we use 10 percent of our brains

[scamartistry]

This sounds crazy - what gives??

[DaveRaver]

90% is memory storage.

[KneadToKnow]

Cecil's 20-year-old reply

[Great Antibob]

It's a popular enough meme, but it's also absolutely untrue.

Here's a website that goes through some of it:

http://faculty.washington.edu/chudler/tenper.html

[Dereknocue67]

I'm going green! In these tough economic times, I've decided to use less energy and reduce my brain usage to 5%.

[horsetech]

Interesting. How many miles per cheeseburger are you getting now?

[Arkcon]

Originally Posted by scamartistry

This sounds crazy - what gives??

Yep. Presumably, the meme got started by a Theosophist, perhaps saying, "well, most humans use 10% of their brain, but I'm up at 15% and see how awesome I am, gimmie some money and I can take you to 12% overnight" And stupid people (and who isn't a little stupid, at least once in a while,) decided it was worth a shot. I was just a child when I first heard it, and grown ups said it, and I believed it, because ... grown ups said it.

[Chronos]

Yeah, all you can really do is try to guess what grain of truth (if any) it might have been based on, but without tracking down the original source, that's just a guessing game, and it's quite possible that, like most BS, it doesn't have an original grain of truth at all.

[Jragon]

Originally Posted by Chronos

Yeah, all you can really do is try to guess what grain of truth (if any) it might have been based on, but without tracking down the original source, that's just a guessing game, and it's quite possible that, like most BS, it doesn't have an original grain of truth at all.

The only thing I can think of is that perhaps something in the ballpark of 10% is only active at once? That or early neuroscientists looked at half the brain, couldn't find a 1-1 mapping between it and the body and went "wtf is this?" and declared it inactive. (These are total shots in the dark, I doubt they're correct)

[Half Man Half Wit]

Originally Posted by Jragon

The only thing I can think of is that perhaps something in the ballpark of 10% is only active at once?

FWIW, that's what I always thought, and wiki thinks so, too.

[blondebear]

You can get a lot more than 10% if you use NZT.

[orcenio]

One of the most commonly used factoids in my Neuroscience department is that there are 10 times more Glial cells then Neurons in the human brain. A bit a math would show that this puts Neurons in ~10% range. Could be a possible start of the myth...?

(However despite that this factoid is commonly told, this paper seems put the Glial:Neuron ratio to 1:1 or lower.)

[Doctor]

The other 90% is overhead for the operating system!

[Buck Godot]

Originally Posted by Jragon

The only thing I can think of is that perhaps something in the ballpark of 10% is only active at once?

This seems likely to me too. Its the same as saying that a book only uses 10% of its pages because there is more white space than ink covered space. Having a brain that had 100% of neurons firing would be as useful as reading an entirely black page.

[Chronos]

Or it could be referring to the fact that people can lose large portions of their brain and still function. Maybe somewhere, sometime, there was someone who lost 90% of his brain and still survived, thus proving that all that was "unused". The thing is, there are a lot of possible explanations, and no way of telling which (if any) of them was the actual origin.

[code_grey]

Originally Posted by blondebear

You can get a lot more than 10% if you use NZT.

wow, I am sooo there... Check this out:

With NZT you can...

- Master the Stock Market
- Maximize your Physical Strength
- Learn a Foreign Language in a Day
- And So Much More!

Anyway, I have always suspected that the personal coaches industry nowadays is based on some dubious premises. But at least, that industry could hypothetically evolve into something that works, if they put their mind to it. But here we go - why try to improve things that don't work but could have, when you can make plenty of money selling snake oil of the purest sort. Made of real snakes or your money back!

[Lukeinva]

In some cases 10% is a very generous usage.

[Shot From Guns]

You know what we call it when someone uses 100% of their brain all at once?

SPOILER:

A seizure.

[XT]

Mythbusters did an episode on this as well. It was pretty interesting. To give the short answer to the OPs question, it was BUSTED...

-XT

[Chronos]

Did they blow up someone's brain at the end?

[XT]

Sadly, no. They probably blew up something else though...I misremember what the other story line was. On a bright note, though, Kari was wearing a tight shirt and jeans, which is always a high point.

-XT

[ultrafilter]

Originally Posted by xtisme

Sadly, no. They probably blew up something else though...I misremember what the other story line was. On a bright note, though, Kari was wearing a tight shirt and jeans, which is always a high point.

-XT

That probably depressed brain usage pretty hard.

[purplehorseshoe]

*snerk*

Hard.

[Johnny Angel]

Originally Posted by Chronos

Or it could be referring to the fact that people can lose large portions of their brain and still function. Maybe somewhere, sometime, there was someone who lost 90% of his brain and still survived, thus proving that all that was "unused". The thing is, there are a lot of possible explanations, and no way of telling which (if any) of them was the actual origin.

One story I saw years ago claimed that the story originated with a patient who was found to have some kind of swelling in his skull, such that his brain developed occupying about 10 percent of the space a brain would normally occupy, though it was perfectly functional. I think this came up on the Snopes Message board, but I haven't heard about it since.

