For a long time, scientists thought that brain development was an exclusive feature of childhood, but now we understand that the brains of older teenagers and young adults undergo one of the most remarkable reorganisations in human lifetime.
Combined with the challenges in navigating higher education, early employment, relationships and increasing independence, it can be a turbulent time for emotions.
But Chartered Psychologist (CPsychol) and Associate Fellow (AFBPsS) of the British Psychological Society Bryony Shaw tells us while this period of neurological flux may be a source of struggle, it can also be the key to resilience. She suggests positive psychology can harness the brain’s extraordinary potential to rewire thinking, transform habits and lay the foundations for lifelong resilience and wellbeing.
“We can all learn how to deal with the challenges life throws at us, without becoming overwhelmed. We can all learn how to thrive in challenging situations,” she explains.
“You can help them to value uncertainty, as often the anxiety caused in times of uncertainty times, can be followed by joy.”
Pressures on young adults today
In her new book, How to Raise Resilient Older Teens and Young Adults , Shaw explains there are unique and specific challenges facing this generation, such as the cost-of-living crisis, climate change, academic demands, the pressures of social media and AI.
“All generations live through times of uncertainty; it may be a world war, a global economic downturn, climate change or technological revolutions. However, today’s emerging adults are living in a time where uncertainty is the norm; they are navigating a polycrisis. This is where a number of overlapping crises occur at the same time and interact with each other, amplifying their destructive impact,” she explains.
NHS studies showed that in the UK in 2017 10% of 17–19-year-olds experienced a probable mental health disorder and this rose to 23% by 2023. The same NHS study also showed 21.7% of people aged 20-25 also experienced a probably mental health disorder. The typical wellbeing trend that has for years shown younger adults being happier than middle aged adults, has now reversed.
But Shaw says that while poor mental health is on the rise, there is also a great deal of hope.
“The good news is that a lot of the factors involved in emotional resilience are skills and mindsets, which are within our control and we can develop them if we do not already possess them,” she explains.
A brain under construction
Shaw explains the unique brain science behind this often-tumultuous life period.
Contrary to previous assumptions, brain scanning studies show that neural maturation, or brain growth, continues until around the age of 25. Two regions in particular undergo a shift in balance of power during early adulthood: the amygdala (the brain’s reactive, emotional alarm system), and the prefrontal cortex (the seat of reasoning, planning and impulse control).
In early adolescence, the amygdala matures faster than the prefrontal cortex. This means emotional reactivity is relatively unchecked by rational oversight, which explains the risk-taking and impulsivity characteristic of teenage years.
But as young people move through their late teens and into their twenties, the prefrontal cortex catches up, bringing emotional responses into context. The amygdala may still sound the alarm, but the prefrontal cortex increasingly decides whether that alarm reflects a real threat or a false one.
This changing balance, Shaw argues, presents a window of opportunity.
While young adult brains are busy trying to impose logic, there’s another vital process underway – neuroplasticity: the brain reorganising itself in response to experience.
“As adolescence progresses and the stage of emerging adulthood is entered, neurons that are no longer used die back through a process known as synaptic pruning. This reduces the amount of grey matter. At the same time, the amount of myelin, white matter, increases and communication between the remaining neurons speeds up and becomes more efficient. This can result in emerging adults being able to learn new concepts more easily than they did when they were younger,” she explains.
This means that patterns of anxious thinking or self-criticism are not fixed traits, but the result of well-worn neural groove that can, with deliberate effort, be re-routed.
“This is a wonderful gift as it gives us the ability to intentionally unlock our brain’s potential to enhance our wellbeing, improve resilience and become the best version of ourselves.
“We can also overcome ways of behaving and thinking that do not serve us well, such as negative self-talk and procrastination. By intentionally stopping negative self-talk we will not be using those neural pathways and they will die off through synaptic pruning,” she explains.
Why positive psychology?
Positive psychology is a scientifically grounded intervention that harnesses the power of neuroplasticity.
“Researchers study people who excel in their field, who triumph over adversity and who live lives full of meaning and purpose, in order to discover what factors are involved in flourishing. The researchers then convert these factors into practical and often simple activities which enhance wellbeing,” Shaw explains.
These empirically-backed tools include gratitude practices, self-compassion, spotting and using strengths, identifying values, and deliberate kindness to others. Because the adolescent and emerging adult brain is especially responsive to repeated experience, these exercises create a resilient foundation for life.
Shaw acknowledges that although the tasks are simple, they are not easy to do, as human brains carry a built-in negativity bias. This evolutionary hangover primes us to overlook simple, evidence-based wellbeing practices, precisely because they’re easy. Humans are essentially hard-wired to assume that anything genuinely beneficial must be arduous.
“Our negativity bias is a way of looking at the world that anticipates problems and difficulties. This is so that we can spot them easily and deal with them before they become a danger to us. However, it means that we notice difficulties and things that worry or scare us before we notice the good things. Our negativity bias means that we often unintentionally ignore the easy and good things in life.”
Rewiring brains for resilience
The message is that resilience itself is trainable through repeated, intentional engagement with wellbeing-boosting activities. Given that brain plasticity is at a developmental peak during the late teens and early twenties, this period represents a unique moment for building these habits.
“Positive psychology is not about positive thinking. It’s about developing and using scientifically backed activities to enhance our lives. We can use these activities when we’re doing well in order to do even better. We can also use them when we are struggling as a result of life’s challenges,” she explains.
“By cultivating positive emotions we are enhancing our coping skills so we can dampen down our stress response. This will help us see situations more clearly and respond in a constructive way.”