IQ Test Labs Monthly
Newsletter - Subscribers only
Puzzles and Teasers
2. Article: Do we use only 10% of our
3. Quotes and trivia
4. Site of the week
5. Book Review: Match Wits with Mensa
6. Word of the month
7. Latest news and developments
Puzzles and Teasers
Mathematical Brain Teaser
You begin reading a book 240 pages long. If you read half
of the remaining book each day how long would it take you to
finish the book?
Logic Brain Teaser
You are at a game show and there are three closed doors.
There is a prize hidden behind one of the doors and the game
show host knows where it is. You are asked to choose a door.
The game show host then opens one of the other two doors
showing that it is empty and asks you if you would like to
change your selection. Should you stick to your original
Lateral Brain Teaser
There is a barrel with no lid and some beer in it. "This
barrel is more than half full," said Chuck. "No it's not," say
Joe. "It's less than half full." Without any measuring
implements and without removing any beer from the barrel, how
can they easily determine who is correct?
Word Play Puzzles
The letters represent words that are somehow connected in a
You must identify the next letter in the sequence.
Clue: M T W T ?
Explanation: ..... Wednesday (W), Thursday (T),
Question: T T T F F S S ?
Different words are used to describe well known proverbs
Puzzle: "Rap upon timber"
Solution: "Knock on wood."
Question: Members of an avian species of identical plumage
Each equation contains the initials of words that will make
the statement true. The statements are well-known facts from
the everyday world. Identify the missing words that will make
each statement true.
Equation: 1001 = A. N.
Solution: 1001 Arabian Nights
Question: 24 = H. in a D.
The following words are used in different orientations to
represent common phrases.
FLIGHTFLIGHT can be interpreted as 'Connecting Flights'
Question: .That is
What do these words have in common: age, blame, curb,
dance, evidence, fence, gleam, harm, interest, jam, kiss,
latch, motion, nest, order, part, quiz, rest, signal, trust,
use, view, win, x-ray, yield, zone?
What has no content yet you can see it?
Tests and games (Links to other sites)
Are you an efficient reader? What kind of reader are you? You
will know in a few minutes after you have completed this free
online speed reading test.
Do we only use 10% of our brains?
by Dr. Eric H. Chudler
Do we use only 10% of our brains?
The question is: Do we use only 10% of our brains?
Dr. Eric H. Chudler
Let me state this very clearly:
There is no scientific evidence to suggest that we use only 10% of
In other words, the statement, "We use only 10% of our brains" is
false; it's a myth. We use all of our brain. Let's look at the
possible origins of this myth and the evidence that we use all of
Where Did the 10% Myth Begin?
The 10% statement may have been started with a misquote of Albert
Einstein or the misinterpretation of the work of Pierre Flourens in
the 1800s. It may have been William James who wrote in 1908: "We are
making use of only a small part of our possible mental and physical
resources" (from The Energies of Men, p. 12). Perhaps it was the
work of Karl Lashley in the 1920s and 1930s that started it. Lashley
removed large areas of the cerebral cortex in rats and found that
these animals could still relearn specific tasks. We now know that
destruction of even small areas of the human brain can have
devastating effects on behavior. That is one reason why
neurosurgeons must carefully map the brain before removing brain
tissue during operations for epilepsy or brain tumors: they want to
make sure that essential areas of the brain are not damaged.
Why Does the Myth Continue?
Somehow, somewhere, someone started this myth and the popular media
keep on repeating this false statement. For example one
advertisement for an airline states: "It's been said that we use
a mere 10% of our brain capacity. If, however, you're flying ****
from **** Airlines, you're using considerably more." Soon,
everyone believes the statement regardless of the evidence. I have
not been able to track down the exact source of this myth, and I
have never seen any scientific data to support it. According to the
believers of this myth, if we used more of our brain, then we could
perform super memory feats and have other fantastic mental abilities
- maybe we could even move objects with a single thought. Again, I
do not know of any data that would support any of this.
What Does it Mean to Use Only 10% of Your Brain?
What data were used to come up with the number - 10%? Does this mean
that you would be just fine if 90% of your brain was removed? If the
average human brain weighs 1,400 grams (about 3 lb) and 90% of it
was removed, that would leave 140 grams (about 0.3 lb) of brain
tissue. That's about the size of a sheep's brain. It is well known
that damage to a relatively small area of the brain, such as that
caused by a stroke, may cause devastating disabilities. Certain
neurological disorders, such as Parkinson's Disease, also affect
only specific areas of the brain. The damage caused by these
conditions is far less than damage to 90% of the brain.
The Action Potential The Evidence (or lack of it)
Perhaps when people use the 10% brain statement, they mean that only
one out of every ten nerve cells is essential or used at any one
time? How would such a measurement be made? Even if neurons are not
firing action potentials, they may still be receiving signals from
other neurons. Furthermore, from an evolutionary point of view, it
is unlikely that larger brains would have developed if there was not
an advantage. Certainly there are several pathways that serve
similar functions. For example, there are several central pathways
that are used for vision. This concept is called "redundancy" and is
found throughout the nervous system. Multiple pathways for the same
function may be a type of safety mechanism should one of the
pathways fail. Still, functional brain imaging studies show that all
parts of the brain function. Even during sleep, the brain is active.
