Surely you have heard the famous phrase that we only use 10% of our brain. In fact, a third of my Psychobiology students believe it, and another large percentage “does not know, does not answer”. It is one of the most widespread hoaxes in the field of neuropsychology. And when we came across it, we thought, “What if we used 100%? Would we then be like Einstein?
The plot of the movie Lucy (2014), starring Scarlett Johansson and Morgan Freeman, is based on precisely this idea: if the remaining 90% of our capacity could somehow be harnessed, superhuman powers would be unlocked. I do not continue not to do spoilers.
In this article, I intend to debunk this neuromyth and reassure you: we use all of our brains, but obviously not all of them at the same time.
Because, effectively, we use 100% of an organ that represents only 2% of the body weight and that requires 20% of the energy consumed. It would be something like saying that someone uses only 10% of their leg muscles to run. Use absolutely all of them, although not to their full capacity.
a mysterious organ
It would be more correct to affirm that, in reality, we know a tenth part of our thinking organ; or, rather, how it works. From the field of neuroscience we usually say that we speak of a brain from another brain, which will inevitably lead to errors of interpretation.
Also, if we used only 10% of the brain, what would the other 90% do? Would it be frozen? Thanks to evolution, most of our functions are very well developed, and that efficiency allows us to perform them most of the time.
This myth is, therefore, a fallacy without a scientific basis supported by certain esoteric doctrines such as scientology, which allow for alleged psychic powers that are still latent or excessive intelligence.
Among others, researchers Scott O. Lilienfeld, Steven Jay Lynn, John Ruscio, Barry Beyerstein and Josep Sarreten Grau, in their book 50 great myths of popular psychology: the most common misconceptions about human behavior (2009), have thrown it to the ground.
False claims and misinterpretations
So where did that hoax come from? Many believe that it was Albert Einstein who proposed it. Surprisingly, however, not a single record of such a claim exists.
Authorship has also been assigned to the American philosopher and psychologist William James, due to a distorted interpretation of a fragment of his article The energies of men (The energies of man, 1907). There, James said that “we make use of only a small part of our possible mental and physical resources.”
Later, Dale Carnegie, author of one of the first great best sellers self help, How to Win Friends and Influence People (1936), explicitly mentions the percentage in the prologue.
Arsenal of evidence against
Another possible explanation for the misunderstanding can be found in the very configuration of our brain. Neurons make up about 10% of nerve cells, while the rest are glial cells that support them. That is why it was thought that we would only use a tenth of our brain capacity.
However, there is clear evidence to contradict this assumption. Let’s see some of them:
Studies of brain damage show us that if we only used 10%, then these injuries would not affect the performance of the organ.
Evolution has caused us to consume more and more energy at the brain level, so we cannot use only a tenth of its capacity.
Positron emission tomography and functional magnetic resonance imaging have revealed that our brains continue to function while we sleep.
Using mapping techniques, it has been discovered that the organ has different regions to perform different functions. The percentage of use therefore adds up to 100%.
If 90% were turned off, metabolic studies that allow visualizing the active areas of the brain would obtain blank images, something that does not happen.
In those affected by certain neuronal diseases, the non-functional cells should not regenerate. Therefore, when doing the autopsy of the deceased, according to the false argument, we should verify that there would be no degeneration, since the vast majority of the organ would remain inactive.
Albert Camus said that “myths have more power than reality”. We must be careful with neuromyths, which distance us from reality and science, which still has much to contribute.