History Main / NinetyPercentOfYourBrain

* It is implied in ''Phenomenon'' that the incredible mental and psychic abilities John Travolta's character, George, suddenly gains after seeing a strange light in the sky is caused by [[spoiler:a tumor spreading across his brain and activating unused parts of it. Also, killing him.]]
* In ''Defending Your Life'', everyone on Earth is said to use 3-5% of their brains. When a person dies and goes through the CelestialBureaucracy, they have the chance to [[AscendToAHigherPlaneOfExistence move up to the next level]], where it's possible to use more of their brain. Then after that lifetime, they have the chance to move up to the next level and so on; each level allows one to use more and more of one's brain, which means being more intelligent and less afraid.

* In ''Film/MyFavoriteMartian'', Uncle Martin states that Martians earn their powers from fully using their brains. Tim disagrees, and the reply is "Your astronauts pee in their spacesuits. Case closed".

* [[Literature/TortallUniverse Daine]] makes a reference to this in Wolf-Speaker while sharing the mind of a wolf whose brain was changed by association to her magic: "Numair had said, in an anatomy lesson, that humans used little of their brains... For Brokefang the difference was that each nook and cranny of his skull was packed with ideas."

* In {{Isaac Asimov}}'s ''Pebble in the Sky'', the main character, who has inadvertently been pushed forward from our time to that of the novel, during the Galactic Empire period that leads up to the Foundation books, gets an experimental "Synapsifier" treatment in the hope it will help him learn the language. It does that and more ... he starts becoming telepathic, and strongly enough so that at one point he kills one of the bad guys that way, without even intending to.

* In ''Manga/DragonBall'', all humans have the potential to fly and shoot energy beams - if they are lucky enough to find someone who can teach them how to use Ki energy. In ''Main/DragonBallOnline'', set more than 200 years after the main series, this happened with the book "Groundbreaking Science" written by Gohan, explaining Ki manipulation to the general public.

* The main plotline for an episode of ''Series/HoneyIShrunkTheKids''. To make matters more silly, accessing the other 90% gave the character in question godlike powers. All this was caused by a device that was established in a previous episode to be used for [[FreakyFridayFlip brain-swapping]].
* In ''Series/StarTrekDeepSpaceNine'', this is cited as why Dr. Bashir can lose a portion of his brain and be completely fine. (This was before Bashir was {{Retcon}}ned to be superintelligent.)

* Referenced episode 5 of Series/AlmostHuman where an alleged [[ISeeDeadPeople spirit medium]] says her powers are the result of the Cerebellax procedure, which enhances use of brain pathways.

* The famous [[http://en.wikipedia.org/wiki/Phineas_Gage Phineas Gage]] had a railroad spike driven through his brain, causing massive damage to his frontal lobes. He recovered and his memories and abilities were intact, but his friends said he was "no longer Gage" - he lost his moral compass and [[{{TookaLevelinJerkass}} was much more irritable, profane, and dishonest]]. As the frontal lobes control your personality, this isn't surprising.

* In Stephen King's ''{{Cell}}'', the people who are hit by the Pulse lose almost all of their higher level reasoning skills. After this, [[spoiler: they slowly regain higher level thought, but they use unusual parts of their brain to do it, resulting in them developing telepathy and eventually telekinesis]]. Granted, this is just a theory in-Universe, but the "we only use ten percent of our brains" myth gets thrown around a lot by some highly educated people.

* ''[[TabletopGame/TrinityUniverse Aberrant]]'' uses this as part of the MetaOrigin for novas. Most humans have an underdeveloped, uncharted node in their brain that maps the background forces of the universe. When a nova Erupts, this node becomes active, allowing for limited manipulation of reality -- a.k.a., superpowers.

* Played straight in ''[[LightNovel/ACertainMagicalIndex To Aru Majutsu no Index]]'' as the eponymous character can only retain 1 year of memory in her mind, because 85% of it is taken up with an eidetic recollection of the [[NeuroVault complete contents of 103,000 spellbooks]]. [[spoiler:That is, until it gets subverted with a sledgehammer when a professor reveals that the "15% left over for a year's memories" is complete BS and ''gives a proper explanation of how the mind works'' in the series. Cue CrowningMomentOfAwesome as the hero realizes that he's been played for a sucker.]]

