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?

  • 2
    I additionally recall that this claim is often attributed to Einstein.
    – Lagerbaer
    Commented Apr 14, 2011 at 18:02
  • 1
    @Chris - your bounty request doesn't make sense: all parts of the brain have different functions. While not all are used at the same time, all have a use. Thinking of brain capacity is misleading.
    – Sklivvz
    Commented Aug 2, 2014 at 23:40
  • I've heard a computer keyboard analogy - we only use a small percentage of it at a time, but if you tried to use every key at once you'd just get noise. Commented Jul 22, 2015 at 5:47
  • As mentioned in several of the answers, that attributes more to active neurons, but there are a lot of brain structures that are more "support" than neuron-firing in their roles. So, really, a large percentage of the "inactive" brain could never be active if it were just about the neurons, so that would also be a poor mapping to capacity. Sadly, we get tripe like the movie "Lucy" based on this, which was more off-putting in terms of pseudo-scientific blargle/hokum than even the original Superman making time go backwards by flying against the rotation of the Earth a bunch of times. Commented Oct 3, 2016 at 13:44
  • I think that 10% or even 5% thing is in relation to conscious and subconscious minds and by saying our conscious mind is like only 5 or 10% of the total is the reason for 10% myth. And as we know many people confuse mind and brain.
    – Rolen Koh
    Commented Jun 13, 2017 at 6:41

3 Answers 3



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.

  • 1
    Is there any research or indication of what percentage of our brain we do use, or is that not measurable? Commented Feb 25, 2011 at 4:02
  • 1
    The wikipedia article mentions that there are PET and fMRI studies which show activity in all parts of the brain.
    – ericg
    Commented Feb 25, 2011 at 4:09
  • 22
    @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. Commented Feb 25, 2011 at 4:55
  • Brain power here would mean the potential not physical parameters. It is not saying 10% active , which is prima facie false.
    – user11777
    Commented Jun 8, 2015 at 8:43
  • @skept101 - That's where the false claim comes from - people conflating/confusing physical parameters and activity with "computing" potential. There are a significant amount of the tissue or structures that act more in a support kind of role, so people naturally assume that "inactive" brain matter can somehow be activated like the neurons that fire during cognition. There have been a lot of bad movies made on this particular myth. "Lucy" is the most egregious one that comes to mind for me. Commented Jul 2, 2020 at 13:28

Two more references:

Dr Karl

The myth that we use only 10% of our brain is finally being proved untrue, because over the last few decades, we have invented new technologies (such as Positron Emission Tomography and Functional Magnetic Resonance Imaging) that can show the metabolism of the brain. In any one single activity (talking, reading, walking, laughing, eating, looking, hearing, etc) we use only a few per cent of our brain - but over a 24-hour day, all the brain will light up on the scan.

Straight Dope

Obviously not all the brain is in use at once. At any given time about 5 percent of the neurons are active, the only sense in which the old saw is even close to true. (Good thing, too, or you'd have the equivalent of a grand mal seizure, a mental electrical storm in which all the neurons fire continually.) The parts of the brain are highly specialized, and some areas are more active than others depending on the task at hand. But all the parts do something, and it seems safe to say that over time you use pretty much all your brain, just as most people use all their muscles to some degree.

This one is a definite no.


The 10% statistic is a myth. Mythbusters tested, and it is closer to 30% at a given instant, although all parts of the brain are used over a longer time period.

While hooked up to a magnetoencephalogram (MEG), a neuroimaging device that measures magnetic fields produced by the brain's electrical currents, Tory exercised four different neurological regions with memory drills, math calculations, word associations and image comparisons. Over the course of the MEG exam, around 35 percent of Tory's brain jumped into action, busting the brain myth.

Cognitive enhancing drugs similar to "NZT-48" are quite real though, an example being a drug called PRL-8-53.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .