History Main / NinetyPercentOfYourBrain

This trope name comes from the oft-repeated but false assertion that humans only use 10 percent of their brains, a misquote of Dale Carnegie's ''Literature/HowToWinFriendsAndInfluencePeople''.[[note]]"The average person develops only 10 percent of his latent mental ability."[[/note]] In RealLife, we use ''all'' of our brains, just not all at the same time -- in much the same way you don't have every electronic/mechanical item in your home running at all times; you only turn things on when you need to use them. If you ever do find yourself with every part of your brain "on" at once, congratulations; '''''you're having a seizure.'''''

This trope name comes from the oft-repeated but false assertion that humans only use 10 percent of their brains, a misquote of Dale Carnegie's ''Literature/HowToWinFriendsAndInfluencePeople''.[[note]]"The average person develops only 10 percent of his latent mental ability."[[/note]] In RealLife, we use ''all'' of our brains, just not all at the same time -- in much the same way you don't have every electronic/mechanical item in your home running at all times; you only turn things on when you need to use them. If you ever do find yourself with every part of your brain "on" at once, congratulations, '''''you're having a seizure.'''''

This trope name comes from the oft-repeated but false assertion that humans only use 10 percent of their brains, a misquote of Dale Carnegie's ''Literature/HowToWinFriendsAndInfluencePeople''.[[note]]"The average person develops only 10 percent of his latent mental ability."[[/note]] In RealLife, we use ''all'' of our brains, just not all at the same time -- in much the same way you don't have every electronic/mechanical item in your home running at all times; you only turn things on when you need to use them. If you ever do find yourself with every part of your brain "on" at once, [[SarcasmMode congratulations]], ''[[OhCrap you're having a seizure!]]''

This trope name comes from the oft-repeated but false assertion that humans only use 10 percent of their brains, a misquote of Dale Carnegie's ''Literature/HowToWinFriendsAndInfluencePeople''.[[note]]"The average person develops only 10 percent of his latent mental ability."[[/note]] In RealLife, we use ''all'' of our brains, just not all at the same time -- in much the same way you don't have every electronic/mechanical item in your home running at all times; you only turn things on when you need to use them. If you ever do find yourself with every part of your brain "on" at once, [[SarcasmMode congratulations]], ''[[OhCrap you're having a seizure!]]'' Think of it like listening to a concert piano piece - all 88 keys aren't going to be pressed all at once. And if you just looked at a single beat, you could say "Look, the pianist is only using 10% of the instrument!"

** ''Literature/PebbleInTheSky'': The main character, who has [[AccidentalTimeTravel inadvertently been pushed forward from our time]] to the far future setting of the novel, 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. Played with in that novel makes quite clear ''why'' humans only use a small percentage of their brain at any one time (within the context of the setting): [[ExplosiveOverclocking using more is damaging to the person in question]], to fatal levels (partly because once the Synapsifier has been used on a person, the effect is permanent). Evidently those ninety percent are there to keep the brain running for year after year.

This trope name comes from the oft-repeated but false assertion that humans only use 10 percent of their brains, a misquote of Dale Carnegie's ''Literature/HowToWinFriendsAndInfluencePeople''.[[note]]"The average person develops only 10 percent of his latent mental ability."[[/note]] In RealLife, we use ''all'' of our brains, just not all at the same time -- in much the same way you don't have every electronic/mechanical item in your home running at all times; you only turn things on when you need to use them. If you ever do find yourself with every part of your brain "on" at once, [[SarcasmMode congratulations]], ''[[OhCrap you're having a seizure!]]''

* In the film ''Film/{{Limitless}}'', starring Bradley Cooper and Creator/RobertDeNiro, Cooper plays a down-on-his-luck writer who takes a smart drug called NZT-48 that, according to the drug dealer who introduces it to him, allows him to access 100% of his brain as opposed to "the twenty percent", granting him superhuman intelligence and prescience. (Of course, since the dealer is clearly lying about everything else he says about the drug, such as it being "FDA-approved", he was probably just making up whatever he felt would get Cooper's character to take it.)

* ''Film/TheLastMimzy'' does this; their newly-unlocked abilities include telepathy, telekinesis, and super-hearing, as well the ability to control spiders by emitting certain frequencies, to send objects through small warp portals, and to draw ancient patterns without ever having seen or heard of them. In the future, levitation is also a standard part of humanity's milieu.

* The ''Night Head Genesis'' anime states at the start that normal people leave ''70%'' of their brain unused. Once again, this explains psychic powers.

* In an episode of ''Manga/KatekyoHitmanReborn'', Reborn gives Gokudera an unique brand of TrainingFromHell by making him eat ramen while withstanding I-pin's Gyoza-ken. Reborn's technical explanation is that, since the Gyoza-ken affects directly the brain, the fact of being able to eat ramen while resisting the muscular spasms the technique provokes would force Gokudera to use all of his brain capacity (whose standard usage is defined here as 30%).

* ''Manga/{{Naruto}}'' does this, but with the chi-like chakra instead of brainpower. Rock Lee's ace in the hole is the ability to open various chakra gates that act like dams for the stuff, with opening enough of them putting him in a [[Anime/DragonballZ Kaio-Ken]]-esque SuperMode. The catch is that, if a ninja opened all the gates, he would suffer from a fatal HeroicRedRingOfDeath.

