History SplitPersonality / Literature

* In one ''Literature/{{Animorphs}}'' novel, ''The Separation'', Rachel's personality goes so far as to be split into two physically different people -- one timid, gentle, and pacifistic; the other ruthless, violent, and obsessive -- when she gets cut in half while in starfish morph. Because of starfish's regenerative powers, she "grows back" a ''whole extra person.''

* Margaret Millar's Edgar-award winning thriller ''Beast In View'', in which a woman who is apparently the victim of a malevolent stalker turns out to be being persecuted by her own malevolent alternate personality, is the UrExample in the crime genre of the "the villain is actually the hero's or [=PoV=] character's evil alternate" idea. Unfortunately, it later became a groanworthy cliche due to simplistic and/or logistically impossible examples.

* Subverted in ''Literature/{{Blindsight}}'': one of the characters is a linguist with ''three'' surgically-induced alter personalities (known collectively as the Gang of Four). Some time is taken up in discussion of twentieth-century attitudes towards MPD, which are largely dismissed as barbaric and irrational. The Gang are a relatively realistic depiction of co-conscious multiple systems[[note]]and yes, these exist in reality[[/note]], where all of the personalities [[SplitPersonalityTeam know of the others' existence and cooperate]].
** In the sequel, ''Literature/{{Echopraxia}}'' it turns out that [[spoiler: vampires are outright {{Mind Hive}}s, and Valerie bypassed the crucifix glitch by sacrificing one of her parallel processes. Similar to the 20th cen hypothesis of D.I.D. that the Gang dismissed as "irrational". Though they did exist before the trauma and vampires are complete sociopaths.]]
* In Creator/JackVance's ''[[Literature/TheDemonPrinces The Book of Dreams]]'', Howard Alan Treesong, the last Demon Prince, has five separate personalities.
* Severian in The ''Literature/BookOfTheNewSun'', who is both the original torturer Severian and also Chatelaine Thecla after eating the Albazo (and Thecla.)

* Happens to some of the Clayborn in David Wingrove's ''Literature/ChungKuo'' series when under severe pressure.
* In Creator/StephenKing's ''Franchise/TheDarkTower'' series introduces two characters in [[Literature/TheDrawingOfTheThree the second book]]: Odetta Holmes, a fairly well-to-do black woman who lost her legs and is generally surviving the 1960's as best she can; and Detta Walker, who is dangerous, brutal, and very bitter. The two personalities are almost completely unaware of each other, at least until the plot comes knocking. [[spoiler:At the book's climax, the two personalities integrate into Susannah Dean, who possesses the good sense of the former, and the tenacity and will of the latter]]. Odetta/Dedda is often referred to as "schizophrenic," which is {{Justified|trope}} in this case as most of the characters' information on the disorder comes at second- or third-hand from Eddie's recollections of [=80s=] pop culture.

* Altogether Andrews, from Creator/TerryPratchett's ''Literature/{{Discworld}}'' series, has ''eight'' personalities, none of which answer to Andrews. There's also Agnes Nitt and her alter ego [[AwesomeMcCoolName Perdita X. Dream]], which started out as a name she thought was cool in ''Literature/LordsAndLadies'', then became the embodiment of her id in ''Literature/{{Maskerade}}'', then became a full-on Split Personality in ''Literature/CarpeJugulum''.
** This is apparently not that uncommon on the Discworld. Perdita is explained as having come about specifically because Agnes took a part of herself -- her desire to not be a nice girl with a good personality -- and gave it a name. Her senior witches muse to themselves that giving something a name gives it life, too. Rincewind's conscience and Sam Vimes's inner rage are also sometimes depicted as semi-sentient, especially in ''Night Watch'', where Vimes refers to it as "The Beast". In ''Thud!'', we find Vimes also has an "inner watchman", who [[spoiler:ends up [[HeroicWillpower kicking a powerful vengeance spirit out of Vimes' mind.]]]]
** Mightily Oates also suffers from this, dividing into a skeptic part and a devout part. At one point, he considered having himself exorcized. And, like Agnes/Perdita, he is resistant to vampiric mind control, because they can control only one mind per brain.
** ''Literature/{{Thud}}!'' also features Pointer and Pickles, the owners of a rock collector's shop, who turn out to be the split personalities of the same woman.

