Sometime during the last few months, either Kenneth Higbee or Samuel
Clay mentioned on TIPS a paper they wrote on the myth that humans use
only 10% of the brain (Higbee & Clay, 1998). At the end of this paper,
they quoted 10 passages from 10 different self-help and other such books
that mentioned some version of the 10% myth. One thing I noticed about
these quotes was that only ONE claimed that we use 10% (or less) of our
brains. The other nine claimed that we use 10% (or less) of some quality
of the brain or mind--qualities such as "brain power", "mental power,"
"brain capacity," "mental potential," and "brain potential." That is,
there really are TWO different kinds of claim with regard to the 10%
myth: (1) normal adults use only 10% (or less) of their brains; and (2)
normal adults use only 10% (or less) of their brain or mind
power/potential/ capacity/energy, or some related concept. From what I
have seen, the second set of claims is more frequently made in the
published literature; and it seems to me to be the older set of claims.

One of the quotes presented in Higbee & Clay (1998) was of particular
interest to me:

"Experts agree that you're using only a fraction of your mental powers.
No less a pundit than Harvard's great psychologist, William James,
claims the average person habitually uses only 10 to 15 percent of his
brain power." (Lewis, 1962, p. 4; quoted on p. 476 of Higbee & Clay,

Did William James start, or at least inspire, what was to become the 10%
myth? No specific reference was given, so I checked his _Principles_ to
see if I could locate anything there, but I found no mention of it. I
started looking through historical works to see what I could find, when
I happened upon Hale (1995). In this book, I found a brief discussion of
James's 1906 presidential address to the American Philosophical
Association (James, 1907a, 1907b) called "The energies of man" (later
called "The powers of man" in a popular article). After reading this
address, it began to seem likely to me that the ideas he expressed in
this address represent the origin of what eventually was to become into
the 10% myth. A couple weeks ago, I spent a few days examining these
ideas and began to write up what I was finding. Since we have talked
about it on TIPS before, I thought some of you might find this to be of
interest. So I present below a very rough sketch of what I have

William James’s Doctrine of Latent Energies

Between 1905 and 1910, there was a strong reaction against the
conventional theory of neurasthenia among some very influential
thinkers. Up to this time, the major cause of neurasthenia was thought
to be overwork. By using a large amount of “nervous energy” for work,
one’s natural allottment was thought to be drained away. Rest was
typically prescribed in order to replenish the depleted store of nervous
energy. In 1906, Robert S. Woodworth criticized this theory and
treatment. In an address he gave to the American Medico-Psychological
Association (the precursor, I believe, of the American Psychiatric
Association), Woodworth stated that “the sacred doctrine that the brain
was liable to fatigue was entirely false” (Hale, 1995; p. 141). Instead,
he argued that there were untapped stores of energy with which we could
work: if we simply worked harder, everything would be fine. In
Woodworth's view, working too little, not working too much, was the root
cause of most of our problems.

In the same year as Woodworth, William James presented a related set of
ideas. In 1906, he claimed that most normal people have vast reserves of
latent “mental energy” that generally are not used in their everyday
activities. James (1907a, 1907b) discussed the mind as being powered by
a sort of “energy”--an idea he attributed to the French psychiatrist
Pierre Janet and to the psychological notion of “dynamogenesis”--a term
then common within psychology that referred to the ability of a stimulus
to cause a bodily movement. The basis for his claim was very simple. It
was the fact that, when we get tired while engaging in a strenuous
activity, if we continue in that activity, we begin to feel more
energetic again. That is, we get our "second winds":

"For many years I have mused on the phenomenon of second wind, trying to
find a physiological theory. It is evident that our organism has
stored-up reserves of energy that are ordinarily not called upon, but
that may be called upon: deeper and deeper strata of combustible or
explosible material, discontinuously arranged, but ready for use by
anyone who probes so deep, and repairing themselves by rest as well as
do the superficial strata." (1907b, p. 57)

In everyday life, we often refer to the “amount of energy available  for
running one’s mental and moral operations” in making sense of daily
fluctuations in our activity (p. 2). By relating this mundane idea to
another one--that of getting one’s "second wind”--James made the notion
of reserves of latent mental energy an intuitively plausible one. His
unique twist on these two related ideas was to suggest that we all have
very large reserves of such latent energy. If circumstances are right,
James argued, and one willed it, this latent energy could be made
manifest by anyone at any time. A further twist was to argue that, if
this was done habitually, a person eventually would run at a new
level--that is, the manifestation of these latent reserves would become

