It’s a myth that we only use 10% of our brains

The idea that humans only use 10% of their brains has been circulating in popular culture for many decades. In fact, Encyclopedia Britannica says the theory is one of Hollywood’s favorite bits of pseudoscience.

For example, the 2014 film “Lucy” uses the widely held belief as a major plot device. In the film, Professor Samuel Norman, who is played by Morgan Freeman, says during a lecture: “It is estimated most human beings only use 10% of their brain’s capacity. Imagine if we could access 100%. Interesting things begin to happen."

VERIFY viewer Lucia asked our team if this theory is true or false.

THE QUESTION

Do we use only 10% of our brains?

THE SOURCES

• Association for Psychological Science
• Organization for Economic Co-operation and Development (OECD)  
• Beth Israel Lahey Health Winchester Hospital in Winchester, Massachusetts
• Eric Chudler, Ph.D., neuroscientist, research associate professor and executive director of the Center for Neurotechnology at the University of Washington

THE ANSWER

No, we don’t use only 10% of our brains.

WHAT WE FOUND

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There is no scientific evidence to suggest that humans use only 10% of their brains, according to Eric Chudler, a neuroscientist and professor at the University of Washington. Instead, all existing evidence shows that people actually use 100% of their brains on a daily basis.

“We use all of our brain. We don't use only 20%. We don't use only 10%. We use 100% of our brain,” Chudler told VERIFY. “Experimental and clinical evidence suggests that there's no part of the brain doing nothing.”

According to Chudler, scientists often use brain imaging techniques, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) scans, to look at how the brain is functioning.

"When you look at a brain image, all parts of the brain are doing something — there's no part of the brain that's just sitting there inactive. So we can use brain imaging and literally see that the brain is active," Chudler said.

The notion that humans only use 10% of their brains is one of the “most persistent and widely spread brain myths,” according to the Organization for Economic Co-operation and Development (OECD). The Association for Psychological Science and Beth Israel Lahey Health Winchester Hospital also call the popular belief a myth on their websites.

Chudler says the origin of this myth is not quite known, however, there are a couple of theories behind where it may have originated. Some people attribute it to a statement made by Psychologist William James in 1907.

“Psychologist William James wrote in a very influential book that we only use part of our possible mental or physical resources, back in, I believe, the early 1900s. But he never put a percentage on it,” Chudler said. “Some people say that Albert Einstein said it. Some people say that Margaret Mead said it. But I've never been able to find a quote attributed to Albert Einstein or Margaret Mead.”

The Association for Psychological Science also notes that James in no way claimed that humans only use a small portion of their brains. Instead, they say James was observing how decorum, social norms and routine fail to engage all of people’s resources.

“His statement is actually consistent with what we now know about attention and flow states, but James clearly was not claiming that most people perpetually use only 10% of their brainpower,” the Association for Psychological Science says.

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