Multiplicity, also known as plurality, is the psychological phenomenon in which a person displays multiple distinct personas. This phenomenon can feature in identity disturbance, dissociative identity disorder, and other specified dissociative disorders, among other things. Some individuals describe their experience of multiplicity as a form of neurodiversity, rather than something that demands a diagnosis. Since 1994, the Diagnostic and Statistical Manual of Mental Disorders no longer refers to "multiple personality disorder", favoring other terms. In a body that contains multiple personas, a "system" may associate behavior with each persona and switch among them. Somebody who experiences multiplicity is described as a "multiple," while a person who does not experience multiplicity can be described as a "singlet".
History
Throughout history, concepts of phantoms, muses, and fluid "selves" have been applied to this phenomenon. This has been extended to concepts such as tulpamancy. Additionally, some individuals throughout history have stated that they had been taken over by a spirit, soul, or ghost. Plato described the soul as tripartite, calling them Logos, Eros, and Thymus. According to Carter,Shakespeare showed examples of this via characters such as Hamlet and Macbeth who had distinct personalities. Carter claimed that Freud supported the notion of different personalities when he came up with the Id, Ego, and Superego, arguing that a split separates the conscious and unconscious mind. Carl Jung proposed: "The many contains the unity of the one without losing the possibilities of the many." Carter says that Italian psychologist Roberto Assagioli developed psychosynthesis, and hypothesized that an individual may not beconsciously aware of their many personae. American psychologist John G. Watkins used hypnosis to bring out different personalities.
Systems
Many people who experience multiplicity have a "system" of multiple, mostly-independent selves, each with a name, thoughts, emotions, behavioral patterns, preferences, and memories, along with a gender and sexual orientation. An individual's personae can adopt different ages, including as children, sometimes called littles. They can be grouped into subsystems or families. Favored terminology describes them as "members," "alters," or "resident persons". "Alter" has lost favor among the "plural" community because it implies that some personae are not fully realized. One member can control behavior for some period. This is often referred to as "fronting". "Switching" occurs when a different member begins to front. This can happen voluntarily or involuntarily. Systems are developed throughout childhood from age 6 to around 9 due to extensive trauma. Amnesia separates these memories, and this barrier prevents the child from fully integrating its experiences into one persona. Instead the separate identities develop independently. Specific alters may not know what other alters do while fronting. Within a system, a "main" host often lacks knowledge of past traumatic events. The main usually controls the body during quotidian activities. Each system is unique when it comes to organization, depth and breadth of memory, and how much control they can exercise over switching. Many multiples use "we" instead of "I." Multiples may perform well in day-to-day life. Some people use multiplicity as a means of coping. Online communities and forums support multiples and provide fora for discussing unique experiences. A 2017 study estimated that around 200 to 300 people were part of these communities; however, the online community is much larger.
