Think adolescence is over by 18 or even 25? Fresh research reported by BBC News reveals our brains keep their adolescent rewiring mode until about age 32, then shift into a long, steady phase that lasts through midlife. Using brain scans from around 4,000 people aged up to 90, University of Cambridge scientists mapped five distinct life phases with key turning points at 9, 32, 66, and 83.
Childhood gives way to a ruthless efficiency upgrade starting at 9. The brain then peaks for efficiency in the early thirties, settles into three decades of stability from 32 to 66, and gradually becomes more region‑focused in later years.
What makes this truly noteworthy is the length and significance of the adolescent window. It runs from 9 to 32 and is the brain’s only period where neural networks become more efficient. That helps explain why mental health conditions often emerge in the teens and twenties, and why so many people describe their early thirties as a moment of clarity and capability.
For women over 35, the message is reassuring. From the thirties through the mid‑sixties, the brain is in its longest stable phase, which aligns with a plateau in intelligence and personality. Early ageing, beginning around 66, is not an abrupt decline. The brain shifts toward tighter local teamwork among regions rather than falling off a cliff.
The study did not analyze women and men separately, which means important questions remain. The researchers note menopause is a key area for future investigation, and every brain is unique, so these are population patterns rather than fixed rules.
Still, the clarity of those milestone ages gives a fresh framework for understanding our own cognitive seasons. It offers parents, caregivers, and especially midlife women a science‑backed lens for planning mental wellness, lifestyle choices, and expectations across decades.
As lead author Dr Alexa Mousley told the BBC: “The brain rewires across the lifespan. It’s always strengthening and weakening connections and it’s not one steady pattern – there are fluctuations and phases of brain rewiring.”
Want the full picture and expert commentary? Read the complete BBC coverage and explore the published paper in Nature Communications.
