About Rationally Speaking


Rationally Speaking is a blog maintained by Prof. Massimo Pigliucci, a philosopher at the City University of New York. The blog reflects the Enlightenment figure Marquis de Condorcet's idea of what a public intellectual (yes, we know, that's such a bad word) ought to be: someone who devotes himself to "the tracking down of prejudices in the hiding places where priests, the schools, the government, and all long-established institutions had gathered and protected them." You're welcome. Please notice that the contents of this blog can be reprinted under the standard Creative Commons license.

Monday, June 04, 2007

Not true: you don't use only 10% of your brain

This idiotic statement has become a widespread urban myth, the origin of which is difficult to track, according to an article by Benjamin Radford in snopes.com (a highly recommended website for urban legends and assorted crap that people believe without evidence).

As Radford points out, that it is a myth is obvious as soon as one actually engages her (full) brain for more than a moment to ponder the claim itself: if we really used only a fraction of our thinking organ, why do brain scans show large areas of it being activated by a variety of different tasks? Moreover, why is it that brain injuries so often carry awful alterations of the victim's thinking abilities, and even personality? If 90% of the stuff is useless, then brain surgeons could afford to be much less careful with the object of their operations, no?

Radford reports that there are several versions of the myth, all of which don't stand up to even a superficial scrutiny. For example, some people claim that the unused 90% is part of the subconscious, but the subconscious does a lot of work, and in fact is crucial in providing us with the pre-processed thinking material that eventually emerges to the level of consciousness and is the basis on which we make our decisions (also known as “intuition”). A more charitable interpretation of the myth is that we use only a percentage of the brain at any given time (though the 10% figure still comes out of thin air). That is definitely true, but trivially so: in the same way, we don't use all of our muscles at the same time, but that doesn't mean that a large part of our muscular system is therefore useless, or is waiting to be tapped into to make us superhuman.

The latter is apparently the main reason the myth persists. According to Radford, psychics and other cuckoos use the allegedly missing 90% as an “explanation” of why some people develop psychic powers. Uri Geller, the notorious buffoon who claims to be able to bend metal by sheer mental power, for example, has written that “our minds are capable of remarkable, incredible feats, yet we don't use them to their full capacity. In fact, most of us use about 10 percent of our brains, if that” (from Uri Geller's Mind-Power Book, cited by Radford). Well, maybe people who buy Geller's books use a fraction of their brains, but of course the claim is a non sequitur even if the 10% myth were in fact true: Geller, like many other psychics, paranormalists, ufologists and creationists, is making an argument from ignorance (often, as in this case, their personal one). He is saying that since we don't know what the missing part of the brain does, then it must be involved in psychic powers; but for all we know the true function of the 90% of the brain that we allegedly don't use could have been set aside to store the details of all the soap operas that we care to watch. Wouldn't that be clear evidence of intelligent design (and of God's endorsement of daytime TV)?

The fact of the matter is that we actually use all areas of our brain, at different times and for different purposes. The real mystery is how is it possible that people endowed with roughly the same amount of matter capable of generating reasoning can come to dramatically different understandings of the world, with such a large percentage (about half of the United States population, if one uses creationism as a reference) so completely off the mark set by reality.

15 comments:

  1. Great post! I remember how sceptical I was when heard this claim for the first time, it just does not make any sense.

    Later on I have tried to think of explanation. One explanation of this myth could also be that only a fraction of our brain actually consists of neurons. The great majority (I cannot remember if it is 90% or 99%) is glia matter.

    But to say that we don't "use" glia matter is of course a very silly thing to say. Just look at people who get MS, they would sure like that useless stuff back in their brain...

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  2. M: The real mystery is how is it possible that people endowed with roughly the same amount of matter capable of generating reasoning can come to dramatically different understandings of the world, with such a large percentage (about half of the United States population, if one uses creationism as a reference) so completely off the mark set by reality."

    Yeah, that's a hard one.