* Janis Cordelia Plumtree in ''Literature/EarthquakeWeather'' by Creator/TimPowers, whose condition is complicated by the fact that [[spoiler:one of her personalities is actually the spirit of her dead father]].
* In the two part ''Literature/FearStreet'' story ''Fear Hall'', it turns out that [[spoiler:Hope Mathis' three friends, Jasmine, Angel, and Eden, as well as her homicidal boyfriend Darryl are actually split personalities, created due to her mother's abusive treatment towards her.]]

* Used as a MindScrew in ''Literature/{{Ghoul}}'' by Creator/MichaelSlade. The BigBad of the novel, [[spoiler: Saxon Hyde]] comes from an "old money" family where madness runs in the genes. The villain's DID is the result of childhood sexual abuse, ''however'' upon another traumatic event, the villain suffers a complete break with reality and it becomes [[ItMakesSenseInContext full-blown paranoid schizophrenia.]] A veritable grab-bag of crazies, all in one character.

* Ellen Hopkins' ''Identical'' has a more realistic case of this. Near the end, it is revealed that [[spoiler:Kaeleigh has DID and Raeanne is her other personality. The real Raeanne died in a car accident during the twins' childhood.]]

* {{Averted}} in Geoph Essex's ''Jackrabbit Messiah'': Jack has [[ShownTheirWork schizophrenia]], not [[HollywoodPsych DID]], though the end result is that he plays [[OddCouple Oscar Madison to the Felix Unger]] living inside his head, suggesting similarities to the favorite sort of fictional split personality (especially during a [[LiteralSplitPersonality more surrealistic portion of the climax]]).

* The titular Dragonlords from ''The Last Dragonlord'' are born with two souls/identities: one human and one dragon. This overlaps into SharingABody in that the two personalities are fully aware of each other and converse at times. The main character, Linden, has trouble controlling [[GollumMadeMeDoIt the anger issues]] of his dragon side, Rathan. His mate's infant-like dragon side refuses to acknowledge her.

* In ''Literature/TheLordOfTheRings'' and related materials, it is suggested that [[GollumMadeMeDoIt Gollum's personality]] developed from Sméagol talking to the Ring ("my precious") which he eventually identified as part of himself, as well as his desire to place the blame for the murder of his friend Déagol onto someone else.
** Gollum's split personality never appeared in the first edition of ''Literature/TheHobbit'': it only shows up first in the {{rewrite}}, when Bilbo hears them discussing after realizing that Bilbo had the Ring all along. At the time of writing the first edition, the Ring wasn't evil yet in Tolkien's mind, and so had no reason to poison Sméagol's mind.
* ''Literature/TheMindsOfBillyMilligan'' is the true story of a man with multiple personalities. Billy Milligan & co. came to public attention ''before'' Sybil.
* [[http://astraeasweb.net/plural/multiples-silverberg.html Multiples]] by Creator/RobertSilverberg. TwentyMinutesIntoTheFuture multiple personality is accepted and respected as a variant normal lifestyle, similar to being gay. Many groups form [[SplitPersonalityTeam cooperating teams]], keeping logs if they can't communicate directly. The main character, a singlet, first poses as a multiple, then tries experimental treatment to see if she can become multiple for real.

