From: Chris Owen
Subject: ESSAY: Scientology and the Great 10% Myth
Date: 2000-10-03 12:41:32 PST

One of Scientology's favourite promotional leaflets, "endorsed" by Albert Einstein (in image at least), proclaims that the average person uses only 10% of their mental capacity. With Dianetics, this figure can supposedly increase. The same message has been repeated by Scientology for decades. But where does it come from and on what is it based?

Scientology's source for the claim comes from L. Ron Hubbard, as you might expect. In the original "Dianetics: Modern Science of Mental Health", published in 1950, he wrote:

"Thought processes are disturbed not only by these engramic commands but also by the fact that the reactive mind reduces, by regenerating unconsciousness, the actual ability to think. Few people possess, because of this, more than 10% of their potential awareness."

["Dianetics: MSMH", 1988 ed., p. xiii]

This was not a new "discovery" on Hubbard's part. The claim that people only used a small proportion of the brain had been around for many years previously, though just where it came from is unclear. The American psychologist William James declared in 1908 that "We are making use of only a small part of our possible mental and physical resources".

This is probably where Hubbard picked up the idea, as he is known to have read at least some of James' works - James is credited in both "Science of Survival" and "Scientology 8-8008". Strange though it may seem, James was actually Hubbard's favourite psychologist:

"I wouldn't even stoop to kid any one psychologist, except William James. And he actually is quite interesting. They call psychology a science; it would be a science if William James had been able to codify it for communication. Because as far as I can find out, he's the only source for modern psychology. He wrote a book, very nice book. Did you ever see his book - 1898, I think it is, something like that. Very nice little book. If somebody had read that they would have been in good shape, too."

[Hubbard, "Study of the Particle (continued)", lecture of 29 October 1953]

However. the "10% myth" appears to have originated well before James, who was evidently citing "received wisdom". The notion may have its origins in the 19th century pseudoscience of phrenology, which claimed that specific human behaviours and characteristics could be deduced by the pattern and size of bumps on the skull. The 19th century debate was dominated by the question of whether brain functions could be localised to particular regions of the brain or whether the brain acted as a whole. Phrenologists tended to believe in localised brain functions;

the more developed a particular function was, the larger the relevant area of the brain and thus the lumpier the skull in that area. The theory was brought to a grim conclusion in Nazi Germany, where the heads of thousands of Jews, homosexuals and common criminals were carefully examined to record their "defective" characteristics - a practice which had also taken place in "civilised" countries such as Britain and the US.

Phrenology's critics tended to argue that brain functions relied on the brain as a whole and not any specific part. To demonstrate the point, experiments were carried out to carve away the brains of laboratory animals to test how brain functions were progressively impaired. One prominent researcher in this field was Karl Spencer Lashley, whose experiments showed that the ability of rats to solve simple tasks, such as mazes and visual discrimination tests, were unaffected by large-scale removal of cerebral tissue. As long as a certain amount of cortex remained, the rats appeared normal on the tests he administered. In a 1935 experiment, he found that removal of up to 58% of the cerebral cortex did not affect certain types of learning. His results appeared to indicate that large areas of the mammalian brain were effectively unused. "Corroboration" was provided by electrically stimulating exposed cortical tissue in a variety of species. Because this did not provoke an obvious response, it was believed that the bulk of the brain - up to 90% - was "silent" and therefore unused.

But is the claim true? In short, no. Since those experiments were carried out in the 1930s, a wide variety of new techniques have been developed to examine the brain - EEGs, CAT-, PET- and MRI- scans, magnetoencephalography, regional cerebral blood flow measures, etc.

These show conclusively that the so-called "silent cortex" is anything but; rather than dealing with such visible tasks as motor functions, "silent" parts of the brain govern many subtle aspects of thought and personality. Scans show that no part of the brain ever goes "silent";

it may be used at different intensities, but even in the deepest sleep the brain continues to be active. It could hardly be otherwise. The brain consumes a large amount of the body's energy resources, meaning that an efficiently utilised brain is not only desirable but an evolutionary necessity. A mostly unused brain could never have evolved in the first place because of the wasteful overhead it would represent.

Animals, humans included, have brains only as large as they require;

that is why humans don't have whale-sized brains, for instance.

It isn't even clear what is meant by using 10% of the brain. If an individual were to use only 10% of their brain, this means that 90% of each functional area would have to be unused in order not to lose certain functions totally in a 90% dormant brain. It would be much simpler if the brain was an undifferentiated mass, but it isn't. The famous case of Phineas Gage, the 19th century railwayman who was accidentally lobotomised and suffered a radical personality transformation as a result, showed at an early stage that certain areas of the brain have a key role in determining personality. Modern brain scanning techniques show that different areas of the brain are used at different rates of intensity for different tasks. In computing terms, the brain is a cluster of parallel processors rather than one single super-chip.

In conclusion, it's clear that Scientology's claim about only using 10% of the brain is completely incorrect. There is no evidence to support it; the claim itself is based on 19th century pseudoscience and badly flawed early 20th century experimentation. Most ironically of all, the originators of the claim were the very same psychologists whom Scientology professes to hate. This would seem to be an unwitting case of "forwarding the enemy line". It demonstrates - not for the first time - the shallowness and inaccuracy of Hubbard's knowledge about the workings of the brain, and highlights the gulf between his claims and scientific reality.