Although James’s idea of latent energy was vague (something he
acknowledged), it did accord with contemporary thinking about the
workings of the nervous system. During the last part of the nineteenth
century and into the first decade of the twentieth century, it was
commonly believed that the nervous system operated through discharges of
nervous energy that tended to move through neural “channels” down which
previous nervous discharges had traveled (see, for example, Swift,
1908). The greater the number of nervous discharges that had previously
traveled through the channel, the easier it became for future discharges
to travel through it. This was thought to be the essence of habit
development. Apparently referring to such ideas, James asserted that his
idea of latent energy “undoubtedly connects itself with the energies of
the nervous system, but it presents fluctuations that cannot easily be
translated into neural terms” (1907a, p. 2). In various ways, James
seemed to be reasoning, the nervous energy making up these discharges
gets "dammed up" or otherwise is inhibited in most people. When this
happens, we have less nervous energy available for powering our actions.
Because of this, James asserted, most of us “are making use of only a
small part of our possible mental and physical resources” (1907a, p. 3).
The idea that the normal person makes use of only a small amount of the
mental energy he/she could be using eventually was referred to as the
“law of latent energy” (Bruce, 1909).

Hale (1995) stated that the law of latent energy (hereafter referred to
as LLE) was part of the “zeitgeist” during the first decade of the
twentieth century. We saw that Robert Woodworth already had been
discussing this idea. Boris Sidis, James’s former student, also
emphasized the importance of this idea, and was credited by Bruce (1909)
as being a codiscoverer of the LLE. In a speech that Sidis made in 1909
at the commencement of the Harvard Summer School, he described briefly
his major assumption:

"It is claimed on good evidence, biological, physiological, and
psychopathological, that man possesses large stores of unused energy
which the ordinary stimuli of life are not only unable to reach, but
even tend to inhibit. Unusual combinations of circumstances,  however,
radical changes of the environment, often unloose the inhibitions
brought about by the habitual narrow range of man’s interest and
surroundings. Such unloosening of inhibition helps to release fresh
supplies of reserve energy." (Sidis, 1917, p. 137)

Sidis was especially interested in transforming our views of childhood
education to take advantage of these reserves of energy:

"The child is essentially a thinking animal. No power on earth can keep
him from thinking, from using his mind. From the moment his inquiring
eyes first take in the details of his surroundings he begins the mental
processes which education is intended to guide and develop.... Left to
himself, however, he is certain to observe inaccurately and to make many
erroneous inferences. Unless he is taught to think he is sure to think
incorrectly, and to acquire wrong thought habits.... In fact, in order
to get the best results, his training in the principles of correct
thinking should begin as soon as, or even before, he starts to talk.
There need be no fear of over-taxing his mind. On the contrary, the
effect will be to develop and strengthen it, by accustoming him to make
habitual use of the latent energy which most people never utilize at
all."" (quoted in Bruce, 1909, p. 692; emphasis added)

The LLE as described by Sidis and James struck a chord with many
influential Americans: “Indeed, Sidis and James’s doctrine of ‘vital
reserves’ became a widespread and exhilirating conviction, common to New
Thought, the Emmanuel Movement, and some medical psychotherapists”
(Hale, 1195, p. 244). As an example of the excitement generated by the
LLE among the “mind-curers” and others, we can look at a statement made
by H. Addington Bruce (1909), apparently a friend of Boris Sidis and a
proponent of mind-cure (see Bruce, 1910):

"Two years ago Prof. William James, in one of the most remarkable
articles ever published in this or any other periodical,
formulated...his startling psychological doctrine of the hidden energies
of man.... The controversy which these views of Professor James provoked
still waxes warm. For the most part his scientific colleagues are at
odds with him. Yet all the time, while his critics have been criticizing
him, facts have been coming to light tending to prove that Professor
James’s theory, far from being a gospel of overstrain, is a gospel of
hope, opening up to the human race vistas of possibilities and
achievement unreached in any epoch of the history of the world." (p.