The brain is still being "used," it is just in a different active
state. Finally, the saying "Use it or Lose It" seems to apply to the
nervous system. During development many new synapses are formed. In
fact, some synapses are eliminated later on in development. This
period of synaptic development and elimination goes on to "fine
tune" the wiring of the nervous system. Many studies have shown that
if the input to a particular neural system is eliminated, then
neurons in this system will not function properly. This has been
shown quite dramatically in the visual system: complete loss of
vision will occur if visual information is prevented from
stimulating the eyes (and brain) early in development. It seems
reasonable to suggest that if 90% of the brain was not used, then
many neural pathways would degenerate. However, this does not seem
to be the case. On the other hand, the brains of young children are
quite adaptable. The function of a damaged brain area in a young
brain can be taken over by remaining brain tissue. There are
incredible examples of such recovery in young children who have had
large portions of their brains removed to control seizures. Such
miraculous recovery after extensive brain surgery is very unusual in
So next time you hear someone say that they only use 10% of their
brain, you can set them straight. Tell them,
"NOT TRUE; We use 100% of our brains."
If you find any news articles or advertisements
using the 10% myth, please send them to: Dr. Eric H. Chudler; Dept.
Anesthesiology, BOX 356540; University of Washington; Seattle, WA
For a continuing discussion of this topic, please see:
Ten Percent and Counting - BrainConnection.com
The Ten-Percent Myth from the Skeptical Inquirer
The Ten-Percent Myth
Higbee, K.L. and Clay, S.L.,
College students' beliefs in the ten-percent myth, Journal
of Psychology, 132:469-476, 1998. B.L. Beyerstein,
Whence Cometh the Myth that We Only Use 10% of Our Brains? in
Mind Myths. Exploring Popular Assumptions about the Mind
and Brain edited by S. Della Sala, Chichester: John Wiley
& Sons, pages 3-24, 1999.
Did you know?
Dr. James W. Kalat, author of the
textbook Biological Psychology, has another idea for the
origin of the 10% myth. Dr. Kalat points out that
neuroscientists in the 1930s knew about the existence of the
large number of "local" neurons in the brain, but the only
thing they knew about these cells is that they were small. The
misunderstanding of the function of local neurons may have led
to the 10% myth. (Reference: Kalat, J.W., Biological
Psychology, sixth edition, Pacific Grove: Brooks/Cole
Publishing Co., 1998, p. 43.)
They said it!
"Myths which are believed in tend
to become true..."
--- George Orwell (in The Collected Essays, Journalism, and
Letters of George Orwell, vol. 3, edited by Sonia Orwell and
Ian Angus, New York: Harcourt Brace Jovanovich, 1968, page 6.)
"In fact, most of us use only
about 10 percent of our brains, if that."
--- Uri Geller (in Uri Geller's Mindpower Kit, New York:
Penguin Books, 1996.)
Quotes and Trivia
A jellyfish has no brain.
Studies show that IQ is modestly related to the
speed at which you do some pretty simple things such as comparing
two lines to see which is longer.
Think like a wise man but communicate in the
language of the people.
--William Butler Yeats
Great spirits have always found violent opposition
from mediocrities. The latter cannot understand it when a man does
not thoughtlessly submit to hereditary prejudices but honestly and
courageously uses his intelligence.
-- Albert Einstein
Site of the week
60 Optical Illusions & Visual Phenomena
demonstrate visual phenomena, called »optical illusions« or
»visual illusions«. The latter is more appropriate, because most
effects have their basis in the visual pathway, not in the optics
of the eye...
Match Wits with Mensa
Match wits with the 70,000 certified geniuses of Mensa, the
high-IQ society! Here are more than 800 fun mindbenders to
exercise every part of your brain - word games, trivia, logic
riddles, number challenges, visual puzzles-plus tips on how to
improve your thinking skills. All the puzzles have been tested
by members of American Mensa, Ltd., and include the percentage
of Mensa testers who could solve each one, so that you can score
yourself against some of the nation's fittest mental athletes.
List price is $22.50. You can save 32% by ordering from
Amazon.com for $15.30
Word of the month
ailurophile (eye-LOOR--uh-fyle, ay-LOOR-) noun One
who loves cats. [Greek ailouros, cat + -phile.]
Word in context: "It's said in publishing that no
cat book ever loses money. Maybe it's true: bibliophiles tend to
be ailurophiles, and both are tenacious breeds." Toth, Emily, Meow
mix, Women's Review of Books, 1 Jul 1995.
Latest news and developments
Researchers see steady rise in IQ test scores
'PQ' provides a video game test of your IQ
Autism surrounded by misunderstanding - experts
Orphaned boys and girls react differently to care
Back to newsletter index