Remember a few (or five) years back when new research came out that upended the longstanding practice of calculating dogs’ ages at seven years for every one human year? Well, now they’ve done it for humans. Sort of. Last week neuroscientists at the University of Cambridge unveiled a study which maps out five stages across four major turning points of brain development that our species go through, and the corresponding ages for these stages is a bit different than what you might expect. We begin life with the “childhood brain” that lasts from birth to age nine. Next is the “adolescent brain” that extends through — wait for it — 32! Meaning our brains only start adulthood at 32?? Actually… this explains a lot. “Adult brain” stays with us for the longest of any brain stage, until 66 when we enter “early aging brain” and finally cross into the last stage of “late aging brain” at 83. I feel I’ve aged just reading the results of this study.
“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,” lead researcher Dr. Alexa Mousley, told the BBC, adding that this can happen at different ages for different people.
Mousley’s study published in Nature Communications, reveals that the first phase of the brain — called the “childhood brain” — lasts until the age of 9. During this time, human brains are defined by “network consolidation,” where synapses are whittled down and rewired.
After the age of 9, the brain enters the adolescence phase, which lasts until the early 30’s. During this time, “white matter” continues to grow in volume in the brain, and “organization of the brain’s communications networks is increasingly refined,” according to the study.
This is also the time when the brain undergoes one of its biggest changes within a person’s lifespan.
“Around the age of 32, we see the most directional changes in wiring and the largest overall shift in trajectory, compared to all the other turning points,” Mousley added, per the release.
“While puberty offers a clear start, the end of adolescence is much harder to pin down scientifically,” she added. “Based purely on neural architecture, we found that adolescent-like changes in brain structure end around the early thirties.”
After the age of 32, a person’s brain enters its adulthood era, which is the “longest era” of the brain. During this phase, the brain’s architecture stabilizes, leading to a period without “major turning points” in cognitive abilities or personality traits.
This lasts until the age of 66, when the human brain enters the early aging period. During this time, there is a “gradual reorganization of brain networks” with “reduced connectivity as white matter starts to degenerate,” according to Mousley.
“This is an age when people face increased risk for a variety of health conditions that can affect the brain, such as hypertension,” she added.
The final turning point of the brain happens at the age of 83, when a person enters the late aging brain phase. While the research noted that “data is limited for this era,” they said that in this final period, “brain connectivity declines even further, with increased reliance on certain regions.”
“After the age of 32, a person’s brain enters its adulthood era … a period without ‘major turning points’ in cognitive abilities or personality traits.” Oh no. No no no no no. I must insist on being an outlier to these findings. I do NOT want my 30s brain to be the one I spend the most time with in this life!! This has not been the best version of Kismet, she could definitely do with some cognitive (and personality) improvements. I guess this is also hitting a nerve (neuro pun!) because I am staring a birthday square in the eye this week where I will be marching further upwards of 32 and I’m not all that happy about it and see! don’t my ramblings sound like the whiny lamentations of a teenager still stuck in adolescence?! To be clear, I’m not knocking this study (pro-science here!), I’m just having a mini aging meltdown. Actually, the idea of not starting adulthood until 32 resonates a lot; it reminds me of something my father said to me several years ago, that I was living my life out of order. I was a very precocious, very winning kid. My adulthood — or what we thought was adulthood — has felt much more muddled. Turns out my brain has been on track all along, and that’s kind of comforting. I just need some leeway so it’s not a hard 32 for the switchover.
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