This is as interesting as the aluminum can I tossed in the trash after I got off the train yesterday morning.
I think to truly dissociate like not normal dissociation, you need two things. You need early and persistent abuse without anyway out. You need a reason for dissociation. But I think you also need the neurology for dissociation. Now you might say all young minds are the same but I disagree. I think you need a specific type of mind that is quite detail oriented from the start. I have absolutely no evidence of the second claim.
Nevertheless all people can agree on that all abuse victims don't become dissociative. So there is another factor, whatever it is.
So, all abuse victims don't become dissociative, but most dissociative people are abuse victims. There was a thing I read (don't know where of course) that claimed other types of trauma also can cause dissociation, like war, but it is less likely than something personal.
Also, dissociation isn't an absolute, there are severe dissociative things like DID, but also lesser dissociation is part of c-PTSD.
I had a RL friend whom I thought I knew, yet that person got into a dissociative fugue and basically disappeared. The person coming back was not the person I used to know. Pretty freaky actually.