* [[http://www.scp-wiki.net/scp-1475 SCP-1475]] of the Wiki/SCPFoundation gave himslef a [[DisposableSuperheroMaker non-reproducible drug]] that lets him use 100% of his brain 100% of the time. This not only gave him [[MasterOfYourDomain complete control over his body]], but let him rewire his brain so that [[TheSleepless he doesn't need to sleep anymore]]. However, in a true case of BlessedWithSuck, this completed destroyed his autonomic nervous control (that is, the body's ability to automatically regulate the heart/lungs/etc), so he has to spend most of his concentration on keeping himself alive. Not only does this not leave him much concentration to use his voluntary muscles, he's also suffered permanent damage to a lot of his organs due to having messed it up in the past.

-->'''Guy Who Is Probably God''': Listen, it would be a disaster if humans used all of their brains[[hottip:*:see above]] -- Einstein got 20% more[[hottip:*:impossible for obvious reasons, although there were ''some'' anatomical and cellular oddities with his brain; also, while Einstein was pretty damn smart, ''three times'' more intelligent than the average person is kind of pushing it]] and he accidentally drew the roadmap that led to nuclear weaponry[[hottip:*:Oy. First, Einstein's theories had actually very little to do with nuclear fission - they explained why there was a lot of energy available, but the majority of the science behind nuclear weapons came from Becquerel, the Curies, Bohr, Fermi, Meitner, Frisch and Szilard, and Einstein wasn't even on the Manhattan Project or any other experiment into nuclear fission. Also, Einstein ''deliberately encouraged'' the initial development of the atomic bomb as a deterrent against the Nazis, who were also working on their own A-bomb project; it should be stressed that he was horrified when the bomb was actually used, especially since he'd visited Hiroshima before the war.]].

* ValiantComics invoked this with the [[{{Mutants}} Harbingers]], people with StockSuperpowers. Unlike their equivalents in some other comic universes, Harbingers are not physically different from other humans. Elevated levels of activity in their brains result in [[PsychicPowers psionic abilities]] that give them their powers. Ordinary humans can duplicate Harbinger powers through the use special cybernetic brain implants.

* Johnny's powers in the television version of ''TheDeadZone'' come from the fact that a normally unused part of his brain became active to compensate for a damaged section.

* [[http://www.scp-wiki.net/scp-1475 SCP-1475]] of the Wiki/SCPFoundation gave himslef a [[DisposableSuperheroMaker non-reproducible drug]] that lets him use 100% of his brain 100% of the time. This not only gave him [[MasterOfYourDomain complete control over his body]], but let him rewir his brain so that [[TheSleepless he doesn't need to sleep anymore]]. However, in a true case of BlessedWithSuck, this completed destroyed his autonomic nervous control (that is, the body's ability to automatically regulate the heart/lungs/etc), so he has to spend most of his concentration on keeping himself alive. Not only does this not leave him much concentration to use his voluntary muscles, he's also suffered permanent damage to a lot of his organs due to having messed it up in the past.

* In a statement that impressively manages to be wrong ''in every particular'', ''ComicBook/{{Marville}}'' gave us this:

* The famous [[http://en.wikipedia.org/wiki/Phineas_Gage Phineas Gage]] had a railroad spike driven through his brain, causing massive damage to his frontal lobes. He recovered and his memories and abilities were intact, but his friends said he was "no longer Gage" - he lost his moral compass and was much more [[{{Jerkass}} irritable, profane, and dishonest]]. As the frontal lobes control your personality, this isn't surprising.

* In ''ChaosHead'', Norose muses that Gigalomaniacs use the remaining 90% of their brain unlike normal humans, and this is responsible for their abilities. And possibly even worse, it's also stated that 80% of the brain is used for processing visual data.

