When asking an adolescent about the consequences of their actions it is hard for them to understand. Teenagers are more prone to making decisions that are governed by the way they feel as opposed to what adults may deem rational, says Watkins.

Although the prefrontal cortex is still figuring itself out, Carder says, other areas of the brain develop much earlier, areas like the “reward centre”, the nucleus accumbens, and the “fear, aggression and emotional centre”, the amygdala. A Cornell University study found that teenagers demonstrate the largest activation in the nucleus accumbens to rewards when compared to children and adults.

Philip Watkins is an Australian-trained, Hong Kong-based naturopath.

Teenagers are more stimulated by large immediate rewards than long-term gain, which explains why they’re on the lookout for pleasure-seeking activities much more than children and adults. Teenagers, she says, “are literally wired for risk-taking behaviours”.

It’s this disparity in development that accounts for lots of drama and little direction: teens cannot help being reactionary and overemotional, are unavoidably prone to risk-taking, and often struggle to understand the consequences of their choices as they lack the ability to “think ahead”.

No wonder this window in brain development has been compared to driving a powerful sports car with shaky steering and poor brakes.

The parts of the brain that allow yourself to see something from someone else’s point of view are still being processed in teenagers
Dr Kimberley Carder

It’s important not to be too hard on teens. When grown-ups regard them in a negative light, this enforces the negative stigma that they are just being difficult. Watkins says that it’s not just that teen brains haven’t caught up with the grown-ups’ yet. They simply use their brains differently because of the ongoing development of specific regions.

This is why teens are also at their most reactionary and sensitive. The medial prefrontal cortex is the area of the brain that relates to self-consciousness, he says, and has been shown to peak during adolescence, which might explain why teenagers can be particularly sensitive to what they may see as criticism, for example.

Behaviour literally rewires the brain, Carder stresses. The more we do something, the stronger that neural pathway becomes.

Teenagers’ brains are wired for risk and pleasure. Photo: Alamy

“Neurons that fire together wire together. Therefore encouraging pro-social behaviours teaches the brain to scan the environment for things that they appreciate,” Carder says.

And when it goes wrong, she says, and it will, and your teen does something you deem stupid, do not flare up. Count to 10 and ask why they acted in that particular way. Question with curiosity, not sarcasm. Then ask, given a possibly less-than-perfect outcome, what they might do differently next time.

She endorses the fact that raising teens safely, given they are “wired for risk and pleasure”, but lack the experience to make the right decisions, can be a daunting task for any parent.

They have to make their own mistakes to ensure success for the future, she says, but they need this to happen in a safe environment “where reflection and introspection are scaffolded by parents or adults”.

Taking risks is what teenagers do. They cannot help being reactionary because of how their brains are wired. Photo: Alamy

In this sensitive period of development, teen brains are most vulnerable. Yet it is precisely during this time that teens are more likely to expose themselves, and their grey matter, to harmful substances as they experiment.

Cannabis, alcohol and nicotine have all been shown to potentially have enduring harmful effects on a developing brain. Cannabis can hinder IQ and predispose a young user to mood disorders.

The Centres for Disease Control in the United States notes that nicotine – which reaches the brain very quickly, within 10 seconds of inhalation – stimulates the reward centres of the brain equally fast, triggering the release of dopamine and adrenaline, and that can set the stage for lifelong struggles with addiction.

The message is to understand that teens really often cannot help their behaviour, so be prepared to help them.

US-trained, Hong Kong-based clinical psychologist Dr Kimberley Carder.

How grown-ups can support teens as their brains mature

Adolescent brains, says Philip Watkins, are much faster and more efficient at learning than adult brains – a consequence of the younger brains’ transient and heightened “sensitivity to reward”.

This exacerbates their risk taking, “especially around their friends.” So directing them towards healthy risk taking, he advises, such as joining a sports team, can be a good way to encourage the natural risk-taking tendencies teenagers exhibit.

This can also give parents the opportunity to positively reinforce their teens’ behaviour but also support them when the risk does not end in any reward.

Teens look for guidance as their independence broadens, so he encourages parents to be a positive role model for them.

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“‘Be the change you want to see in the world’ might be an appropriate mantra,” he says. Your child will learn from how you interact with friends, partners and family members, especially relationships that encourage empathy and respect.

Most importantly, he says, listen.

“If your teenager wants to talk, give them your full attention, and if you cannot at the time, make a specific time when you can,” Watkins says. “If your relationship is struggling, then it might be a good time to organise some counselling so that your child can feel safe in expressing how they feel on a regular basis.

“There’s also the added benefit of experiencing the reward of talking something through and the clarity it can offer in the end.”

This article appeared in the South China Morning Post print edition as: Why it’s not easy to fathom how teenagers think