Vote in current poll

Read the 30 psychobabble phrases then vote for the one you find most irritating.

Seriously, Would You Admit to Only Using 10% of Your Brain?

Cycling

Mind-myth 1: Like many of the myths now seemingly fuelled by New Agers hoping to unlock the untapped, hidden forces that will unleash previously unimagined human potential, the 10% myth is a slippery customer.

Just when all the evidence has been marshalled against its original incarnation, showing that, yes, actually we do physically use all our brains, it turns out 'human potential' can't be measured empirically. Apparently the unused 90% is hidden below the surface, out of sight and almost out of mind. Which is convenient.

Let's start at the start.

The idea that we only use 10% of our brains is probably such an enduring myth because it's comforting to think we have spare capacity. The 'unused' 90% could take up the slack after brain injury or offer the possibility for miraculous self-improvement. This flexible factoid has been used not only to sell products to enhance our brain's performance, but also by psychics like Yuri Geller to explain mystical cutlery bending powers.

Boring, tedious, but unavoidable facts


Unfortunately there's four good reasons it's almost certainly false (Beyerstein, 1999):
  1. If we only use 10% of our brains then damage to some parts of our brains should have no effect on us. As any neurologist will tell you, this is patently not true.
  2. From an evolutionary perspective it is highly unlikely we developed a resource-guzzling organ, of which we only use 10%.
  3. Brain imaging such as CAT, PET and fMRI shows that even while asleep there aren't any areas of our brain that completely 'switch off'.
  4. Parts of the body that aren't used soon shrivel and die. Same goes for the brain. Any neurons we weren't using would soon shrivel and die.

The structure of the brain and its metabolic processes have also been carefully examined, along with the diseases that afflict it. None of this work has suggested there is a hidden 90% that we're not using. Unfortunately.

Anyone who still maintains we only use 10% of our brains after this fusillade of fact has to come up with a counter-argument for each one of these. Actually, you might argue that imaging technology is rubbish or the neurons are only working at 10% capacity, but refuting all four, taken together? Now that's tricky.

Mythical roots


The roots of this myth are very difficult to discern, probably because there are so many different, diffuse stories about its origin. One probably apocryphal story is that Einstein once explained his brilliance - compared to the rest of us mere mortals - by saying he actually used more than 10% of his brain (Wanjek, 2003). Despite probably being based on a misquote, the repeating of this story can't have hurt the myth's power.

Perhaps some of the earliest roots of the myth come from work by physiologists in the 1870s. They routinely applied electrical currents to the brain to see which muscles moved. They found that large parts of the human brain could be zapped without any corresponding bodily twitching. This led them to dub parts of the brain 'silent'. But they didn't mean silent in the sense of inactive, just that it didn't make any muscles move. Of course this didn't stop the phrase being misinterpreted.

The actual confirmed first written sightings of this myth, though, is in a 1940s advert for the book Cold Comfort Farm by Stella Gibbons (Wanjek, 2003, p.21):
"What's holding you back? Just one fact -- one scientific fact. That is all. Because, as Science says, you are using only one-tenth of your real brain-power!"

Whatever its provenance, the 10% myth is certainly a slippery customer. The reason is two-pronged: first, it's impossible to prove something doesn't exist and second, people like to believe it. If I say I've seen a Pegasus, or visited Mars, or that all our brains have huge untapped potential, you can't definitively prove me wrong. That's why, despite a few good solid blows to the head, this myth refuses to go down.

Perhaps putting it the other way around might deliver the knock-out blow. Instead of talking about the 90% of untapped potential, just ask people why they only use 10% of their brains. Would anyone seriously admit to that? I, for one, am working at maximum capacity. Well, most of the time anyway...

» Find out if any other mind-myths catch you out.

» If you enjoyed this post, subscribe to PsyBlog (RSS).

[Image credit: Clint M Chilcott]

References

Beyerstein, B. L. (1999). Pseudoscience and the brain: tuners and tonics for aspiring superhumans. In: S. Della Sala (Ed.). Mind myths: Exploring popular assumptions about the mind and brain. London: John Wiley & Sons.