    We make most of our decisions in reference to perception based on what we think doing or trying a particular thing might cost us.
    And costs could mean just basic stuff like friendships, sex, happiness etc. Usually not anything much deeper than that.

    And I mean, hey, what's not equally as "deep" as pondering the purchase of some Tiramisu Gelato?

    For months I had looked it over with curiosity at Trader Joes & I didn't much like the sound of the combination at all. Now I like Tiramisu. And almost as much, I also like Gelato. But the thing that hung me up for a rather long time is that tho I thought the two were so good separately it would be extremely disappointing to try them as like "one food".

    Similarly, our preconceptions about what we think will make life work well often keep us from a lot of really great things. And I am absolutely certain that many people short-change themselves emotionally and spiritually in life this way.

    well, if the truth must be known, I did buy the Tiramisu Gelato last week and it is like the BEST thing in the world!! ;) YUM!!!!

    So what if in the end it turns out that our fear and our lack of understanding of what some particular idea really is, totally keeps us from being able to try out what that thing REALLY IS?

    that could actually happen

    cal

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  3. Cal

    Seeking to rival Hazlitt in the informal essay, are we?

    *

    "So what if in the end it turns out that our fear and our lack of understanding of what some particular idea really is, totally keeps us from being able to try out what that thing REALLY IS?"

    Does not that door swing both ways?

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  4. Paul: "Does not that door swing both ways?"

    Absolutely.

    But I was more or less born a secular humanist. Plus there was an individual in my growing up years who rather influenced me to really take that philo. on and run with it. So, been there, done that, drove a good portion of the good people in my family (almost) to insanity.
    So now, as to never underestimate the power of our influence in other people's lives,(and because someone certainly was able to place their spell on me for a time) I designate some time and energy to "encourage" several of my nephews and a few others who lean to the left from taking the identical route.



    yes, sir. the door definitely swings both ways...but the chances that I'll run back through it again in the "other" direction are about zero to none. ;)

    best regards...
    cal

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  5. Aureola Nominee, FCDJune 05, 2007 1:05 PM

    Ah, yes, "I was a secular humanist once, you know."

    And yet, on every occasion when cal has tried to claim any knowledge of what evolution is and evolutionists claim, or what atheism is and what atheists claim, or more in general how the "other side" actually thinks and says, she's displayed either abysmal ignorance or willful misrepresentation.

    Let me spell it out clearly, cal: I DON'T BELIEVE YOU. You have given us repeated demonstrations of not knowing how a "secular humanist" thinks.

    (It's also a very unoriginal Creationist rhetorical trick, but we all know that you love using them regardless of how old and tired they may be.)

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  6. IT'S NOT TOO HARD TO FULLY UNDERSTAND HOW CAL MIGHT VERY WELL DRIVE HER RELATIVES TO INSANITY. sHE WOULD DRIVE ALL OF US MAD TOO IF WE CONSIDERED HER BLATHERINGS ANYTHING MORE THAN PROOF OF THE WRONGNESS OF THE FLIP SIDE OF REALITY.RJPMC

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  7. "encourage" several of my nephews and a few others who lean to the left from taking the identical route

    And who said only those who "lean to the left" can be secular humanists???

    I myself know three members of the Republican party here in VA who are openly and active atheists!

    Oh, well. That's what a simplistic world view will do to you.

    J

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  8. "And yet, on every occasion when cal has tried to claim any knowledge of what evolution is and evolutionists claim, or what atheism is and what atheists claim, or more in general how the "other side" actually thinks and says, she's displayed either abysmal ignorance or willful misrepresentation."

    Reminds me of C.S. Lewis who "converted" from atheism to Christianity. If I had the impression of atheism and materialism that he demonstrated in his writing, I would probably be a christian too. Fortunately, it's a straw man and someone as "learned" as Lewis should have known it.

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  9. Aureola Nominee, FCD said...

    Ah, yes, "I was a secular humanist once, you know."

