History Main / SplitPersonality

* In ''WebAnimation/InanimateInsanity'', Paper is a friendly and innocent character, but after since his exile on Idiotic Island, he's gone insane and developed an evil personality, Evil Paper, who enjoys taking on acts of violence. He is triggered by the words [[TriggerPhrase"Idiotic Island."]] but later, Paper was able to defeat his evil side, and became sane again.

* In ''WebAnimation/HappyTreeFriends'', Flippy's evil personality, Fliqpy, is triggered by reminders of the W.A.R.
* In ''WebAnimation/InanimateInsanity'', Evil Paper is triggered by the words "Idiotic Island."

* In ''TabletopGame/DungeonsAndDragons'', the [[DemonLordsAndArchDevils Demon Lord]] Demogorgon has two heads, but it wasn't until the 3rd Edition that a source mentioned that each had a separate personality. The personality of his left head is named Aameul, the right is named Hethradiah. His two personalities rarely cooperate, and are often fierce rivals. Aameul favors deception, while Hethradiah favors destruction. Strangely, this war within himself often turns out in Demogorgon�s favor. For example, one legend tells how Hethradiah formed an alliance with a powerful lich queen, which left her vulnerable to assassins sent by Aameul. When they killed her, Demogorgon gained her power and lands, so both sides of him benefited.

* In ''WebAnimation/HappyTreeFriends'', Evil Flippy is triggered by reminders of the W.A.R.

* ''WesternAnimation/TheLegoMovie'': As a spoof of the GoodCopBadCop routine, the film has a police character who changes between a NiceGuy persona and a tough guy persona by rotating his head, [[SarcasmMode with the creative name]] of "Good Cop/Bad Coop".

Fictional split personalities can be similar to a real-life condition, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID). DID is a mental disorder in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with extreme long-term childhood trauma. The individual has no control over when the alters "switch", and may not remember what they did or what happened to them while another personality was active (dissociative amnesia). DID has often been mischaracterized in the media, and its status remains controversial to this day.

* ''Film/CrimeDoctorsManHunt'': Irene Cotter was completely dominated by her sister Natalie. When Natalie left home, Irene was completely lost and could only cope by pretending to be Natalie. Eventually it reached the point where she completely became Natalie whenever she assumed he identity, and it was as Natalie she committed the murders.

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with long-term childhood trauma. These alternate personalities are often referred to as "alters".

Though DID starts in childhood it often persists to adulthood. The individual has no control over when the alters "switch" and may not remember what they did or what happened to them while an alter was active (dissociative amnesia). Not all cases of multiplicity can be diagnosed as DID. People that don't meet DID criteria may instead be categorized as "Otherwise Specified Dissociative Disorder" (OSDD-1, formerly DD-NOS).

A variety of theories address the origin of DID and its relative conditions. DID has been found to always originate in childhood, often because of sexual abuse or similar experiences. The theory of structural dissociation proposes that everyone starts with an unintegrated personality; but when childhood is disrupted by incidents of extreme trauma the parts may not integrate resulting in DID. Other theories model DID as the result of coping with trauma by dissociating and imagining said trauma is happening to someone else. It's worth noting that rather than create a new identity from scratch the afflicted brain takes previously existing personality traits and compartmentalizes them as a form of dissociation. Thus DID therapy typically has the end goal of decompartmentalizing the brain so the personality traits and memories of the alters become integrated.

DID was originally called "Multiple Personality Disorder" but the name was changed to clarify that dissociation and separate identities were key[[note]]and was partially damage control by the American Psychological Association after a highly publicized series of scandals featuring unethical doctors faking cases of the disorder for attention and profit. At first the APA declared MPD as a whole was entirely fabricated by these doctors; as later research developed they gradually adjusted their positions.[[/note]]. The condition remains highly controversial in academia.

DID has long been represented (and misrepresented) in media. Though characters with split personalities are surprisingly common in fiction, most of them don't match the textbook definitions of DID. The most common case shown is where two (or more) alters switch with one another; some depictions show people experiencing life as one person (i.e. having the same mind, memory and desires) but with behavior modes or frames of mind that switch between distinct states. Many depictions of DID show inaccurate portrayals of the condition, such as instances where distinct alters [[AlternateIdentityAmnesia share memories]] and can access other alters' memories; instances where alters switch at will; or even instances where alters interact directly with ''each other'', such as cases where they're at war, have formed a truce or are allies.

