"You know, you're only using 10 percent of your brain. Just imagine what you could accomplish if you used the other 90 percent!"
Chances are high that you have heard someone make a similar comment at some time or another. The popularly and widely spread belief that we only use or have access to 10 percent of our brain's power is often used to speculate about the extent of human abilities if only we could utilize our brain's full capacity.
In reality, this claim is 100 percent myth. We use all of our brain. The only instances where there are unused regions of the brain are those in which brain damage or disease has destroyed certain regions.
The Origins of the Myth
Researchers suggest that this popular urban legend has existed since at least the early 1900s. It may have been influenced by people misunderstanding or misinterpreting neurological research. The 10 percent myth may have emerged from the writings of psychologist and philosopher William James. In his 1908 book, The Energies of Men, he wrote, "We are making use of only a small part of our possible mental and physical resources."
The myth has perpetuated much like other urban legends. Movies depict characters capable of remarkable feats when the supposedly unused 90 percent of their brains are "unlocked." Well-intentioned people such as motivational speakers or teachers often cite the 10 percent myth as a way to demonstrate that all people should strive to live up to their full potential. Unfortunately, less well-meaning people have also used the myth to promote and sell products and services that they claim will unlock your brain's hidden abilities.
Debunking the 10 Percent Myth
Neuroscientists point out a number of reasons why the 10 percent myth is false:
- Brain imaging scans clearly show that almost all regions of the brain are active during even fairly routine tasks such as talking, walking, and listening to music.
- If the 10 percent myth were true, people who suffer brain damage as the result of an accident or stroke would probably not notice any real effect. In reality, there isn't a single area of the brain that can be damaged without resulting in some sort of consequence.
- We would not have evolved such large brains if we were only using such a tiny portion of them.
- The brain uses approximately 20 percent of the body's energy. It would make little evolutionary sense to have such a large portion of our energy resources utilized by such a tiny amount of the brain.
- Brain mapping research has yet to find any region of the brain that does not serve a function. "Numerous types of brain imaging studies show that no area of the brain is completely silent or inactive," wrote Dr. Rachel C. Vreeman and Dr. Aaron E. Carroll in a study of medical myths. "Detailed probing of the brain has failed to identify the 'non-functioning' 90 percent."
Unfortunately, the 10 percent myth remains both popular and persistent. It has been repeated in popular culture in everything from advertisements to television programs.
The next time you hear someone claim that we only use 10 percent of our brains, you'll be able to explain why this statement is not true. Not to say that human beings don't have amazing potential – we just use 100 percent of our brains to accomplish these remarkable feats.
Learn more about some of the most common myths about the brain.
Beyerstein, B. L. (1999). Whence cometh the myth that we only use 10% of our brains? In Sergio Della Sala. Mind Myths: Exploring Popular Assumptions About the Mind and Brain.. New York: John Wiley & Sons.
Vreeman, R. C. & Carroll, A. E. (2007). Medical myths. BMJ, 33, 1288.