    And yet, on every occasion when cal has tried to claim any knowledge of what evolution is she's displayed either abysmal ignorance or willful misrepresentation.
    "

    I did not think of myself as a secular humanist either, fcd. I just wanted to separate myself from everything Christian. Whatever that may imply. I was in my mid-late teens when someone first showed me a humanist manifesto. And even tho I understood that what I was looking at was not really what I was wanting to become, it took many years for me to leave the vestiges of the way I thought about myself and my responsibilities to my family and their beliefs behind.

    for myself, I think that some people can be very humanistic without being a card carrying member of a humanist org. But you are a skeptic. So I guess I expect you to think like one.
    cal

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  10. "IT'S NOT TOO HARD TO FULLY UNDERSTAND HOW CAL MIGHT VERY WELL DRIVE HER RELATIVES TO INSANITY."

    You are absolutely correct, Dennis. If I begin with some project that I am certain should be resolvable, I don't let go until it is resolved. And that could be never or forever.

    But that doesn't matter. People matter. & people are the only things in this world that are "forever".

    cal

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  11. c: "If I had the impression of atheism and materialism that he demonstrated in his writing, I would probably be a christian too. Fortunately, it's a straw man and someone as "learned" as Lewis should have known it."

    Back to perception and preconception. Learned people can "learn" that they are not capable of doing somethings for themselves. And knowing what one is able to do and what one has to ask someone else to do for you, is the MOST INTELLIGENT thing one can possibly opt for. It is plainly foolish pride that says, I can do everything in this life (and outside of it) for myself.

    That would not be a particularly learned man in my estimation.

    stuff to do, places to go..
    have a good day, you guys

    cal

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  12. Aureola Nominee, FCDJune 06, 2007 11:30 AM

    cal:

    Where in the world did I refer to "humanistic organizations" or "card-carrying members"? This looks like another strawman to me.

    Rejecting Christianity, for a teen-ager brought up within Christianity, is often simply an expression of (a phase of) rebellion, and your description seems to fit this idea to a t.

    What makes someone a humanist is having certain attitudes and opinions about the world, NOT simply rebelling against one's parents' "received wisdom". Do not confuse the two concepts, because they are very different.

    Many of those supposed "rebels" outgrow their rebelliousness and return to the fold... because in practice they never left the fold, never thought hard about what was wrong (or right!) in the temporary target of their angst.

    What people should do is examining critically every idea that they are presented with, no matter how "sacred" or "traditional" or "authoritative" it may be, studying it and finding out whether it is supported by the available evidence. The world is full of shades of gray. A lot of people find this confusing and difficult, and seek solace in simplistic, black-and-white worldviews. Fundamentalist Christianity is the escapist fantasy of choice in the USA; other cultures have other forms of reality-denial.

    Finally, this mechanism is by no means limited to the Religious Right; woo-meisters like Deepak Chopra are promoting spiritual nonsense every bit as delusional - if a little less hate-filled - as any Jerry Falwell or Fred Phelps.

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  13. Massimo,

    I'm not sure that your premise concerning brain usage is correct. I've been reading "cal's" posts and they seem to make the most sense when 2% or less of the brain is used.

    Lurker

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  14. Not regarding the cal problem for a minute...great post! And snopes.com is truly and excellent and informative website. The research they do is amazing, and the simple premise of researching and questioning everything that one hears and takes for granted has, to use the overused phrase, changed my life.

    No, you don't use only 10% of your brain, and it DOESN'T take fewer muscles to smile than to frown! And shaved hair doesn't grow back thicker...now if I can just get my mother a computer so she can get the facts on these old wives tales. What people tell their kids, I swear...;-)

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  15. The myth is silly..... but I have heard (perhaps this is a new myth?) that neuroscience now believes that after 50 or so years of research they have a good grasp on about 10% of how the brain works (chemically, electrically, physiologically, anatomically etc). That I buy, except for how one can estimate what they don't know.....

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