[[ScienceMarchesOn In older media]] DID is often conflated with schizophrenia even by psychologist characters despite being unrelated. (Schizophrenia causes hallucinations, psychoses and thought disorders. The confusion comes from the word literally meaning "split mind" because a main symptom is scattered, unconnected thoughts.)

See also DoubleConsciousness, MindHive, SharingABody, IdentityAmnesia, JekyllAndHyde, NapoleonDelusion, SuperpoweredEvilSide, SplitPersonalityMerge, SplitPersonalityMakeover, SplitPersonalitySwitchTrigger, SplitPersonalityTakeover, ManySpiritsInsideOfOne, TwoBeingsOneBody and TalkingToThemself. If the split personality is an antagonist it's EnemyWithin. {{Shapeshifting}} is sometimes involved. If the personalities go back and forth FlipPersonality ensues.

Compare TraumaInducedAmnesia.

See also DoubleConsciousness, MindHive, SharingABody, IdentityAmnesia, JekyllAndHyde, NapoleonDelusion, SuperpoweredEvilSide, SplitPersonalityMerge, SplitPersonalityMakeover, SplitPersonalitySwitchTrigger, SplitPersonalityTakeover, ManySpiritsInsideOfOne, TwoBeingsOneBody and TalkingToThemself. If the split personality is an antagonist it's EnemyWithin. {{Shapeshifting}} is sometimes involved. If the personalities are going back and forth FlipPersonality
.
Compare
TraumaInducedAmnesia.

Though DID starts in childhood, it often persists into adulthood. The individual has no control over when the alters "switch", and may not remember what they did, or what happened to them, while an alter was active (dissociative amnesia). Not all cases of multiplicity can be diagnosed as DID. People that don't meet DID criteria may instead be categorized as "Otherwise Specified Dissociative Disorder" (OSDD-1, formerly DD-NOS).

A variety of theories address the origin of DID and its cousins. DID has been found to always originate in childhood, often because of sexual abuse. The theory of structural dissociation proposes that everyone starts with an unintegrated personality; but when childhood is disrupted by incidents of extreme trauma, these parts may not integrate, resulting in DID. Other theories model DID as the result of coping with trauma by dissociating and imagining that the trauma is happening to someone else. It's worth noting that rather than create a new identity from scratch, the brain afflicted with the disorder takes personality traits that are already there and heavily compartmentalizes them as a form of dissociation. Thus, therapy for DID typically has the end goal of decompartmentalizing the brain so that the personality traits and memories of the alters become integrated.

DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and was partially damage control by the American Psychological Association after a highly publicized series of scandals, featuring unethical doctors faking cases of the disorder for attention and profit. At first, the APA declared that MPD as a whole was entirely fabricated by these doctors; but as later research developed, they gradually adjusted their position.[[/note]]. The condition remains highly controversial in academia.

DID has long been represented (and misrepresented) in the media. Though characters with split personalities are surprisingly common in fiction, most of them don't match the textbook definition of DID. The most common case shown is where two (or more) alters switch with one another; some depictions show people experiencing life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states. Many depictions of DID show inaccurate portrayals of the condition, such as instances where distinct alters [[AlternateIdentityAmnesia share memories]] and can access other alters' memories; instances where alters can switch at will; or even instances where alters interact directly with ''each other'', such as cases where they're "at war", have formed a truce, or are allies.

[[ScienceMarchesOn In older media]], DID is often conflated with "schizophrenia" even by psychologist characters, despite the fact that DID and schizophrenia are completely unrelated disorders. (Schizophrenia causes hallucinations, psychosis, and thought disorders. The confusion comes from the fact that the word schizophrenia literally means "split mind", because a main symptom is scattered, unconnected thoughts.)

See also DoubleConsciousness, IdentityAmnesia, JekyllAndHyde, NapoleonDelusion, SuperpoweredEvilSide, SplitPersonalityMerge, SplitPersonalityMakeover, SplitPersonalitySwitchTrigger, SplitPersonalityTakeover, and TalkingToThemself. If the split personality is the antagonist, it's the EnemyWithin. {{Shapeshifting}} is sometimes involved. If the personalities are flipping back and forth, FlipPersonality often ensues.

