History Main / TheMindIsAPlaythingOfTheBody

Compare BecomingTheMask, ShapeshifterModeLock and AndIMustScream; contrast DifferentForGirls. May lead to/from SenseLossSadness. Often overlaps with FurryReminder and/or MyInstinctsAreShowing.

* Certain aspects of one's personality can be affected majorly by the health of the bacteria in one's digestive system. Patients who have had to undergo serious procedures that result in their entire digestive tract being sterilized have been noted to have personality alterations. The easiest way to fix this is by transplanting someone else's gut fauna (usually in the form of [[{{squick}} capsulized feces]], thankfully as a suppository and not oral pill) into the person - in some circumstances, the patient was then observed as behaving and acting like the donor.
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---> '''Hero''': Wow! I can't explain, but I'm happy! I'm a human being, but I like this place. I feel weirdly happy! It might be an instinct thing for Pokémon... Maybe this is what it feels like to want to wag your tail... It doesn't matter! I'm happy! [[LampshadeHanging Maybe I feel that way because I'm <Pokémon>]]!

* Sleep deprivation. Its something that everyone has experienced, and for an unfortunate many quite frequently, and even if you are not very aware on how you change when sleep deprived, you have probably seen how someone else who is sleep deprived who is usually calm or cheerful become cranky.

[[folder:Web Originals]]

** It's actually specifically mentioned in a few of the original stories (such as Fey 1) that being an Exemplar (Mutant with MostCommonSuperpower as an actual power) specifically invokes this trope. That is to say that as a rule, if you are shape-changing due to being an Exemplar, eventually you'll get used to your new body -- no matter if it's female, a mutant T-Rex, or a giant piece of sentient coral. The fact that [=BITs=] are generally based on the Exemplar's subconscious idea of a perfect body also helps.

* A minor version in ''WesternAnimation/UltimateSpiderMan2012'', for laughs: after Mesmero causes Spiderman and Wolverine to switch bodies, Spiderman (in Wolverine) uses the [[CatchPhrase "I'm the best there is at what I do"]] line (followed by "...and I have no idea why I said that"), whereas Wolverine (in Spiderman) realises that he talks as much about inane things as Spidey does, even when there's no one to hear him.

* ''Roleplay/EquestrianLegends'' has Meadow: formerly a pony, now a dragon, and with powerful instincts.

** [[Recap/DoctorWhoS29E4DaleksInManhattan "Daleks in Manhattan"]]/[[Recap/DoctorWhoS29E5EvolutionOfTheDaleks "Evolution of the Daleks"]]: Dalek Sec merges himself into a Dalek/Human hybrid for the sake of experimentation and prolonging the Dalek species. Which in turn he became kind, rational, and outright resented what he used to be. The other Daleks didn't take that very well.
* ''Series/{{Dollhouse}}'': In "Instinct" Echo is programmed to believe she is a mother with a baby, not only with her memories but also her glands to induce lactation and parental bonding. Thus, even after Echo's memories are wiped, she still instinctively [[MamaBear seeks out the baby to protect him]].
* It's implied in ''Series/TheFlash2014'', and confirmed in a deleted scene, that Eobard Thawne [[spoiler: TookALevelInKindness to some extent and became more mellow in his Harrison Wells disguise because he used DNA harvested from the real Wells. Future incarnations of Thawne still have the Wells disguise, but are more openly evil and violent]].
* A crossover episode of ''Series/KamenRiderGaim'' feature the story of [[EvilGenius Ryoma Sengoku]] who placed his brain into the robotic body of [[Series/{{Kikaider}} Hakaider]] which ended up making him behave more and more AxCrazy. Something that he found out much to his horror when he returned back to his human body.

** In a reverse example, Ensign Lindsay Ballard is unable to reintegrate back into her life on ''Voyager'' after having been transformed into an alien.

* In ''Webcomic/GunnerkriggCourt'':

[[folder:Web Original]]
* In the Literature/WhateleyUniverse, most of the main characters underwent {{Gender bender}}s when their powers manifested; apparently turning a happy boy into a girl doesn't cause gender identity disorder and since the UnfortunateImplications are glossed over (they get therapy, but it's off screen) to the point you'd rarely realize they hadn't been a girl all their life.