There seems to be little doubt that James’s ideas about vast reserves of
human energy and power had a large influence at this time. But was this
the influence leading to the present-day 10% myth? There is evidence
that the answer to this question may be “yes.” In fact, at least into
the 1960’s, self-help manuals continued to refer to James when
discussing unused mental “powers” and “potentials,” as you saw with the
quote from Lewis (1962) that started my research on this. The director
of the “Human Potentialities Research Project” at the University of
Utah, Herbert Otto (1966) also mentioned James: “In the past two
decades, an increasing number of behavioral scientists have concluded
that man is functioning at 10% or less of his potential. This
observation is by no means new, having been formulated by William James
at the turn of the century” (p. 3). Neither Otto nor Lewis gave a source
for this claim, and I have been able to find no article in which James
presented an exact percentage of average mental powers used by normal

It seems very unlikely that James ever suggested a precise percentage of
total mental energy typically used in everyday life because he seemed to
feel that such a measurement would have had little meaning. He believed
that, although mental energy “offers itself as the notion of a quantity,
...its ebbs and floods produce extraordinary qualitative results”
(1907a, p. 2); and, “in measuring the human energies of which I speak,
qualities as well as quantities have to be taken into account” (1907b,
p. 58). It seems that the closest James ever got to specifying a
proportion was when he claimed that we “are making use of only a small
part of our possible mental and physical resources” (1907a, p. 3). James
stated this belief more clearly in an article meant for a popular
audience: “The first point to agree upon in this enterprise is that as a
rule men habitually use only a small part of the powers which they
actually possess and which they might use under appropriate conditions
(1907b, p. 59; emphasis in original). I do not yet have proof, but I
believe that others, probably in one of the popular periodicals of the
day, perverted this statement by assigning a particular percentage to
the amount of mental energy we normally use.

Using One’s Latent Energy

How was one to use these latent stores of energy? Or, to use the word
that James, Sidis, and others preferred, how could one learn to
“energize”? And what exactly could one expect when one did energize
habitually? James (1907b) stated that people who energize to a high
degree tend to have one or both of the following experiences: “Either
some unusual stimulus fills them with emotional excitement, or some
unusual idea of necessity induces them to make an extra effort of will.
Excitements, ideas, and efforts, in a word, are what carry us over the
dam” (p. 59). Sidis, who recommended intensive educational experiences
beginning during the first year of life, was somewhat more specific.
According to Bruce (1909):

"Dr. Sidis has, in the main, relied on the familiar educational
principle of teaching a child through appealing to his interest, but he
has made the appeal to interest in an unusual way--namely, by systematic
application of the influence of that little understood but tremendously
powerful psychological factor, “suggestion.” ... Dr. Sidis believed
that, if properly manipulated, the method of education through play
might be extended to subjects not taught in the kindergarten--that in
fact, a child might be led [by suggestion] to undertake and continue the
study of any subject provided it were made sufficiently interesting to
him." (p. 693)

In fact, he raised his own child, William James Sidis (the namesake of
his former mentor), using these methods. If one wanted to see for
oneself what the effects of training for a high degree of energizing
could do, the accomplishments of young William James Sidis was the place
to look. Boris Sidis constantly monitored his son's educational
experiences throughout childhood and arranged matters so that William
would learn to use most of his latent energy habitually. For example,
when Boris found that William did not like mathematics, he used
suggestion in the following way:

"Dr. Sidis did not attempt to drive him to the study of mathematics.
Instead, he purchased some toys--dominoes, marbles, etc.--with which he
invented games requiring more or less knowledge of addition,
subtraction, multiplication, and division. Every evening, for an hour or
more, he played these games with his little son, deftly managing matters
so that his interest in time shifted from the toys to the principles
underlying their use. In the boy’s presence, too, he continually
discussed with Mrs. Sidis...questions involving the practical
application of arithmetic and “suggesting” its importance in the affairs
of every-day life." (Bruce, 1909, p. 694)

And what effect did this have on the younger Sidis? “This process proved
so effectual that the boy spontaneously, and with the greatest
enthusiasm, took up the study of mathematics, progressing in it so
rapidly that in a couple of years his mathematical knowledge was
superior to that of his father” (p. 694).

