Our brains go through five major transformations in life - and it turns out, you might still be in your adolescent phase well into your thirties.
That’s what researchers at the University of Cambridge have uncovered after analyzing brain scans from nearly 4,000 people, ranging in age from birth to 90, per BBC News.
The study revealed a set of distinct stages that shape how our brains wire and rewire across the decades.
Forget the idea that brain development ends with your teenage years. According to the data, the real peak doesn't come until later in life.
The five life stages your brain goes through
The study - published in Nature Communications - found that brain changes don’t follow a smooth, gradual curve. Instead, the brain reshapes itself in phases, with sharp shifts at specific ages:
- Childhood: Birth to age 9
- Adolescence: Ages 9 to 32
- Adulthood: Ages 32 to 66
- Early ageing: Ages 66 to 83
- Late ageing: 83 and older
Lead researcher Dr Alexa Mousley explained: "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."
Thanks to the massive scale of the brain scan dataset, researchers were able to clearly pinpoint these transition ages.
Researchers have been studying the brain. Credit: Andrew Brookes / Getty
So, what exactly happens in each phase?
In the earliest years, the brain is growing at lightning speed. While it’s making tons of connections - known as synapses - it’s also pruning the extras.
But don’t expect laser focus. The brain at this stage is more like a curious child wandering aimlessly through a park than someone heading directly from point A to point B.
Adolescence lasts until 32 - and it’s the brain’s most efficient phase.
At around age nine, everything shifts. The brain starts optimizing its network of connections, making it far more streamlined and efficient.
Dr Mousley called it "a huge shift," and said it marked the most dramatic transition between brain phases.
According to the brain, adulthood starts at 32. Credit: KATERYNA KON/SCIENCE PHOTO LIBRARY / Getty
This is also when the risk of developing mental health disorders is at its highest.
The timing isn’t surprising - it lines up with puberty - but what’s shocking is how long this phase lasts.
It was once thought adolescence ended with the teenage years. Then neuroscience pushed that boundary into the twenties. Now, it turns out we might still be in that phase well into our early 30s.
"It's very interesting," Dr Mousley added, "that the brain stays in the same phase between nine and 32."
It’s also the only stage where brain efficiency improves, supporting the theory that our cognitive abilities peak in the early thirties.
From age 32 to 66, the brain enters its most stable era. The fireworks of adolescence are over, and changes happen more gradually.
Dr Mousley said this period "aligns with a plateau of intelligence and personality"—something many of us can relate to.
But during these three decades, brain efficiency begins a slow decline.
At 66, the brain starts reorganizing in a new way. Instead of working as a unified system, it begins to operate in more segmented regions. Think of it like a band whose members start doing solo projects.
This phase coincides with the age when conditions like dementia and high blood pressure begin to emerge, both of which can impact brain health - even though the study focused solely on healthy brains.
The final phase sets in at age 83. While similar to early ageing, the changes are more extreme. There was less data in this group due to the difficulty of finding enough healthy older participants.
Still, what stood out to Dr Mousley was how closely the brain's transition points match up with key life milestones. "What really surprised her was how well the different 'ages align with a lot of important milestones'" - everything from puberty and health risks to major life shifts like becoming a parent.
Those under 32 can enjoy their youth a little longer. Credit: Monty Rakusen / Getty
What the experts say
Although the study didn’t break down results by gender, it raises new questions about how life events like menopause might factor into these phases.
Professor Duncan Astle, a neuroinformatics expert at the University of Cambridge who contributed to the research, explained: "Many neurodevelopmental, mental health and neurological conditions are linked to the way the brain is wired. Indeed, differences in brain wiring predict difficulties with attention, language, memory, and a whole host of different behaviours."
Meanwhile, Professor Tara Spires-Jones, director at the Centre for Discovery Brain Sciences at the University of Edinburgh, called it, "a very cool study highlighting how much our brains change over our lifetimes."
She said the findings "fit well" with what we know about brain ageing, but cautioned that "not everyone will experience these network changes at exactly the same ages."