Compare TraumaInducedAmnesia.

If the two personalities are aware of each other, expect a GollumMadeMeDoIt situation to develop. Resolving it may require the weaker of the two to say "ImNotAfraidOfYou!" If the SplitPersonality gets its own body, it becomes either a LiteralSplitPersonality or an EnemyWithout (if said personality is antagonistic or evil). See also HeroicSafeMode for one explanation as to how a side like this can be created.

* Brazilian movie ''Loucas pra Casar'' has Maria Lúcia, a woman with long-lasting marriage obsession, finding out her boyfriend has two lovers, exotic dancer Lúcia and overtly religious younger woman Maria. Then at the altar she finds out [[TheThreeFacesofEve all three]] were her - Maria Lúcia and her partner liked to act out sexual fantasies, but she became LostInCharacter.

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with long-term childhood trauma. These cases are often referred to as "systems".

Though DID starts in childhood, it often persists into adulthood. The individual has no control over when the alters "switch", and may not remember what they did, or what happened to them, while an alter was active (dissociative amnesia). Not all cases of multiplicity can be diagnosed as DID. Systems that don't meet DID criteria may instead be categorized as "Otherwise Specified Dissociative Disorder" (OSDD-1, formerly DD-NOS).

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with long-term childhood trauma, resulting in a system or a multiple rather than a singleton.

DID has long been represented (and misrepresented) in the media. Though characters with split personalities are surprisingly common in fiction, most of them don't match the textbook definition of DID. The most common case shown is where two (or more) alters switch with one another; some depictions show people experiencing life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states. Many depictions of DID show inaccurate portrayals of the condition, such as instances where distinct alters [[AlternateIdentityAmnesia share memories]] and can access other alters' memories; instances where alters can switch at will; or even instances where alters interact directly with ''each other'', such as cases where they're "at war", have formed a truce, or are allies. [[ScienceMarchesOn In older media]], DID is often conflated with "schizophrenia" even by psychologist characters, despite the fact that DID and schizophrenia are completely unrelated disorders. (Schizophrenia causes hallucinations, psychosis, and thought disorders. The confusion comes from the fact that the word schizophrenia literally means "split mind", because a main symptom is scattered, unconnected thoughts.)

DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and was partially damage control by the American Psychological Association after a highly publicized series of scandals, featuring unethical doctors faking cases of the disorder for attention and profit. At first, the APA declared that MPD as a whole was entirely fabricated by these doctors; but as later research developed, they gradually adjusted their position.[[/note]].

DID has long been represented in fictional settings. The most common case is where (or more) alters, each of whom may or may not [[AlternateIdentityAmnesia share memories]] and may or may not be able to access other alters' memories, may switch at will or involuntarily; they may be at war, or have formed a truce, or be allies. Some depictions show people experiencing life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states.

Though characters with split personalities are surprisingly common in fiction, most of them don't quite match the textbook definition of DID. [[ScienceMarchesOn In older media]], it will often be called "schizophrenia" even by psychologist characters, despite the fact that DID and schizophrenia are completely unrelated disorders. (Schizophrenia causes hallucinations, psychosis, and thought disorders. The confusion comes from the fact that the word schizophrenia literally means "split mind", because a main symptom is scattered, unconnected thoughts.)

DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and political damage control by the American Psychological Association after a highly publicized series of scandals featuring unethical doctors faking cases of the disorder for attention and profit. At first, the APA declared that MPD as a whole was entirely fabricated by these doctors; but as later research developed, they gradually adjusted their position.[[/note]]).

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with long-term childhood trauma, resulting in a system or a multiple rather than a singleton. Long thought to be rare and often misdiagnosed, DID actually occurs in about 1%-3% of the population.

Not all cases of multiplicity can be diagnosed as DID. Systems that don't meet DID criteria may instead be categorized as "Otherwise Specified Dissociative Disorder" (OSDD-1, formerly DD-NOS). Yet other systems are a healthy SplitPersonalityTeam or MindHive, working well together and functioning well in daily life. In the absence of impairment or distress, these systems need no diagnosis.

A variety of theories address the origin of DID and its cousins. The theory of structural dissociation proposes that everyone starts with an unintegrated personality; but when childhood is disrupted by trauma, these parts may not integrate, resulting in DID. Other theories model DID as the result of coping with trauma by dissociating and imagining that the trauma is happening to someone else. Non-traumatic causes for DID and healthy multiplicity have been the subject of very little research.