Wanjek, C. (2003). Bad medicine: misconceptions and misuses revealed, from distance healing to vitamin o. London: John Wiley & Sons.

Labels:

23 comments

Anonymous Lirone on 11/2/08 12:27 PM 

I'm reminded of a Douglas Adams quote... after an explosion someone is in hospital and dreaming/hallucinating cabin trunks full of penguins. On coming round, she reflects that she had heard that we only use 10% of our brain but had no idea that the other 90% was used for storing penguins :)

(As this is my first comment on your blog, thought I'd say thanks for all the thought-provoking material!)

Blogger Michael Meadon on 11/2/08 1:52 PM 

Good post. There seems to be quite a bit on the 10% myth recently, any reason for this? (Sciam Mind, for example: http://www.sciam.com/article.cfm?id=uncovering-brainscams&print=true). This same article attributes the myth to a misunderstanding of William James's writings.

Blogger Jeremy (PsyBlog author) on 11/2/08 2:06 PM 

Lirone, you're welcome! Good quote too - from The Long Dark Tea-Time of the Soul I think.

Michael, thanks for the link - I hadn't seen this. I did, however, come across the William James connection along with a few others which I don't mention.

Not sure why this a particularly popular topic at the moment. I think debunking these sorts of myths is always popular because it's the kind of thing that comes up in conversation and people like to argue about.

Blogger HoverHell on 11/2/08 5:15 PM 

I'd mention few things I stumbled upon before.
First, it might be that 90% refer not to some parts of brain, but well-spread across entire brain. (There was evidence on non-disabled quite average man with brain mostly filled with some liquid.... I'm not sure I can find the link now, though).
Second, it's more probably that we use 10% of brain _most_ time, e.g. we almost never use entire brain at once. And that we don't use brain most of time, because it will lead to neural exhaustion.
P.S. That's just my thoughts and unproved memories, so...
P.P.S. and excuse my bad english...

Anonymous Ian Kemmish on 11/2/08 5:32 PM 

Fight myth with myth. One good riposte is "well, just be grateful, because if you were using 20% of your brain at the moment, you'd be lying on the floor having an epileptic fit."

This is not original, but sadly I can't remember to whom I saw it attributed.

Anonymous Mindfulness on 11/2/08 8:54 PM 

I think the statement should read: "we only use 10% of our brain consciously". And then it will become closer to the truth.

Regards,

Olivier.

Blogger Jeremy (PsyBlog author) on 11/2/08 9:08 PM 

Hi Olivier, that is just a different version of the same myth. There's no evidence that our unconscious minds are only working at 10%, just the same as there's no evidence our conscious minds only work at 10%.

Anonymous Chris Marshall | Martial Development on 12/2/08 2:03 AM 

If we only use 10% of our brains then damage to some parts of our brains should have no effect on us.

This statement is completely irrational. Consider a fishing net, 1000 sq.ft. in size. Cut a 10 sq.ft. hole in that net.

This mere 1% change to the net's overall integrity will have a drastic effect on your haul.

Brain imaging such as CAT, PET and fMRI shows that even while asleep there aren't any areas of our brain that completely 'switch off'.

Another creative interpretation of scientific fact.

Instead of the fishing net, consider the pipelined architecture of modern CPUs. If you disable pipelining and measure its performance from the outside, using equipment of comparable accuracy and precision to an fMRI machine, you will find that no areas are "switched off". Then turn on pipelining, and measure again. Still, no areas are "switched off", yet its performance has improved.

How is this possible? It's a combination of measurement error and faulty interpretation.

"Facts" #2 and #4 have their own problems.

Let's get our own house in order, before we start picking on those silly New Agers. ;)

Blogger Subconscious Mind on 12/2/08 5:08 AM 

Thanks for the great and motivating post! I fully agree with you. Do check out http://www.subconscious-mind.org, they have a whole host of interesting and helpful articles.

