Well what makes the most sense psychologically is that each 'personality' has things they deal with better, and it's not that there's a specific trigger, per se. The theory behind DID is that the personality splits itself to deal with problems that the conscious personality can't take. Maybe one personality is nicer, more sociable and easily hurt, better able to perform everyday tasks, while another has a tougher skin and able to power through tough situations to protect themselves, but has trouble in social situations. So depending on the situation, when one personality starts to get upset or uncomfortable, that's the cue for the other one to 'take over'.
edited 22nd Dec '11 6:13:28 PM by NoirGrimoir
SPATULA, Supporters of Page Altering To Urgently Lead to Amelioration (supports not going through TRS for tweaks and minor improvements.)