** Its actually specifically mentioned in a few of the original stories (such as Fey 1) that being an Exemplar (Mutant with MostCommonSuperpower as an actual power) specifically invokes this trope. That is to say that as a rule, if you are shape-changing due to being an Exemplar, eventually you'll get used to your new body -- no matter if it's female, a mutant T-Rex, or a giant piece of sentient coral. The fact that [=BITs=] are generally based on the Exemplar's subconscious idea of a perfect body also helps.

* In ''Literature/BusterGirls'' being transformed into a Heartless or one of their minions usually includes a full personality shift to fit their new form more (assuming there's even a personality left).
* ''Roleplay/EquestrianLegends'' has Meadow. Formerly a pony, now a dragon, and with powerful instincts.
* The various characters who transform in ''WebVideo/TheCartoonMan'' saga not only undergo physical changes, but begin acting like cartoon characters as well.
* [[http://kdingo.net/champ/pics/main.php?g2_view=core.DownloadItem&g2_itemId=6184&g2_serialNumber=4 This]] short comic shows off the consequences of Ganon possessing Zelda in ''VideoGame/TheLegendOfZeldaTwilightPrincess''.
* In ''WebOriginal/LinkAndMage'' being physically transformed into a Familiar by a Witch comes with the fitting mental change. In regards to the main characters their outfits show the amount of control a Witch has over them. Once their outfit has fully turned into that of a Familiar, they're also fully under the control of the Witch.

* In ''WebVideo/MyLittlePonyTotallyLegitRecap'', Twilight's sudden infatuation with a guy she barely knows, is explained as her being in the hormonal body of a teenager in an (in the creator's opinion) Anime esque world is affecting her so much, she has to consciously fight her desires not to just bone him on the spot. [[spoiler: She fails.]]
* In ''WebVideo/CriticalRole'', use of the Polymorph spell is limited by the fact that, unlike with Wild Shape, anyone who is Polymorphed also inherits the ''mental'' statistics of the creature they transform into. Perhaps the most famous example is when Jester is sent to spy on a secret meeting while Polymorped into a moth... but because moths have an Intelligence score of ''1'', she has to roll an Intelligence check to see if she even remembers what she was supposed to be doing. When she finds that she can't actually get into the room because the curtains are drawn, she spends the rest of the spell's duration chewing on said curtain, followed by her falling out of the window once she turns back into her normal self.
** Later in the second campaign, Caleb, Jester and Reani are sent to spy on a house while transformed into bats, but while Reani's Wild Shape allows her to retain her mental status, Caleb and Jester are stuck with an Intelligence of 2. Caleb, who is otherwise the most intelligent member of the group, is hit especially hard by this, as his first course of action is to [[ItMakesSenseInContext check the roof for bread]].

For the exact opposite effect, where the body is a plaything of the mind, see YourMindMakesItReal and some forms of EmpathicShapeshifter/SelfPerceptionShapeshifting.

For the exact opposite effect, where the body is a plaything of the mind, see YourMindMakesItReal and some forms of EmpathicShapeshifter and SelfPerceptionShapeshifting.

For the exact opposite effect, where the body is a plaything of the mind, see YourMindMakesItReal and some forms of EmpathicShapeshifter.

* In ''WebOriginal/BusterGirls'' being transformed into a Heartless or one of their minions usually includes a full personality shift to fit their new form more (assuming there's even a personality left).

* The changes in behavior and personality caused by anti-depressants and other psychiatric medications, lobotomies, and brain injuries attest to how changes in the brain can cause sometimes major changes in the mind. All sorts of odd quirks and personality changes caused by brain disorders that go away if those disorders are ameliorated, a nice person becoming a cranky one under the influence of stress (or other) hormones, a [[StepfordSmiler cheerful]] GenkiGirl who [[{{Determinator}} endured]] tons of BreakTheCutie becoming paranoid and bedridden when they get old enough for clinical depression [[TraumaCongaLine to kick in]]. it's very well demonstrated that the personality is a creation of the physical structure of the brain, and even minor physical and chemical changes can turn someone into a very different person, ''forget'' turning into a different species. There's also puberty, [=PMS=], or menopause, all of which tend to induce mood swings ranging from inconvenient to debilitating.

** In [[WesternAnimation/Ben10 the original]] series, the ''primary'' purpose of Ben's Greymatter form is to make him intelligent. Ben also says Ghostfreak made him feel weird, [[SuperpoweredEvilSide for a good reason.]]