Scientists Identify Five Distinct Eras of Human Brain Aging
November 25, 2025
2 min reading
Scientists identify five distinct eras of human brain development
The human brain goes through five distinct phases of life, each defined by its own set of characteristics, new study finds
A representative magnetic resonance imaging (MRI) tractography image of the early human brain era. In a new study, this image is representative of the general pattern seen in the brain during the second era of neuronal wiring, the adolescent phase.
Alexa Mousley/University of Cambridge
The human brain experiences five distinct eras as we age, and each is defined by changes in our neural architecture that influence how we process information, new research shows. The brain changes associated with these stages shape how our minds age and eventually decline.
In a study published Tuesday in Natural communications, The researchers compared the brain scans of 3,802 people aged zero to 90. By mapping the brain’s connections over time, scientists detected four turning points in brain structure over the course of a human life: at nine years, 32 years, 66 and 83 years.
This means, according to researchers, that the connections in our brain work in roughly the same way from birth to age nine. Then, our neural architecture begins to organize itself differently as we enter adolescence, up until age 32. At this point, the brain’s structural development appears to reach its peak, the study found.
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“What we found suggests that the journey from childhood brain development to this peak in the early 30s is distinct from other phases of life,” says Alexa Mousley, lead author of the study and a neuroscientist at the University of Cambridge.
“This does not mean that the brain of a 17-year-old and a 30-year-old are identical, but specifically that the types of changes that occur … are consistent,” she adds.
At age 32, the longest era of brain rewiring begins, marking the beginning of the adult years. It’s at this stage that brain architecture begins to stabilize compared to previous phases, and Mousley says this fits with previous research that found there is also a “plateau in intelligence and personality around this time.”
After the mid-60s, brain connections begin to deteriorate. And at the final turning point, 83 years ago, connectivity declined even further.
In a recent statement, Duncan Astle, professor of neuroinformatics at Cambridge and co-author of the study, said these epochs of brain development could reflect how humans experience changes over time.
“Looking back, many of us feel that our lives were characterized by different phases,” he said. “It turns out that brains go through these eras, too.”
It’s not clear what these major changes can tell us about learning and brain development, Mousley says. Previous research has also highlighted distinct phases of brain development across the lifespan, and it remains unclear how lifestyle factors or other variables may influence brain aging in individuals. And while the new study finds a clear peak in effectiveness in your early 30s, this could be linked to evolution, lifestyle changes, or genetic factors.
“These are just potential ideas – we really don’t know,” she says.
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