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I've heard claims that the average person uses only 10% of their "brain power," whatever that means. The implication, though, is that there the majority of our brain's potential is untapped. However, I've often heard this refrain from people who are selling "training" or "secrets" to unlock the unused potential of our brain.

It seems unlikely that there would be evolutionary advantages to having a brain whose capabilities lie largely untapped.

I'm curious - what percentage of our brain do we use, or can it even be quantified in such measures?

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The other 90% is curds and whey, clearly. –  Shinrai Feb 25 '11 at 15:19
It may be that any particular person is only using 10% of their brain at any one time, but that doesn't mean that they don't use other parts of their brain at other times. As a programmer, it's possible for 10% of my program to be necessary at any one time, but that doesn't mean that the other 90% is useless, it just means it's not currently necessary for the subset of active functions. –  zzzzBov Mar 11 '11 at 16:41
One reason the myth is persistent is Hollywood. In the recent film, the Sorcerer's Apprentice, they used the 10% myth as the reason most people don't have access to their magical powers. It's a cheap plot gimmick that is used over and over –  Nthaoe Mar 11 '11 at 20:20
I've met some people that seem to use less the 10% of their brain. –  hydroparadise Feb 7 '12 at 20:54
The thing that I dislike about the 10% brain myth the most is that it doesn't even make sense. Neurons (in general) encode information as a continuous stream of action potentials, often called spikes. If a neuron is always silent or always spiking, it doesn't convey any information. For example, there is a neuron that will spike like crazy when you feel the bump on the "J" key on your keyboard on a specific location of your index finger and it will be silent when your index finger is raised up from that key. Imagine that this neuron was "using its full potential" and it was always firing, rega –  Jonathan Sep 2 '12 at 18:12
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1 Answer

up vote 66 down vote accepted


I believe snopes.com has some solid information on this topic: The Ten-Percent Myth.

There is also the 10% of brain myth article on wikipedia:

Neurologist Barry Gordon describes the myth as laughably false, adding, "we use virtually every part of the brain, and that [most of] the brain is active almost all the time". Neuroscientist Barry Beyerstein sets out seven kinds of evidence refuting the ten percent myth:

  • Studies of brain damage: If 90% of the brain is normally unused, then damage to these areas should not impair performance. Instead, there is almost no area of the brain that can be damaged without loss of abilities. Even slight damage to small areas of the brain can have profound effects.
  • Evolution: The brain is enormously costly to the rest of the body, in terms of oxygen and nutrient consumption. It can require up to twenty percent of the body's energy--more than any other organ--despite making up only 2% of the human body by weight.[6][7] If 90% of it were unnecessary, there would be a large survival advantage to humans with smaller, more efficient brains. If this were true, the process of natural selection would have eliminated the inefficient brains. By the same token, it is also highly unlikely that a brain with so much redundant matter would have evolved in the first place.
  • Brain imaging: Technologies such as Positron Emission Tomography (PET) and functional magnetic resonance imaging (fMRI) allow the activity of the living brain to be monitored. They reveal that even during sleep, all parts of the brain show some level of activity. Only in the case of serious damage does a brain have "silent" areas.
  • Localization of function: Rather than acting as a single mass, the brain has distinct regions for different kinds of information processing. Decades of research has gone into mapping functions onto areas of the brain, and no function-less areas have been found.
  • Microstructural analysis: In the single-unit recording technique, researchers insert a tiny electrode into the brain to monitor the activity of a single cell. If 90% of cells were unused, then this technique would have revealed that.
  • Metabolic studies: Another scientific technique involves studying the take-up of radioactively labelled 2-deoxyglucose molecules by the brain. If 90 percent of the brain were inactive, then those inactive cells would show up as blank areas in a radiograph of the brain. Again, there is no such result.
  • Neural disease: Brain cells that are not used have a tendency to degenerate. Hence if 90% of the brain were inactive, autopsy of adult brains would reveal large-scale degeneration.

Here is an article from Scientific American: Do we really use only 10 percent of our brains?

and a google search turns up many, many more article which all say the same thing. I couldn't find anything which argued otherwise.

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Is there any research or indication of what percentage of our brain we do use, or is that not measurable? –  Scott Mitchell Feb 25 '11 at 4:02
@ericgorr: It would be nice if you elaborated a bit to bring some of that evidence this site. Simply answering "no" and providing a bunch of links might answer the author's question in the literal sense but it doesn't really add much to this site for other people who come here searching for answers. –  Robert Cartaino Feb 25 '11 at 4:55
@Robert: Providing and answer and supporting evidence does add to "this" site. I'm not sure what value you perceive by needlessly copying and pasting data. –  Russell Steen Feb 25 '11 at 5:32
@Russel: External sites can go away. –  Lennart Regebro Feb 25 '11 at 7:56
@Russel: I agree with @Robert - it would be useful to post some choice quotes from the various sources in your answer. –  Scott Mitchell Feb 25 '11 at 18:33
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