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and political ass-covering by the American Psychological Association, doing damage control after a highly publicized series of scandals featuring unethical doctors and Satanic Panic. At first, the APA declared that MPD was entirely fabricated by these doctors; but as the evidence for (distinctly non-satanic) MPD accumulated, they gradually adjusted their position.[[/note]] Nowadays, dismissing alters in a multiple system as "only a personality" comes off as offensive or ableist.)

Though DID starts in childhood, it often persists into adulthood. The individual has no control (at least initially) over when the alters "switch", and may not initially remember what they did, or what happened to them, while an alter was active (dissociative amnesia). To put all that in Tropese: you go to your HappyPlace while some poor RedShirt has to deal with the TraumaCongaLine or HumiliationConga—so stereotypically, the personality [[BeingTorturedMakesYouEvil who has to deal with it is not a nice person]]...

In fiction, two (or more) alters, each of whom may or may not [[AlternateIdentityAmnesia share memories]] and may or may not be able to access other alters' memories, may switch at will or involuntarily; they may be at war, or have formed a truce, or be allies. Some systems may experience life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states. This diversity of experiences is TruthInTelevision for what real multiples report experiencing.

It's worth noting that rather than create a new identity from scratch, the brain afflicted with the disorder takes personality traits that are already there and heavily compartmentalizes them as a form of dissociation. Thus, therapy for DID typically has the end goal of decompartmentalizing the brain so that the personality traits and memories of the alters become integrated.

Characters with a split personality are surprisingly common in fiction, but most of them don't quite match the textbook definition of DID. [[ScienceMarchesOn In older media]], it will often be called "schizophrenia" even by psychologist characters, despite the fact that DID and schizophrenia are completely unrelated disorders. (Schizophrenia causes hallucinations, psychosis, and thought disorders. The confusion comes from the fact that the word schizophrenia literally means "split mind", because a main symptom is scattered, unconnected thoughts.)

[[folder:Light Novels]]
* ''LightNovel/TheGardenOfSinners'':
** Averted: Tohko correctly identifies that what Shiki [[spoiler:used to have before her coma]] can't be dissociative identity disorder, given its complexity.
--->'''Shiki:''' There's nothing funny about having a dual personality.\\
'''Tohko:''' No, no. You know, you two don't have anything as pleasing to look at as dissociative identity disorder. Existing simultaneously, each having their own unique will, and on top of that your actions are coordinated. That sort of complex personality shouldn't be called a "dissociated identity," but rather a "united independent personality."
** Played straight with [[spoiler:Shiki's ''third'' personality in the epilogue, which she is unaware of and only surfaces when she's unconscious, making it closer to actual DID. The third personality is aware of her, but it's also omniscient, so you'd expect it to be.]]
* Happens twice in ''LightNovel/InvadersOfTheRokujyouma'':
** Kiriha develops a childlike personality she calls "Kii" after finding out that [[spoiler: the older boy she fell in love with as a child was her best friend via Time Travel]].
** Sanae after [[spoiler: she re-merges with her comatose body. In the latter case, the split is between the memories and personality Sanae developed as a ghost, and her more reserved original self.]]
* Shizuku from ''[[Anime/YukiYunaIsAHero Kusunoki Mebuki is a Hero]]'' has a split personality caused by child abuse from her parents. She's usually very quiet, but when in danger her outspoken berserker SHIZUKU personality comes out.
* Suzuho in ''LightNovel/MagiciansAcademy'' is usually quiet and meek, communicating only through [[TalkingWithSigns sketchbook messages]]. When she removes her ribbon, her other side comes out, which is the exact opposite in personality. Violent, talkative, and, for some reason, blue-haired.
* In ''LightNovel/{{Sukisho}}'', [[spoiler:both Sora and Sunao developed split personalities, Yoru and Ran respectively, due to experiences they were subjected to as children. The catch: the split personalities Yoru and Ran have a romantic relationship...unlike Sora and Sunao. Every now and then the split personalities will take over and some, or, depending on the degree of the situation, extreme awkwardness follows.]]
[[/folder]]

In real life, [[https://en.wikipedia.org/wiki/Dissociative_identity_disorder Dissociative Identity Disorder]] (or DID) is a condition in which more than one distinct personality can be observed at different times within a single individual's brain, often associated with long-term childhood trauma, resulting in a system or a multiple rather than a singleton. DID is an extremely rare disorder, with its very existence being a heavily debated topic among psychiatrists.

