basics
The word "system" is an umbrella term used to describe people who are affected by dissociative identity disorder or otherwise specified dissociative disorder, type 1. These disorders are characterized by two or more states of self (called alters) present within one body.⁽¹⁾ This is a result of severe and prolonged childhood trauma, in which a child dissociates to separate themself from the trauma that they're facing as a method of coping. The disorders cause a disruption in one's identity that is not part of a normal, broadly accepted cultural or religious practice.⁽²⁾
Systems are developed in response to repeated and/or prolonged childhood trauma.⁽¹⁾ This trauma often comes in the form of abuse, but can also be the result of a frightening or unpredictable home environment, natural disasters, war, and many others.⁽³⁾⁽⁴⁾