* Played straight in ''ToAruMajutsuNoIndex'' as the eponymous character can only retain 1 year of memory in her mind, because 85% of it is taken up with an eidetic recollection of the [[NeuroVault complete contents of 103,000 spellbooks]]. [[spoiler:That is, until it gets subverted with a sledgehammer when a professor reveals that the "15% left over for a year's memories" is complete BS and ''gives a proper explanation of how the mind works'' in the series. Cue CrowningMomentOfAwesome as the hero realizes that he's been played for a sucker.]]
* ''MobileSuitGundam'''s Universal Century:
** ''CharsCounterattack'' (where it is mentioned) may use this explanation for why [[PsychicPowers Newtypes]] exist--that people used only a part of their brains on Earth, and began to use the rest after moving into space. However, it was said to be "half" of the brain being used, not 10%. Also the conversation was between a couple of teenagers, so they may simply not know what they're talking about (they also take a fairly romantic interpretation of the idea/purpose of Newtypes, which Gundam [[SlidingScaleOfIdealismVersusCynicism goes back and forth on)]].
** This first appeared in the writings of Zeon Zum Deikun, inventor of the Newtype concept, in the ''MobileSuitGundam'' novelizations.
** This is in turn based on the writings Timothy Leary, specifically the 8-Circuit Model of Consciousness which predicted that people's brains would develop in new ways in the future, becoming more enlightened to cope with the challenges of space travel.
* The foundation of superpowers in ''{{Needless}}''.

* This is part of the premise for ''{{Psyren}}''. Like many others, this explains psychic powers, though they seem no less limited than any other set of superpowers in other series.

* According to Todd Ingram in ''ScottPilgrim'', ninety percent of your brain is filled up with curds and whey. Hence his [[ItRunsOnNonsensoleum telekinetic vegan power]]. Arguably an aversion, though, as Todd is shown to be the dimmest and least imaginative of the League of Evil Exes. While it is canon that veganism gives psychic powers in the Pilgrim universe, Todd's explanation comes off more like a thinly-veiled insult, and Kim in particular seems skeptical.

* This fake statistic appeared in the ''IronMan'' mini "Hypervelocity", as the AI protagonist was frustrated at being forced to function at a relatively slow "cognitive clockspeed".
* DC Comics villain The Key once claimed to have tapped into "the ninety percent of the brain we never use" via a device he built, which allowed him to devise all manner of amazing plans and schemes. This is an aversion, though, as it also drove him completely mad, leading to the implication that he only THINKS he's tapping into new parts of his brain.
* An odd ''{{Superman}}'' story featured a stand-up comedian having part of his unused brain areas activated in an accident, which gave him telekinetic powers, which he used unconsciously to become a sand-covered monster that tried to amuse people to counter his fear of not being laughed at. He was only cured once Superman used his super laughter so that he could finally hear through all the sand that someone was laughing. Okay?

* This is part of the plot of the 1986 film ''FlightOfTheNavigator'', where a young boy discovers an alien probe had experimented with using the unused ninety percent of his brain for [[NeuroVault data storage.]]

* Richard uses this as an insulting mnemonic device to help ''TommyBoy'' remember the figure 1.5%.

* In ''MyFavoriteMartian'', Uncle Martin states that Martians earn their powers from fully using their brains. Tim disagrees, and the reply is "Your astronauts pee in their spacesuits. Case closed".

* ''{{Inception}}'' says this is why in dreams your brain can work faster, as the majority of your brain's processing ability is devoted to processing sensory perceptions. With the use of shared dreaming technology, the brain can work much faster, allowing for a dreamworld hour to pass in minutes in the real world.
* In ''ScottPilgrimVsTheWorld'' vegan evil ex-boyfriend Todd Ingram claims the source of his psychic powers is that he's able to use more than 10% of his brain because isn't gunked up with all that filthy animal protein. Brain is ''made'' out of animal protein, but given that Todd also says that he does not know the meaning of the word "incorrigible" [[spoiler:and he does not]], this creates [[UnreliableExpositor reasonable doubt of the credibility of his claim]].

* In the film ''{{Limitless}}'', starring Bradley Cooper and Robert [=DeNiro=], Cooper plays a down-on-his-luck writer who takes a smart drug called NZT-48 that allows him to access 100% of his brain as opposed to "the twenty percent", granting him superhuman intelligence and prescience.
* Implied in ''TheShadow'', in the end, the BigBad gets a spike through his head and has to have a part of his brain that "no one uses" removed. It turns out that this was where his psychic powers were located.

