Who said we only use 10% of our brain?


Surely you have heard the famous phrase that we only use 10% of our brain. In fact, a third of my psychobiology students believe so, and another significant percentage “I don’t know, no answer”. This is one of the most widespread hoaxes in the field of neuropsychology. And when we meet him, we think: “And 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 be harnessed in some way, superhuman powers would be unlocked. I don’t keep doing spoilers.

In this article, I intend to debunk this neuromyth and reassure you: we all use our brains, but obviously not all of them at the same time. Because, effectively, we use 100% of an organ which represents only 2% of the weight of the body and which requires 20% of the energy consumed. It would be something like saying that someone only uses 10% of their leg muscles to run. Use absolutely all of them, but not to their full capacity.


The brain, a mysterious organ

It would be more correct to affirm that in reality we know a tenth of our thinking organ; or rather how it works. In the field of neuroscience, it is generally said that we speak of a brain of another brain, which will inevitably lead to misinterpretations. Moreover, if we only used 10% of the brain, what would the remaining 90% do? Would it be frozen? Thanks to evolution, most of our functions are very well developed, and this efficiency allows us to perform them most of the time.

This myth is therefore a sophistry without scientific basis supported by certain esoteric doctrines such as Scientology, which admit alleged still latent psychic powers or excessive intelligence. Among others, researchers Scott O. Lilienfeld, Steven Jay Lynn, John Ruscio, Barry Beyerstein and Josep Sarreten Grau, in their book 50 Big Myths of Folk Psychology: The Most Common Misconceptions About Human Behavior (2009), knocked him down.

False statements and misinterpretations

So where does this hoax come from? Many believe it was Albert Einstein who came up with it. Surprisingly, however, there is not a single record of such a claim.

Authorship has also been attributed 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 only use a small part of our possible mental and physical resources”. Later, Dale Carnegie, author of one of the first great bestsellers 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 lies in the very configuration of our brain. Neurons make up about 10% of nerve cells, while the rest are glial cells that support them. This 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 on brain damage show us that if we only used 10%, this damage would not affect the performance of the organ.
  • Evolution has made us consume more and more energy at the level of the brain, so we cannot use only a tenth of its capacity.
  • Positron emission tomography and functional magnetic resonance imaging tests have revealed that while we sleep, our brain continues to function.
  • Using mapping techniques, it was discovered that the organ has different regions to perform different functions. The utilization percentage adds up to 100%.
  • If 90% were turned off, metabolic studies to visualize active areas of the brain would get blank images, which doesn’t happen.
  • In people with certain neuronal diseases, non-functioning cells should not regenerate. Therefore, during 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 wary of neuromyths, which distance us from reality and from science, which still has a lot to contribute.

Character font: Sandra Sánchez Muñoz / THE CONVERSATION

Reference article: https://theconversation.com/who-said-we-only-use-a-10-of-our-brain-183266

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