According to Bruce (1909), Wiliam progressed through all his studies
very rapidly. He learned to read and write by three years of age. At the
age of six, he allegedly completed the first seven grades of school in
half a year. He was schooled at home for two years and then allegedly
completed high school in three months. After another two years of home
schooling, he entered Harvard at age eleven to study mathematics and
other subjects. Nevertheless, the article makes clear that William was
“no bulging-browed, bespectacled, anaemic freak” (p. 691). No, he was a
boy just like any other: “His cheeks have a ruddy glow, his eyes
sparkle, he has a ringing laugh, and is fairly bubbling over with animal
spirits” (p. 691). What then, if not superior native ability, was the
source of young William’s preeminence in academic matters? His father’s
techniques for “energizing,” of course. The message of the article was
that anyone could repeat young William's feats if one learned to
energize properly.

In order to reinforce this message, several other anecdotes were given
by Bruce (1909), including one of a “rather stupid and quite uneducated”
tailor, forty years of age, who wanted to be of service to humanity and
who came to Sidis for help. Sidis proceeded to educate and energize the

"He came to me every day, and when he was not with me he was studying
the text-books I gave him to read. I kept him at work, with his mind set
on the distinct goal of helping his fellow man.
"Before long, he displayed an intellectual ability that amazed those who
had known him  before the process of energizing began. He seemed, as
some of his friends said to me, to be a new man. Whereas before he had
been timid and diffident he became self-assertive and masterful. He
attended and even organized workingmen’s clubs, he developed a marked
gift as a public speaker, and before his death...won considerable
reputation as a labor leader." (p. 695)

The moral of this anecdote is obvious: if such a stupid and educated man
at the beginning of middle age could be “energized” to accomplish such
feats, imagine what it could do for you! From what I can tell, the
notion of latent reserves of mental energy spread like wildfire because
of its very optimistic message. The imprimatur of the renowned William
James was the spark that ignited the fuel spread by movements such as
New Thought and "mind cure."


I predict that, if we search for the sequelae of James's and Sidis's
claims into the 1910's and 1920's (most likely in periodicals meant for
lay audiences), we will find that they inspired the 10% myth. In fact,
just yesterday (I wrote the above two weeks ago), I received a copy of a
book in which Barry  Beyerstein (1999) also suggested that William
James's presidential address was an influence on the development of
the10% myth (I saw that TIPSie Bob Keefer was acknowledged in this
chapter). Since Beyerstein has been investigating the sources of this
myth for quite a while, I am even more confident that James is the main
inspiration for the 10% myth, along with the anecdotal evidence for LLE
reported by his former student Boris Sidis.

Any thoughts on this? In a second post, I am going to discuss a possible
neurological justification for the claim that humans have vast reserves
of brain/mental capacity that go unused, an idea that, when put together
with James's thoughts about LLE, may go a long way towards explaining
the origins of the 10% myth.

As always, sorry about the length,



Beyerstein, B. (1999). Whence cometh the myth that we use only ten
percent of our brains? In S. Della Sala (ed.), Mind myths: Exploring
popular assumptions about the mind and brain  (pp. 3-24). New York: John
Wiley & Sons.

Bruce, H. Addington. (1909). Bending the twig: The education of the
eleven year old boy who  lectured before the Harvard professors on the
fourth dimension. The American Magazine,  69, 690-695.

Bruce, H. Addington. (1910). The new mind cure based on science:
Including stories of  wonderful cases where relief has been supplied
without the aid of surgery or medicine. The  American Magazine, 70,

Hale, N. G. (1995). Freud and the Americans: The beginnings of
psychoanalysis in the United States, 1876-1917  (Vol. 1). New York:
Oxford University Press.

Higbee, K. L., & Clay, S. L. (1998). College students’ beliefs in the
ten-percent myth. The Journal of Psychology, 132, 469-476.

James, W. (1907a). The energies of men. Philosophical Review, 16, 1-20.

James, W. (1907b). The powers of men. American Magazine, 65, 56-65.

Sidis, B. (1917). Philistine and genius. New York: Moffat, Yard & Co.

Swift, E. J. (1908). Mind in the making: A study in mental development.
New York: Charles Scribner’s Sons.

Jeffry P. Ricker, Ph.D.          Office Phone:  (602) 423-6213
9000 E. Chaparral Rd.            FAX Number: (602) 423-6298
Psychology Department            [EMAIL PROTECTED]
Scottsdale Community College
Scottsdale, AZ  85250

"For every problem, there is a solution that is neat, simple, and
wrong."          H. L. Mencken

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