Not all cases of multiplicity can be diagnosed as DID. Systems that don't meet DID criteria may instead be categorized as "Otherwise Specified Dissociative Disorder" (OSDD-1, formerly DD-NOS).

A variety of theories address the origin of DID and its cousins. The theory of structural dissociation proposes that everyone starts with an unintegrated personality; but when childhood is disrupted by trauma, these parts may not integrate, resulting in DID. Other theories model DID as the result of coping with trauma by dissociating and imagining that the trauma is happening to someone else. On the more skeptical side, some experts state that DID cases are simply the result of doctors pushing patients to exaggerate or falsify symptoms for fame, as was the case in one of the most widely known and referenced early cases, ''Sybil''.

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder)

Though DID starts in childhood, it often persists into adulthood. The individual has no control over when the alters "switch", and may not initially remember what they did, or what happened to them, while an alter was active (dissociative amnesia). To put all that in Tropese: you go to your HappyPlace while some poor RedShirt has to deal with the TraumaCongaLine or HumiliationConga.

In fiction, two (or more) alters, each of whom may or may not [[AlternateIdentityAmnesia share memories]] and may or may not be able to access other alters' memories, may switch at will or involuntarily; they may be at war, or have formed a truce, or be allies. Some systems may experience life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states.

Characters with a split personality are surprisingly common in fiction, but most of them don't quite match the textbook definition of DID. [[ScienceMarchesOn In older media]], it will often be called "schizophrenia" even by psychologist characters, despite the fact that DID and schizophrenia are ''completely unrelated disorders''. (Schizophrenia causes hallucinations, psychosis, and thought disorders. The confusion comes from the fact that the word schizophrenia literally means "split mind", because a main symptom is scattered, unconnected thoughts.)

If the two personalities are aware of each other, expect a GollumMadeMeDoIt situation to develop. Resolving it may require the weaker of the two to say "ImNotAfraidOfYou!" If the Split Personality gets its own body, it becomes either a LiteralSplitPersonality or an EnemyWithout (if said personality is antagonistic or [[SuperpoweredEvilSide evil]]). See also HeroicSafeMode for one explanation as to how a side like this can be created.

Though DID starts in childhood, it often persists into adulthood. The individual has no control (at least initially) over when the alters "switch", and may not initially remember what they did, or what happened to them, while an alter was active (dissociative amnesia). To put all that in Tropese: you go to your HappyPlace while some poor RedShirt has to deal with the TraumaCongaLine or HumiliationConga--so stereotypically, the personality [[BeingTorturedMakesYouEvil who has to deal with it is not a nice person]]...

In fiction, two (or more) alters, each of whom may or may not [[AlternateIdentityAmnesia share memories]] and may or may not be able to access other alters' memories, may switch at will or involuntarily; they may be at war, or have formed a truce, or be allies. Some systems may experience life as one person (i.e. having the very same mind, memory, and desires), but with behavior modes or frames of mind that switch between several distinct states. This diversity of experiences is TruthInTelevision for what real multiples report experiencing.

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and political ass-covering by the American Psychological Association, doing damage control after a highly publicized series of scandals featuring unethical doctors and SatanicPanic. At first, the APA declared that MPD was entirely fabricated by these doctors; but as the evidence for (distinctly non-satanic) MPD accumulated, they gradually adjusted their position[[/note]]. Nowadays, dismissing alters in a multiple system as "only a personality" comes off as offensive or ableist.)

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder)[[note]]

(DID was originally called "Multiple Personality Disorder", but the name was changed to clarify that dissociation and separate identities were key to the disorder[[note]]and political ass-covering by the American Psychological Association, doing damage control after a highly publicized series of scandals featuring unethical doctors and SatanicPanic. At first, the APA declared that MPD was entirely fabricated by these doctors; but as the evidence for (distinctly non-satanic) MPD accumulated, they gradually adjusted their position[[/note]]. Nowadays, dismissing alters in a multiple system as "only a personality" comes off as offensive or ableist.)