Anonymous Rob Malvern on 12/2/08 8:14 AM 

I'd always assumed that the whole 'only use 10%' thing actually meant that you only used 10% at one time. So you would use all of your brain, just not all at once.

Anonymous Yeo Zhiyuan on 12/2/08 8:40 AM 

Hi Jeremy,

Yes, i think this is a myth. Or perhaps it is due to translation error, whatever.

I read it somewhere before that only 10% of our brain is active at any given time when scanned with MRI, depending on the activity we are doing.

For example, when we are talking, the neuron activities will 'light up' in the language region in our brain and the rest of the brain will go inactive temporary. Then when we switch task, let's say - solving maths, then the language region will go inactive and the logic region will go active instead.

Our brain is functioning this way to prevent process overload. I think we could go crazy if all the regions in our brain light up at the same time. Perhaps this is the same reason why human being can't really multitask, let's say doing 10 things at the same time. We could usually only focus on one or two tasks at any given time. For example, we can't talk and listen simultaneously.

So, yes, the usage of 10% of our brain is not entirely wrong, rather i believe it was a misconception.

Anyway, i thought your blog has some pretty informative content recently. Nice to read them. Keep it up. :)

Blogger Jeremy (PsyBlog author) on 12/2/08 9:09 AM 

Chris, with the fishing net analogy I think you're saying that the bits we 'don't use' might be spread evenly throughout the brain. There's no evidence for that either. (Hoverhell, this is your point as well).

With the CPU analogy you're assuming parts of our brains are switched off. What, sometimes? In some people? Just when they get in a brain scanner?

Remember that you can't prove something doesn't exist. Where is the evidence for us only using 10% of our brains?

Ian, like it!

Rob, Yeo Zhiyuan, these are both creative interpretations of exactly the same myth.

Anonymous Chris Marshall | Martial Development on 12/2/08 8:34 PM 

Jeremy, I am making no assumption about when or whether parts of the brain are switched off. I am pointing out that the measurement equipment we have today is too crude to gather any useful evidence at all.

"You can't prove I'm wrong" is not science, whether coming from New-Agers or their opponents.

Blogger Jeremy (PsyBlog author) on 12/2/08 8:45 PM 

Chris, apologies if I didn't make myself clear. I meant that anyone who wants to support the idea that we only use 10% of our brains needs to provide some concrete evidence.

Point taken about fMRI etc. Compared to future imaging technologies, it is probably relatively crude.

Anonymous Anonymous on 13/2/08 7:04 AM 

It is 10% by weight. The neurons are only a small part of the brain. Like the rest of body a majority of the brain is Water. Blood, vessels, waste removal, etc. add more. So you can you only use 10% of your brain, but if you took out the water it wouldn't work either.
dr Howard

Blogger Eric on 13/2/08 11:49 PM 

I don't disagree with you but, in my opinion, such debates are not scientific at all, and refering to science is just a rhetorical trick. This assertion just lacks definition for all the terms it uses. Building an opinion on such bases is just a question of taste - what position you prefer to defend. Then you are free to twist the definitions to fit your thesis and voilĂ , you are right.

For example, it is almost certain that any single person uses far less than 10% of the biologically possibile states of interconnexions between its neurons, along its life. Does this make the initial assertion true ?

Yet, your arguments are cool to face non-scientific defenders of the 10% use the brain theory defenders.

Blogger Jeremy (PsyBlog author) on 22/2/08 9:41 AM 

Dr Howard, I'm not sure if you're joking!

Eric, as commenters here have so ably pointed out the '10% myth' can be redefined and massaged so that it is true. The myth is badly defined and open to multiple interpretations precisely because it's not based on any science! So, in that sense, I agree with you.