[Chronos]

On a bright note, though, Kari was wearing a tight shirt and jeans, which is always a high point.

Wouldn't that be two high points?

[XT]

I'm not very good at math, and seeing her in a tight tee shirt that leaves her tummy exposed, and skin tight jeans tends to shut down what little brain power I have as the blood flows...erm, to somewhere other than my brain.

-XT

[Irishman]

Originally Posted by code_grey

But here we go - why try to improve things that don't work but could have, when you can make plenty of money selling snake oil of the purest sort. Made of real snakes or your money back!

Methinks you should listen to the sound of whoosh.

SPOILER:

NZT is a fake drug from the movie Limitless. The protagonist takes it and does all the things listed, then finds out if he quits it will make his brain mush.

I figured the origin was from the early days of brain science, and some scientist's statement about only knowing what 10% of the brain does - you know, "we've only mapped out 10% of the brain yet, but we will keep at it". That got morphed into "we only use 10% of our brains".

But I have no cite.

[Tammi Terrell]

To my mind, the late Barry Beyerstein conducted the best exploration for origins of this belief. His paper, "Whence Cometh the Myth that We Only Use Ten Percent of Our Brains?," is no longer hosted by Simon Fraser University, but it's still available (in PDF form) via the Internet Archive.

http://replay.web.archive.org/200609...t-of-Brain.pdf

[Little Nemo]

Originally Posted by Buck Godot

This seems likely to me too. Its the same as saying that a book only uses 10% of its pages because there is more white space than ink covered space. Having a brain that had 100% of neurons firing would be as useful as reading an entirely black page.

The analogy I've always used is it's like the rooms in your house. You may only be in one room at any given time but that doesn't mean the other rooms aren't used.

[Nametag]

Originally Posted by Tammi Terrell

To my mind, the late Barry Beyerstein conducted the best exploration for origins of this belief. His paper, "Whence Cometh the Myth that We Only Use Ten Percent of Our Brains?," is no longer hosted by Simon Fraser University, but it's still available (in PDF form) via the Internet Archive.

http://replay.web.archive.org/200609...t-of-Brain.pdf

And, for those who don't want to read pages and pages of erudite whining, William James, in a speech to the American Philosophical Association, said something like "the average man develops only ten percent of his latent mental abilities" (the quote is from Dale Carnegie).

Not a word about the brain; he was just saying that people are lazy.

[code_grey]

Irishman, I just read the article http://en.wikipedia.org/wiki/Limitless and cannot even tell what was wrong about the nootropic drug in question. Why didn't the protagonist keep taking it to avoid hangovers? Was it Flowers for Algernon or Pebble in the Sky type of a deal with significantly shorter lifespan for the genius involved?

[njtt]

Originally Posted by Jragon

The only thing I can think of is that perhaps something in the ballpark of 10% is only active at once?

But that is not much closer to being true than the original version. Although the typical fMRI or PET scan (or other brain imaging technique) only shows a fairly small proportion of the brain to be "lit-up" at any one time, it does not follow (and is not the case) that the rest is not doing anything. These imaging techniques show up the most active areas at some point in time, but it does not mean that the rest is not doing anything (or even that it is not doing anything relevant to the current cognitive task).

My WAG as to the origin of the 10% (or whatever other figures you may see quoted) myth is that, not so very long ago, neuroscientists were only able to ascribe definite functions to a small proportion of the brain, and the specific functions of the other parts were essentially unknown. Brain maps from 40 or 50 years ago would have large areas labeled as "association cortex", which meant, in effect, "we don't know what this part is for, but it is probably important for thinking, somehow." The expression "association cortex" still occasionally appears in neuroscience publications, even though functions (often multiple ones) have been attributed to pretty much every tiny bit of the brain by now. Anyhow, it does not seem implausible that someone might confuse "we do not know what 90% of the brain does" (true not so long ago) with "90% of the brain does not do anything" (which no serious scientist ever believed).

[Walther Ego]

I have a vacuum cleaner. I use it 10min/week. I'm not worried.

[Irishman]

code_grey , I'm going to spoiler this, since it's about the movie (even though the link pretty much blows the whole plot.)

SPOILER:

He started taking it, and then started taking it in increased doses, and that caused him to have blackouts and lost time. During one of the blackouts, he vaguely recalls hooking up with a hot chick, who turns up dead, and he's the last person to have been seen with her. So he tries to quit cold turkey, and learns that causes the "hangovers" - migraines and cold-sweats and incapacitating weakness. Then he finds out his ex-wife took the stuff, and she's now a fried out near cripple, because she quit taking it.

He finds out that if he maintains an even dose he avoids all the problems. But he has a limited supply. He originally obtained a bag full with a couple hundred pills (no quantity ever stated), but doesn't know where they come from or how to get more. He hires a chemist to reverse engineer the forumula.

Then his stash is stolen from him, so he's left without any, a 6 month minimum delay before he could possibly see his chemist pay off, and a Russian gangster coming after him.