* This is the major twist of Sara Shepard's two-book ''Perfectionists'' series[[note]]consisting of ''The Perfectionists'' and ''The Good Girls''[[/note]]. Five girls--Caitlin, Mackenzie, Ava, Julie, and Parker--were put together in a small group discussion in one of their classes, and discovered that they all hate the same guy for understandable reasons. They discussed a hypothetical scenario of how they would kill him and other people in their lives that they hate, only for this guy and some others on their list to die in exactly the manner they discussed, leading them to try to find the real killer to [[ClearMyName clear their names]]. The killer, however, turns out to be [[spoiler:Parker]], who is revealed to have been a split personality of [[spoiler:Julie]] all along. [[spoiler:The real Parker was beaten to death [[AbusiveDad by her dad]] more [[DeadAllAlong than a year ago]], and Julie, her best friend, who could have potentially prevented it from happening, was so grief-stricken and guilt-ridden by this (which was greatly exacerbated by Julie's own abusive and broken home life) that her personality fragmented and created the "Parker" alter as a way to keep her friend alive. "Parker" served as an outlet for the darker parts of Julie's personality, and hurt and killed the people she did in a misguided effort to protect and stand up for Julie's and "her" friends.]]
* In Amelia Atwater-Rhodes' ''Persistence of Memory'', Erin suffers from DID with the complication that [[spoiler:her alter comes from psychic residue from a vampire attack on her pregnant mother. While the alter that manifests is just the psychic remnant, the basis for Erin's alter, Shevaun, is a very real and very dangerous vampire.]]
* The entire premise of Liz Coley's "pretty girl-13", in which the protagonist returns home after being missing for three years with no memory of what happened. [[spoiler: Turns out, she's got DID, which actually began because her uncle sexually abused her.]]
* Done in a fairly realistic way in Matt Ruff's ''Literature/SetThisHouseInOrder'' with two characters who both have DID. Both suffered severe abuse as children, but one has been aware of this problem for a long time, and all the personalities work together and see a psychiatrist. The other character is younger and less aware of what is going on, and is afraid because she keeps having periods of memory loss. Both characters eventually work towards the goals of overcoming abuse, getting treatment, and choosing between full integration and trying to function by having all personalities cooperate with each other.

* OlderThanRadio: In the classic Robert Louis Stevenson novel ''Literature/TheStrangeCaseOfDrJekyllAndMrHyde'', Dr. Henry Jekyll develops a formula that separates his good and evil personalities. By drinking the potion, he can transform himself into the villainous Edward Hyde.

* Ted Dekker's thriller novel ''Literature/Thr3e'' (as well as TheFilmOfTheBook): [[spoiler:The killer who's been chasing the protagonist is actually a split personality of the protagonist. But wait! Isn't the title "three"? That's right! It turns out his childhood friend who's been helping him solve the mystery is ''also'' one of his split personalities.]]
* The protagonist of Simon Hawke's ''Tribe of One'' trilogy (set in the ''TabletopGame/DarkSun'' setting of ''TabletopGame/DungeonsAndDragons'') is a man with more personalities than he can count, who [[WalkingTheEarth walks Athas]] in search of a way to bring his fractured mind together.
* In Creator/MichaelFlynn's ''[[Literature/SpiralArm Up Jim River]]'', Donovan. His multiple personalities were induced deliberately, but the manner was bungled -- also, perhaps, deliberately.

* Creator/LoisMcMasterBujold's ''Literature/VorkosiganSaga'':

* In Creator/JamesSwallow's ''TabletopGame/{{Warhammer 40000}}'': ''[[Literature/BloodAngels Red Fury]]'', the BloodMagic gives the Bloodfiends the GeneticMemory of all those whose blood they drank, giving them effective multiple unintegrated personalities -- and a fierce desire to drink more blood, worsening the problem. Rafen, fighting one, can clearly [[WasOnceAMan recognize the source of its blood]], and {{dying|AsYourself}}, it might have said, "Brother."

* In ''When the Bough Breaks'' (part of Creator/MercedesLackey's ''[=SERRAted Edge=]'' series), a young girl develops multiple personalities when her father starts raping her. One personality takes over whenever she realizes a rape is about to occur, to protect the other personalities from knowing what's been going on.
* Mark Meadows, AKA "Captain Trips," of the ''Literature/WildCards'' series. Normally a smiling, weirdly dressed, and rather ineffectual hippy (albeit one with great skills in biochemistry), in time of need, his various powders and potions are capable of making him an ace of badass proportions... or rather, several aces, depending on which one he takes. All of them have a different mind and personality, and most of them think the good Captain is a wimp or worse, and do everything they can to keep from reverting when the chemical wears off.
* ''Literature/XWingSeries'': Wraith Squadron's "Runt" manages to skirt the reality issue by being, well, an alien - he has a number of highly specialized minds, such as the Pilot and the Student; this is noted to be natural and healthy for his species, and learning to switch quickly between personalities is helpful for him. Lara Notsil/Gara Petothel/Kirney Slane, though she might appear to fit the trope and once dreamed of her [[DoubleConsciousness different personae arguing]], is really a spy who started BecomingTheMask and soon had a [[HeelFaceTurn genuine desire to defect]], as well as some unstable identity issues. No split personality.
* ''Literature/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 ''Literature/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 ''Literature/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 ''Literature/{{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.]]