Blogger rhiannon-ruth on 19/4/08 3:35 PM 

I think that Joe public (being one of them lol) are strangely comforted by this theory.. or myth whichever way you prefer! That leaves a good 90% unnacounted for. We are then free to attribute unexplained human behavior down to the grey matter that we no nothing about. Murder, religous zeal, psychic mediums, super human strength. the list goes on... But the truth of the "matter" (haha excuse the pun) is, that although we can now say, "right, this neuron does this...and if we tweak that bit.. we can make him drool.. way hey.." We dont really KNOW. So until every square inch of the brain is accounted for(then we've still got the subconcious brain to think of and the alpha state that pychics believe they can tap into) we cannot completely prove, nor completely dispell the 10% myth.
However.. i personally have never really taken the percentages seriously.. I always believed it just referred metaphorically to the fact that the brain is a complex organ and there may well be things we will never know about the workings within it. :) Brilliant article though, very thought provoking.

Blogger garrett on 6/5/08 4:09 PM 

i'm not sure why nobody has mentioned glia yet, but they seem to be the most likely source of the 10% myth.

From Wikipedia:

"The human brain contains about ten times more glial cells than neurons.[1] Following its discovery in the late 19th century, this fact underwent significant media distortion, emerging as the famous myth claiming that "we are using only 10% of our brain". The role of glial cells as managers of communications in the synapse gap, thus modifying learning pace, has been discovered only very recently (2004)."

This would be a very clear motivation for the myth, and the misinterpretation is also clear--people got the idea that the glia were somehow inert and unimportant, whereas the neurons were being actively used for thinking. now it is recognized that glia cells also perform vital functions.

it's kind of like claiming that we only use a certain percentage of our body for sports, nowhere near our full potential, because we waste space with such things as blood vessels and organs...

Blogger garrett on 6/5/08 4:22 PM 

also, all you need to do to debunk the 10% myth is to say "neurologists and cognitive scientists agree that there is no evidence that we use only 10% of our brain, in any sense"

i think that most people who hear the myth think there is some scientific study out there that supports it. there isn't. basta.

OpenID rufsketch1 on 6/5/08 7:28 PM 

perhaps the myth comes from a misinterpretation of us being conscious of the processes of only a small part of our brain? (we have no clue how exactly we seem to know that one apple is less than two apples, or how all together they make 3 apples).

OpenID chrislehrich on 19/5/08 2:13 AM 

It strikes me that a great deal of the motivation behind this myth is not so much that people believe there is, as one commenter put it, "some study out there that shows" it to be true; rather, many people want to believe that Science (here treated as a monolithic entity) doesn't understand something and doesn't want you to know it.

To expand, then, the myth in one of its classic formulations (e.g. Pauwels & Bergier, Le matin des magiciens [The Morning of the Magicians]) goes something like this:

1) The best neurological information we have today is utterly unable to account for the workings of 90% of the brain. [sort of true, if we're talking about the 1940s or so, if we define things loosely]

2) This means that 90% of the brain's power and potential is beyond the knowledge of science. [rather less true, but still sort of arguable mid-century]

3) This is not because science doesn't know but because science, in its current state, is incapable of knowing these things. [actually quite true, if we take the "current state of science" to mean the technical state of neuroscience mid-century]

4) This is because science refuses to acknowledge that which is beyond its current ken. [exceedingly problematic as a generalization]

5) In fact, science doesn't want you to know about this higher potential. [moving into the insane as a generalization: science is not a continuous entity with a will]

6) This is why science also ridicules things like telepathy, telekinesis, and so on, all of which are demonstrably real. [no, they're not]

7) In fact, these things are done with parts of that special, hidden 90% of the brain, and some people have evolved just a hair beyond the rest of us and can make active use of this portion of the brain. [does not at all accord with the previous, much more limited claims about the 90%]

So it all rests on a crucial bit of fallacious logic:

A) Neuroscientists at X time have an imperfect, incomplete knowledge of the total function and capacity of the brain. [true]

B) That part of the total function which neuroscientists do not fully understand must do something whose very function is outside the normal realm of accepted science. [false inference]

Blogger Kalli on 16/6/08 5:27 PM 

I suspect the original copywriter - or even the original "press releases" about any such findings - confused 'brain' with MIND.

I have no doubt that, as far as it is observable, most people seem to use a minute portion of their mind.

The equation "mind = brain" is the real myth.

And the fact that it still persists to this day is a real tragedy...