** ''Literature/PebbleInTheSky'': The main character, who has inadvertently been pushed forward from our time to that of the novel, 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. Played with in that novel makes quite clear ''why'' humans only use a small percentage of their brain at any one time (within the context of the setting): using more is damaging to the person in question, to fatal levels (partly because, as opposed to the Mule's power mentioned below, once the Synapsifier has been used on a person the effect is permanent). Evidently those ninety percent are there to keep the brain running for year after year.

* ''Series/BirdsOfPrey'': Barbara claims that ordinary humans use only five percent of their brains, but metahumans far more. Dinah uses fifty percent, her scans reveal.

** Spoofed in the Italian satirical comedy ''Film/ItalianoMedio'', itself based on a sketch by the same creators. A clever but insufferable man is convinced by his friend to take a pill that reduces his brain capacity to ''2%'', to make him complain less and enjoy life more.
* Implied in ''Film/TheShadow'', in the end, the BigBad gets a glass shard 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.

* In ''Literature/DiaryOfAWimpyKid: Double Down'', Greg hears that humans only use 10% of their brains. He hopes that people don't figure out how to get the last 90%, imagining it being complete chaos.

* Discussed and defied in ''Series/{{Limitless}}''. [[spoiler:Brian attends a party where everyone there is on low-grade NZT]]. He hears someone saying that you only use ten percent of your brain and that the pill works by allowing you to use more. Brian responds by point out that it's a myth.

* [[http://www.scp-wiki.net/scp-1475 SCP-1475]] of the Wiki/SCPFoundation is a deliberate {{Deconstruction}} (the author even flat-out stated that his inspiration for writing it was his [[PetPeeveTrope hatred of this trope]]). He gave himself 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.

* In ''Franchise/ArchieComics'', Archie recites this statistic to his friends. [[TheDitz Moose]] exclaims that 10% is "almost less than half our brains". Archie muses if the statistic is too high in some cases.

* ''Franchise/AssassinsCreed'' has Eagle Sense and Eagle Vision. It lets the user make out if the people surrounding them are friends, enemies or targets. The science behind it all is that [[spoiler: humans were created by a race of other beings and then cross-bred when the other race went extinct. Every human has a certain concentration of DNA from those beings and the higher it is the higher this sense is developed]]. Most people aren´t aware of this ability but it can be awoken through [[spoiler: reliving memories of an ancestor]]. The sense can range from simply seeing people in blue, red, yellow when standing still over being able to walk around while doing it to seeing the paths people went as colored lines.

Compare UninhibitedMusclePower, where powers activate the unused muscle potential instead of unused brain potential. For exceeding the limitations of the body to epic effect, see CharlesAtlasSuperpower. Also see PinealWeirdness, which tends to show up in similar places. Very prevalent in SciFi as a common trope with mentalists and [=ESP'ers=].

* 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.

** "[[Literature/{{Foundation}} The Mule]]": Part of the EmotionControl powers that the Mule had was to [[BottledHeroicResolve cause intuition and creativity to skyrocket, at the expense of their lives]]. He describes human brains as normally operating at 20% efficiency (essentially failing to use 80%), and he can use his power to force all of it to work ''non-stop'' without any chance to rest for weeks on end.

* Mentioned in David Gerrold's novel ''When Harlie Was One'' as the supposed "reason" why the sentient computer of the title, despite being like a human brain, is so much more efficient.
* In the short story [[http://sfreader.com/contest-2008-1.asp "On a Clear Day You Can See All the Way to Conspiracy"]] by Desmond Warzel, a caller to a radio show invokes the "ten percent" myth and the host smacks him down, even giving the "seizure" explanation mentioned in the introduction above.

* In Creator/DanielPinkwater's ''Alan Mendohlson, the Boy from Mars'', the Klugarsh Mind Control course claims that only 10% of your brain is in use, and that the secret to telepathy, telekinesis, etc is learning to access the rest of your brain.

* Comes up in ''[[ComicBook/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]].
-->'''Wedge''': "That old lack of oxygen thing will get you every time. How much brain damage did you suffer? [...] And, more importantly, was it to any of the parts of your brain that you use, or was it in the majority portion?"

The origin of the myth may not even have anything to do with these facts about actual brain activity. It may be a distorted version of the more plausible claim that we only use a fraction of our total ''mental capacity'', ie. we could potentially learn things more effectively and stuff. However, even in this context, the number "10%" is completely arbitrary (in other words, a statistic Dale Carnegie just pulled right out of his ass).

The origin of the myth may not even have anything to do with these facts about actual brain activity. It may be a distorted version of the more plausible claim that we only use a fraction of our total ''mental capacity'', ie. we could potentially learn things more effectively and stuff. However, even in this context, the number "10%" is completely arbitrary, bordering on TwentyPercentMoreAwesome.

* The Stone Mask-created [[OurVampiresAreDifferent vampires]] in ''Manga/JoJosBizarreAdventure'' gain their power through the activation of unused parts of the brain via acupuncture. This awakens the human's evolutionary potential (with abilities like WallCrawling, liquid eye beams, superspeed/strength, regeneration, sucking blood through their fingers, and creating zombies) and it inverts the lifeforce energy in their bodies (making them undead-like beings weak to sunlight and [[BattleAura Ripple]], the amplified essence of life). They were created by Mayan warriors called the Pillar Men to become "the ultimate lifeform." [[spoiler:The one used by Dio is an imperfect prototype and merely unlocks about 90% of that potential. A more powerful one was used by the Pillar Men, who can consume anything that directly touches them while also having nearly complete control of their bodies but are still weak to sunlight. Kars, their leader, eventually uses one that unlocks 100% of the brain's potential, thus making him immune to Ripple and sunlight.]]

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