My understanding is that it’s due to the incrediably plastic nature of a child’s brain.
An adult brain? Even just bruising it can cause serious and lasting harm. But a baby’s brain? You can take out HALF of it, literally cut half out, to no effect whatsoever. They grow into completely functional, bright/intelligent, normal healthy adults. With very little lag (about a year, less lag than even being bilingual causes... which is about 2 years). From the moment we’re born? Our brain cells start dying. We have zillions more brain cells, and potential pathways, as young children than we do as adult. (And by adult? Think puberty.) Which is what creates that incredible plasticity / ability to change & adapt. Another, less severe, example of that? One of the more fun studies out there asks children what can be made with a paper clip? The average high school senior can come up with about 8 things. The average kindergartner? Over 500. Why the disparity? A 5yo isn’t constrained by what “should” be. On any level. They blow up paper clips to being 10 miles wide, and orbiting the planet, to dock space ships at. They make paper clips edible, or the human body able to digest “paper clip metal”, and feed the world with them. And 498 other things.
Children’s brains? Are amaaaaaaaaazing :inlove:
Their physiology is at its absolute most vital, and their thoughts are completely unrestrained. Reality and imagination operate out of the same space. So both the physical brain itself, as well as the mind, are in this unique state that you’ll never find again in life. Even the most creatively brilliant adults, who hang onto child-like thought processes? (And that shows, when you stick them in an imaging machine, not just on paper). When researchers stick those genius level artists, scientists, business, leaders, Nobel prize type peeps, etc. next to a boringly average even mediocre 4yo? The 4yo outperforms them. Not at a skill level, or a language level, but at a neurological level. Because those brilliant child-like adults? Light up brain scans like XMas. Easily 10x brighter/more colorful than the average adult, when asked to think about -or do- the exact same thing. But the 4yo? Their brain lights up like the sun.
Something else wicked cool about children’s brains? Each and every single personality disorder out there, is a part of normal childhood development. Which is why they cannot be diagnosed in childhood. (They have to be “enduring and persistent”. Existing not only throughout childhood but also significantly into adulthood.) In point of fact, not passing through those stages is highly indicative of a problem (either a neurodevelopmental disorder being present blocking normal development or atypifying it, or one of those personality disorders locking in/attempting to lock in). Children’s brains just DO that... reach for extremes impossible for adult brains to reach at all, and then recede back like a wave on a beach, to find a balanced normal. And then they do it again. And again. And again. To create a personality disorder? Something has to essentially “stop the tide”. Literally preventing the brain from recalling itself from the extreme it reached, AND preventing further development in other areas. It takes a perfect storm of events to achieve that, and it’s simply not possible -many many many people have tried- to accomplish in adults. Adults go mad. In a few different, yet highly predictable ways. (I’m not joking about people attempting to break other people, in too many different ways to count. Very predictible results follow.) It takes a child’s brain to be able to ADAPT in such a way, to not only function in that extreme, but to thrive, and completely build a person/personality in those conditions.
So my understanding is that’s why children’s brains can create wholly different personalities under certain circumstance. Becoming exactly who they need to be, in that situation. 1 beating heart, 2 souls. Or more. Adults can -and often do- shatter into fragments of themselves (one of those very predicitble results)... but some kids, when the pressure is too much for any 1 person to bear? Instead of shattering like adults? Think to themselves, well... then I need 2 people. Let’s do that. And they do. Because kids? Are f*cking amazing.