It genuinely baffles me that people still believe in endogenic "systems", read the fucking DSM 5 for more than two seconds and you'll see it blatantly says DID and other DISSOCIATIVE disorders are caused by CHILDHOOD TRAUMA.
So this post goes out to endo truthers. I'm gonna break down this disorder for you.
First, in childhood we are one person, however, our mind is split into ego states for the simplicity of learning and survival. When severe and repetitive trauma happens the child's brain seperates those ego states for the purpose of survival. This is the most commonly believed and accepted theory in the scientific community and had more backing than the core theory.
Second, when children reach the age of 6-9 their brains begin to fuse together those ego states to create a full personality, but when a traumatized child has had their ego states seperated with dissociative barriers they can't fuse, leading instead to the ego states developing as individual personalities on their own that hold specific roles and traits.
That child then grows up with any of the dissociative disorders, smaller traumas can just lead to unstable sense of self due to Depersonalization Derealization disorder, or more severe and repetitive trauma leads to disorders such as DID, OSDD, PDID, and UDD. In ramcoa cases they may be classified as a HC-DID system however that is not yet a "real" diagnosis in the DSM5 but it's being worked on because it's still a form of dissociative disorder caused by trauma.
So to dumb it down. Child has ALTER EGOS, child is TRAUMATIZED and DISSOCIATES, child develops with a DISSOCIATIVE DISORDER.
There is no fun disorder with "friends in your head" because DID and other dissociative disorders ARE NOT FUN!! Could I possibly believe in plurality in other forms if real reaserch and proof is brought to me? Yeah, maybe. Will I believe it until then? No. Either your mentally ill asf and want to roleplay, or you haven't done any real reaserch into an already chronically stigmatized disorder. Go fuck yourself.
And fyi if you are mentally ill and doing it for some reason to do with a different disorder that doesn't excuse your actions and you're still a shitty person.