* In Creator/StephenKing's ''Franchise/TheDarkTower'' series introduces two characters in [[Literature/TheDrawingOfTheThree the second book]]: Odetta Holmes, a fairly well-to-do black woman who lost her legs and is generally surviving the 1960's as best she can; and Detta Walker, who is dangerous, brutal, and very bitter. The two personalities are almost completely unaware of each other, at least until the plot comes knocking. [[spoiler:At the book's climax, the two personalities integrate into Susannah Dean, who possesses the good sense of the former, and the tenacity and will of the latter]]. Odetta/Dedda is often referred to as "schizophrenic," which is {{justified}} in this case as most of the characters' information on the disorder comes at second- or third-hand from Eddie's recollections of [=80s=] pop culture.

* The [=AIs=] in ''Literature/AncillaryJustice'' have a mild version of this. While [[HiveMind ancillaries share a single identity]], each body retains its individual emotions so they don't get trapped in endless loops of logic or give undue attention to pointless details. An individual ancillary's feelings toward a person can color the whole AI's perception of that person and affect its behavior, since the ancillaries all share one mind. If they decide they don't like you, they can make your life inexplicably uncomfortable, and Amaat help you if you [[MamaBear hurt someone they like]]. [[spoiler:[[TheEmperor Anaander Mianaai]] is a straighter example as well.]]

* ''LightNovel/TheGardenOfSinners'':

* Happens twice in ''LightNovel/InvadersOfTheRokujyouma'':

* 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.]]

* ''Literature/XWingSeries'': Wraith Squadron's "Runt" manages to skirt the reality issue by being, well, an alien - he has a number of highly specialized minds, such as the Pilot and the Student; this is noted to be natural and healthy for his species, and learning to switch quickly between personalities is helpful for him. Lara Notsil/Gara Petothel/Kirney Slane, though she might appear to fit the trope and once dreamed of her [[DoubleConsciousness different personae arguing]], is really a spy who started BecomingTheMask and soon had a [[HeelFaceTurn genuine desire to defect]], as well as some unstable identity issues. No split personality.

* ''Literature/{{Oathbringer}}'' (third book of ''Literature/TheStormlightArchive''): Shallan Davar falls into an downward spiral in this book, and creates multiple new personalities with her [[MasterOfIllusion Lightweaving]] to deal with situations she isn't confident enough to handle. It started in ''Literature/WordsOfRadiance'' with the thief persona, Veil, then develops when she creates the warrior Brightness Radiant to handle using her Shardblade, and eventually leads to the personalities leaking out unintentionally and her considering "Shallan" as just another alternate personality. [[spoiler:Eventually, she is forced to come to terms the limits of her personalities when her actions unintentionally lead to the death of a young boy and that Veil doesn't actually have the experience as she pretends to. This ends up with her uncertain and very confused with her self as her personalities constantly switch out with one another. In the final battle we see from all three perspectives as she is constantly switching between them, including speaking as all three different personas in a conversation... and it's revealed that Shallan is just an illusion at the moment, and Radiant is the real one.]]

* This is the major twist of Sara Shepard's two-book ''Perfectionists'' series[[note]]consisting of ''The Perfectionists'' and ''The Good Girls''[[/note]]. Five girls--Caitlin, Mackenzie, Ava, Julie, and Parker--were put together in a small group discussion in one of their classes, and discovered that they all hate the same guy for understandable reasons. They discussed a hypothetical scenario of how they would kill him and other people in their lives that they hate, only for this guy and some others on their list to die in exactly the manner they discussed, leading them to try to find the real killer to [[ClearMyName clear their names]]. The killer, however, turns out to be [[spoiler:Parker]], who is revealed to have been a split personality of [[spoiler:Julie]] all along. [[spoiler:The real Parker was [[DomesticAbuse beaten to death]] [[ParentalAbuse by her dad]] [[DeadAllAlong more than a year ago]], and Julie, her best friend, who could have potentially prevented it from happening, was so grief-stricken and guilt-ridden by this (which was greatly exacerbated by Julie's own abusive and broken home life) that her personality fragmented and created the "Parker" alter as a way to keep her friend alive. "Parker" served as an outlet for the darker parts of Julie's personality, and hurt and killed the people she did in a misguided effort to protect and stand up for Julie's and "her" friends.]]

