This is perhaps the most persistent and widespread belief about the brain. Like a
Dawkinian meme it has infiltrated deep
into the collective psyche, permeating society and influencing popular
cultural. Entire novels, plays and movies are built on this motif and, being so
pervasive, some movies don’t even need to explain the idea. For instance in the
movie “Defending your Life” Albert
Miller dies in a car accident and upon reaching the afterlife finds he has to
justify his fear-based life or be “sent back”. It is explained to Miller that, due to fear,
humans use so little of their brain potential with his defence attorney asserting,
"When you use more than 5% of your
brain, you don't want to be on Earth, believe me." Similarly, in the
movie “Wedding Crashers” an oblique
reference is made to the 10% belief when one of the characters asserts that men
only use 10% of their hearts. But the latest (and in my opinion the best) movie
portrayal of this belief is to be found in the 2011 film “Limitless” in which Eddie, a struggling writer, is persuaded by
his ex- wife’s brother, Vernon, to try a new drug, NZT-48, that will allow him
to access 100% of his brain:
Eddie:
“What’s in it?”
Vernon: “They’ve
identified these receptors in the brain that activate specific circuits. And
you know how they say we can only access 20% of our brain…Well what this
does…it let’s you access ALL of it.”
This belief is commonly used as a motivator
for unleashing untapped potential; for instance, it has been claimed that
Einstein used 15% of his brain and
that if only we could employ an equal percentage of our brain capacity we too could be “Einsteins”. It is also used by some (Uri Geller) as an
explanation for paranormal phenomena; the idea being that during our
prehistoric past, as we hunted and foraged amidst the vast and hostile
environment of the African savannah, ESP abilities served a survival utility;
but that due to the “civilising” effect of modern society, with the associated
reliance on technology, these once adaptive ESP abilities have atrophied among
the general populace.
But just where did
this idea come from? And more importantly, is it true? If we look back through
the history of neuroscience and psychology one place where we find a hint of
this idea is in the writings of William James (1842-1910). In popular public
lectures William James often claimed that we only reach a small fraction of our
brain’s full potential. More
specifically, James came up with the idea of reserve energy which supposes that within the individual there are
both physical and mental reserves of energy which can be tapped into and
utilised. This idea is presented in his 1907 article “The Energies of Men”. American psychologist and James’s protégé,
Boris Sidis, used this idea as the basis of an educational experiment with his
son William Sidis. Boris commented on
his application of reserve energy in the raising of his son in a circa 1910
issue of New York
American:
“I do
not believe in the prevailing system of education for children. I have raised my
son upon a system of my own, based to some extent upon the principles laid down
by professor William James.”
Judging form the results of this experiment
(it is claimed William Sidi had an IQ of 250 – 300!) there would appear to be
some truth to James’ reserve energy theory. Such results highlight that the
critical period of neuro-genesis, synapto-genesis and pruning that takes place
during early childhood is very much shaped by expectations and experience. If
the case of William Sidi is to be taken at face value it strongly suggests that
he was utilising the potential of the human brain in a manner not typical of
conventional childhood development.
But, the origins of the 10% idea originate
with James only indirectly. It is through the writings of self-help guru Dale
Carnegie (1888 – 1955), and specifically his “How to Win Friends and Influence People” that this idea gained
traction. The idea that we only use 10%
of our brain was first mentioned by Robert Lovell in the introduction to the
1936 edition of the book quoting William James as saying:
“Compared
to what we ought to be we are only half awake. We are making use of only a
small part of our physical and mental resources. Stating the thing broadly, the
human individual thus lives far within his limits. He possesses powers of
various sorts which he habitually fails to use.”
Of course, James’s argument that we are not making
full use of our potential is inarguable;
just as we don’t make full use of the potential of our bodies physical
capacities we similarly don’t make full use of the brains full potential. But
the 10% myth isn’t usually framed in such terms; rather, it asserts that the
fully developed adult brain is underutilised in so far as only a small
percentage of the brain’s function is
being utilised. This conjures up the
image of only a small region of the brain being active while the remaining 90%
lays dormant. The myth couched in these
terms is easy to dismiss. Lesion
evidence (seeing what goes wrong when certain parts of the brain are damaged)
and modern imaging techniques (fMRI, PET) thoroughly demonstrate that every part of the brain is necessary for
normal function. However, if the question is framed in terms of how much of
that normal brain function is under conscious
control, a less clear cut and more interesting avenue of thought opens up.
In his book “Brain Wars” neuroscientist Mario Beauregard relates the well
documented case of a man named John who suffered from a debilitating disease
known as ichthyosiform erythrodermia
or “fish skin” in which his whole body was covered in a thick black substance
bearing no resemblance to healthy, normal skin. After trying numerous unsuccessful
skin grafts, and out of sheer desperation, it was suggested by anaesthiologist
Albert Mason, who’d had some reasonable success with warts, to try
hypnotherapy. Mason treated John’s right arm, moving onto the trunk and the
legs, giving him basic hypnotic suggestions such as “Your right arm will
clear”. This initial hypnotherapy
resulted in 50% of his legs and 95% of his right arm clearing; within a year of
completing treatment John had become a “normal, happy young man”.
Such cases as John’s above, as well as such
inexplicable phenomena as the placebo effect, strongly suggest that, at the
very least, there are potentials for self-healing that ordinarily we are
unaware of. These potentials for healing are usually not amenable to conscious
manipulation but somehow, in a way not fully understood, certain mind states
increase one’s ability to utilise potentials for healing not typically under
our control. Hypnosis is just one way of accessing this generally unconscious
potential. Similarly, there are documented accounts of advanced yoga
practitioners controlling physiological responses not usually open to to
conscious control.
So, while the 10% myth, as popularly thought
of, is easily debunked in light of the overwhelming evidence to the contrary, I
think it would be arrogant to suppose that out knowledge of the brain and its
potential is complete. Neuroscience is a relatively young science and I believe
many surprises still await us.