Positive Psychology Could Help Young Adults Build Lifelong Resilience During a Period of Brain Change

Bryony Shaw, a chartered psychologist and Associate Fellow of the British Psychological Society, begins from a reversal of an old assumption. Scientists once treated brain development as a feature of childhood. Brain scanning now suggests that neural maturation continues until around age 25, and that older teenagers and young adults go through one of the most significant reorganizations of a human life.

Shaw has set out her argument in a new book, How to Raise Resilient Older Teens and Young Adults. She says this period is often turbulent for emotions, in part because the biology coincides with the demands of higher education, early employment, relationships and growing independence. But she argues the same flux that makes it hard also makes it a chance to build resilience.

She points to two regions of the brain. The amygdala is the reactive, emotional alarm system. The prefrontal cortex handles reasoning, planning and impulse control. In early adolescence the amygdala matures faster, so emotional reactions run with relatively little rational oversight. Shaw links that to the risk-taking and impulsivity typical of the teenage years. Through the late teens and into the twenties the prefrontal cortex catches up. The amygdala may still sound the alarm, but the prefrontal cortex increasingly judges whether the threat is real or false.

Alongside this runs neuroplasticity, the brain reorganizing itself in response to experience. Shaw describes how neurons that are no longer used die back through synaptic pruning, which reduces grey matter. Meanwhile myelin, the white matter, increases, and communication between the remaining neurons becomes faster and more efficient. One result, she says, is that emerging adults can learn new concepts more easily than they could when younger. In her framing, anxious thinking and self-criticism are not fixed traits but well-worn neural grooves that deliberate effort can re-route. Stop using a pathway, such as negative self-talk, and it can die off through pruning.

The context she describes is difficult. Shaw lists the cost-of-living crisis, climate change, academic demands, social media and AI as pressures on this generation. She calls the combination a polycrisis, in which overlapping crises interact and amplify one another, and says today's emerging adults live in a time where uncertainty is the norm. NHS studies show that in 2017, 10% of 17-to-19-year-olds in the UK had a probable mental health disorder, a figure that rose to 23% by 2023. The same study found 21.7% of those aged 20 to 25 had a probable disorder. The long-standing pattern in which younger adults reported being happier than the middle-aged has reversed.

Shaw's response is positive psychology, which she describes as a scientifically grounded approach that draws on neuroplasticity. Researchers study people who excel, who overcome adversity and who live with meaning and purpose, then turn the factors they find into practical, often simple activities. The tools she names are gratitude practices, self-compassion, spotting and using personal strengths, identifying values, and deliberate kindness to others. Because the brain at this age responds strongly to repeated experience, she says, these exercises can build a foundation that lasts.

She concedes the tasks are simple but not easy. Humans carry a negativity bias, an evolutionary habit of anticipating problems so they can be dealt with before they become dangerous. The side effect is that we notice what worries us before we notice what is good. Shaw adds that people tend to assume anything truly beneficial must be arduous, and so overlook easy, evidence-based practices.

She stresses that positive psychology is not positive thinking. It means using backed activities both when things are going well and when they are not. Cultivating positive emotions, she says, strengthens coping skills and dampens the stress response, helping people see situations more clearly and respond constructively. She also suggests helping young people value uncertainty, since the anxiety it causes can be followed by joy.

The piece does not detail the evidence behind these interventions, so how well they work for young adults at scale remains the open question.