* [[TortallUniverse Daine]] makes a reference to this in Wolf-Speaker while sharing the mind of a wolf whose brain was changed by association to her magic: "Numair had said, in an anatomy lesson, that humans used little of their brains... For Brokefang the difference was that each nook and cranny of his skull was packed with ideas."
* The DouglasAdams book ''TheLongDarkTeaTimeOfTheSoul'' plays with this: a character in a coma has a dream in which her mind is represented by an infinite collection of cabin trunks, of which ten percent contain past memories, and the remaining ninety percent contain [[EverythingsBetterWithPenguins penguins]].
* Subverted during the climax of JimButcher's ''[[TheDresdenFiles White Night]]''. Harry Dresden's mental passenger Lasciel temporarily over-clocks his brain in order to gain additional time to react to a threat. It is made clear that this is a very Bad Idea and will likely result in brain damage if done for an extended period of time.

* Artemis' magic in ''Literature/ArtemisFowl: The Lost Colony'' is another case of this trope. Humans lost the kind of brainpower necessary for that long ago.

* Mark [=McHenry=] of ''StarTrekNewFrontier'' could not only use 100% of his brain, he could specify at any given time what percentage of his brain is dedicated to what activity. This is because [[spoiler:Mark isn't quite human, due to his being descended from the Greek God Apollo.]]
* Comes up in ''[[XWingSeries Starfighters of Adumar]]'', but context makes it pretty clear that this is a joke. Wes is known for being somewhat [[{{Manchild}} immature]], and he tells Wedge that he thought he heard something last night, when Wedge was... [[DidYouJustHaveSex getting lucky]].

* In ''{{The Secrets of the Immortal Nicholas Flamel}}'', this is the basis for the idea of having one's powers "Awakened".
* ''TheZombieSurvivalGuide'' makes this same error in comparing zombies' senses to those of humans, speculating that undead without eyes have a "sixth sense" derived from the unused part of the brain. Oh, and it claims that we, the living, only use ''5%'' of our brains, doubling this trope's inaccuracy.
* The DoctorWhoExpandedUniverse novel ''The Gallifrey Chronicles'' comes ''very close'' to getting this right ... but doesn't.

* In ''Discworld/SmallGods'', Terry Pratchett said that the other 90 percent of the brain powers a sort of ''WeirdnessCensor'' so that the fact that the entire world we take for granted is, in fact, amazing, is ignored.

* In ''Beneath The Dark Ice'', the protagonist's superhuman abilities are thought to have come from when he was shot in the head in a way that forced the brain to direct more blood to the areas of the brain with the most 'unknown functions'. How this accounts for super strength and endurance is not obvious.
* The Mule from {{Foundation}} could use an intellect ExplosiveOverclocking power on others (cause intuition and creativity to skyrocket, but has bad effects on the one it is used on). The way it is described, it seemed less about using new parts of the brain, and more about using all of it ''non-stop'' without any chance to rest for weeks on end, but he, himself, mentioned a normally low efficiency (20%) as an explanation. This could be attributed him having "education, that of the tramp worlds, and the backwash alleys of space."

* This is a big part of the plot of the ''MyTeacherIsAnAlien'' series. In the second installment, one boy, a school bully of below-average intelligence, has his brain "fried" to make him a genius and a telepath. In the third, the aliens remove the protagonist's brain temporarily to study it. The reason is that humans have the most powerful, yet under-used, brains in the galaxy, and the aliens are trying to figure out why we suppress our supposedly vast mental powers.

* This is one of the major things that separate immortals like Daetrin from the Marra in ''Literature/TheMadnessSeason''. When Daetrin transforms into a wolf, brain scans show him to have neural processes similar to those of a wolf. When Marra does the same thing, her entire brain is lit up, which the scientists exclaim would be impossible normally.
** No, they were amazed at Kiri's scans because she used only the parts that were needed to keep her body upright and mobile (motor control, autonomics, language processing) and used them extremely intensely. Everything else was left utterly untouched, because non-corporeal entities like the Marra don't need their meat puppets to handle memory and cognition, they do that on their own.