* This is the major twist of Sara Shepard's two-book ''Perfectionists'' series[[note]]consisting of ''The Perfectionists'' and ''The Good Girls''[[/note]]. Five girls--Caitlin, Mackenzie, Ava, Julie, and Parker--were put together in a small group discussion in one of their classes, and discovered that they all hate the same guy for ''very'' understandable reasons. They discussed a hypothetical scenario of how they would kill him and other people in their lives that they hate, only for this guy and some others on their list to die in exactly the manner they discussed, leading them to try to find the real killer to [[ClearMyName clear their names]]. The killer, however, turns out to be [[spoiler:Parker]], who is revealed to have been a split personality of [[spoiler:Julie]] all along. [[spoiler:The real Parker was [[DomesticAbuse beaten to death]] [[ParentalAbuse by her dad]] [[DeadAllAlong more than a year ago]], and Julie, her best friend, who could have potentially prevented it from happening, was so grief-stricken and guild-ridden by this (which was greatly exacerbated by Julie's own abusive and broken home life) that her personality fragmented and created the "Parker" alter as a way to keep her friend alive. "Parker" served as an outlet for the darker parts of Julie's personality, and hurt and killed the people she did in a misguided effort to protect and stand up for Julie's and "her" friends.]]

* This is the major twist of Sara Shepard's two-book ''Perfectionists'' series[[note]]consisting of ''The Perfectionists'' and ''The Good Girls''[[/note]]. Five girls--Caitlin, Mackenzie, Ava, Julie, and Parker--were put together in a small group discussion in one of their classes, and discovered that they all hate the same guy. They discussed a hypothetical scenario of how they would kill him and other people in their lives that they hate, only for this guy and some others on their list to die in exactly the manner they discussed, leading them to try to find the real killer to [[ClearMyName clear their names]]. The killer, however, turns out to be [[spoiler:Parker]], who is revealed to have been a split personality of [[spoiler:Julie]] all along. [[spoiler:The real Parker was [[DomesticAbuse beaten to death]] [[ParentalAbuse by her dad]] [[DeadAllAlong over a year ago]], and Julie, her best friend, who could have potentially prevented it from happening, was so grief-stricken and guild-ridden by this (which was greatly exacerbated by Julie's own abusive and broken home life) that her personality fragmented and created the "Parker" alter as a way to keep her friend alive. "Parker" served as an outlet for the darker parts of Julie's personality, and hurt and killed the people she did in a misguided effort to protect and stand up for Julie's and "her" friends.]]

* This is the major twist of Sara Shepard's two-book ''Perfectionists'' series[[note]]consisting of ''The Perfectionists'' and ''The Good Girls''[[/note]]. Five girls--Caitlin, Mackenzie, Ava, Julie, and Parker--were put together in a small group discussion in one of their classes, and discovered that they all hate the same guy. They discussed a hypothetical scenario of how they would kill him and other people in their lives that they hate, only for this guy and some others on their list to die in exactly the manner they discussed, leading them to try to find the real killer to [[ClearMyName clear their names]]. The killer, however, turns out to be [[spoiler:Parker]], who is revealed to have been a split personality of [[spoiler:Julie]] all along. [[spoiler:The real Parker was [[DomesticAbuse beaten to death]] [[ParentalAbuse by her dad]] [[DeadAllAlong over a year ago]], and Julie, her best friend, who could have potentially prevented it from happening, was so grief-stricken and guild-ridden by this (which was not helped by Julie's own abusive and broken home life) that her personality fragmented and created the "Parker" alter as a way to keep her friend alive. "Parker" served as an outlet for the darker parts of Julie's personality, and hurt and killed the people she did in a misguided effort to protect and stand up for Julie's and "her" friends.]]