Brain Eras
A recently published study suggests that rather than existing in a continuous state, or passing through just a few phases, the human brain actually seems to have five distinct eras.
These phases, identified using brain imaging datasets paired with 12 metrics of organizational change, show that most of us have one brain setup from birth to nine-years-old, another from nine to 32, another from 32 to 66, another from 66 to 83, and then a final brain era from 83, onwards.
These phases, called Childhood, Adolescence, Adulthood, Early Aging, and Late Aging, respectively, challenge existing beliefs about how our brains develop and change over the course of our lives, including the surprising revelation that our adolescent period, which begins at the onset of puberty, doesn’t end until our early-30s (prior research had suggested that for most people, this phase ended in our mid-20s).
That Adolescent period is the only phase during which our brains become more efficient, as our Childhood brain is all about soaking up knowledge and know-how near-randomly, our Adulthood phase, the longest of all brain phases, brings stability to our neurological setups, our intelligence and personalities plateauing to some degree, and when we hit our Early Aging phase at around age 66, we begin to see a slow decline predicated on the separation of our brain into independently cohesive, but less interconnected and collaborative regions. The final stage, Late Aging, sees that brain-fracturing speed up, which leads to more rapid neurological decline.
It’s important to note that every brain is different, and we’ll all experience these sorts of phases at different times—this is just a rough, averaged estimate based on existing datasets. We also don’t have a good sense of how these phases correlate with things like sex, lifestyle, environment, and genetic differences between people.
Like most such categorization efforts, though, this does provide a loose heuristic that can be useful for understanding where we and others are in life, in terms of how our brains function and what they’re optimized for, and it could aid in the development of treatments and habits that might help folks cope with the downsides of each new neurological era.