* ''{{Eureka}}'''s scientific adviser was on record as making sure that when that concept was used on the show, the line was "ten percent... at any one time" specifically to dodge this trope.
* ''StargateSG1'' and ''StargateAtlantis'' have several instance where this comes up and is dodged in the same manner that Eureka does -- by upping the percentage used at a time, rather than overall. Increasing the amount used to almost 100% is one of the criteria to AscendToAHigherPlaneOfExistence (or at least, it's required for doing so without somebody who's already ascended helping you).

* Referred to in ''KyleXY''. The titular Kyle has a highly advanced brain, learning to speak in one day, and learning kung fu and Chinese from watching an old Bruce Lee movie. They give him a CAT scan and the scan showed he used 80% of his brain. However, the doctors noted this as strange, citing the problems one would have at 100% brain usage (such as seizures), and wrote it off as a machine malfunction. The audience and the character Josh know it's not a malfunction by being GenreSavvy. It is later shown that if he uses his powers too much, he will get a seizure.

* In ''{{Fringe}}'', the 10% fallacy is averted only to be replaced with a different (even more absurd) rationalization. [[spoiler: A MadScientist several decades in the past developed a drug that prevents babies from losing the natural potential they have at birth.]] In a DoubleSubversion the MadScientist in question fails completely in clinical trials only to be proven right when [[spoiler: Olivia]] develops psychic powers. Maybe.

* In the last episode of ''LoisAndClark'', Dr. Mensa uses the rest of his brain and gets [[MyBrainIsBig an enlarged brain]], the power of mind control and the moniker "Fat Head".

* Parodied in ''ScaryGoRound'', where a man survives having 90% of his brain eaten by a zombie because by incredible coincidence she ate only the 90% that no one uses.
* ''FreakAngels'' seems to be hinting at the fact that they have simply not reached their full psionic potential. Arkady's continual experimentation with her abilities seems to be a testament to this.
* A joke that unfortunately never made it into ''PennyArcade'' but does show up on their podcast uses the concept:

* Parodied in ''AHDotComTheSeries'', episode "The Narcissus Syndrome":

* One source of the myth itself (of many possible ones) is a series of experiments done on rodents in whch the poor creatures had large parts of their brains burned away but could still run a particular maze. However, all this proves is that memory is distributed in the brain rather than localized; the rodents still lost other functions. Besides, mice aren't men.

* As the ''savant'' phenomenon proves, people don't use their brains to their full efficiency. We have potential for far greater mathematical prowess that we normally demonstrate in practice. There have been even a few instances where people have received minor brain damage, and retained most of their faculties quite intact, but gained some ''savant'' like skills such as counting dates hundreds of years forward, although they were not as advanced as full savants. [[IdiotSavant Savantism generally has mental disorders attached and what they're talented at is extremely limited]]. Maybe it's best our brains are a 'jack of all trades' rather than focusing all its time [[RainMan counting cards]]

* May have originated when we only ''knew the function of'' (some small percentage) of the brain, and that got misreported as "We only ''use'' (some small percentage) of our brain." Areas having to do with other than motor control or sensations are now called "association areas", and they have a role in interpreting, integrating, and acting on sensory input in combination with stored memories. Higher brain functions, in other words. In the same way that your house has only a fraction of its rooms being actively used at any given time, only a fraction - a rather large one - of your brain is active at any given moment - but, as with the house, that doesn't mean the rest isn't useful. The history of this trope is fairly well outlined in the free first chapter of [[http://eu.wiley.com/WileyCDA/WileyTitle/productCd-047143499X.html this book]]. Furthermore, Bill Nye (y'know, [[BillNyeTheScienceGuy the Science Guy]]) wrote a fairly accessible essay on the subject [[http://web.archive.org/web/20080506104856/http://encarta.msn.com/encnet/Features/Columns/?article=BNBrainCapacity here]].

* In {{Isaac Asimov}}'s ''Pebble in the Sky'', the main character, who has inadvertently been pulled forward from our time to that of the novel, during the Galactic Empire period that leads up to the Foundation books, gets an experimental "Synapsifier" treatment in the hope it will help him learn the language. It does that and more ... he starts becoming telepathic, and strongly enough so that at one point he kills one of the bad guys that way, without even intending to.