You've probably heard the popular claim that humans only tap into about 10 percent of their brain power. Neurologists have debunked that urban legend countless times in the past, with many calling it a laughable myth.
But for whatever reason, people are still choosing to believe it. The entertainment business might be to blame- at least in part.
In the new sci-fi thriller "Lucy," which hits theaters this weekend, Scarlett Johansson plays a woman who is implanted with a mysterious drug that exponentially increases her mental capabilities, according to IMDb.
And other recent releases like "Limitless" and "Transcendence" perpetuate the idea we only use a fraction of our brain's computing power. (It also makes for a good pick-up line in "Wedding Crashers.")
But as "Lucy" starts to make people question this idea's validity once again, doctors are reiterating that it just doesn't make sense.
"It's not true, absolutely not. We're using 100 percent of our brain all the time," Dr. David Samadi explained on Fox News.
No one knows exactly where this popular "10 percent" myth originated, but a professor of clinical neuropsychology at the University of Cambridge told the Belfast Telegraph the 10 percent figure was widely circulated for the first time in the 1936 best seller "How to Win Friends and Influence People."
She claims the author probably made up the figure to prove a point in the book, seen here on Amazon.
But that 10 percent number could also come from a misunderstanding of how most of our brain cells work.
"What's interesting about this is that, if you get a brain scan, you would see that maybe about 10 to 15 percent of your brain is extremely active," Dr. Samadi says.
To be clear -- the entire brain is always active. As LiveScience pointed out back in 2010, brain scans have shown people use all of their brain, though it is true we don't use all of it at the same time.
But years of studies like that don't seem to be getting through. A survey sponsored by The Michael J. Fox Foundation for Parkinson's Research last year found 65 percent of Americans still believe people only use 10 percent of their brains.
So why won't people let this myth go already?
A health writer for the BBC says it might be because it's a pretty encouraging idea. "Maybe it's the figure of 10 percent that is so appealing because it is so low that it offers massive potential for improvement. We'd all like to be better. But, sadly, finding an unused portion of our brains isn't the way it's going to happen."
Hopefully, the film industry will catch up with the world of science soon. But hey, at least the myth makes for a good movie night.
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