Do Humans Really Only Use 10% Of Their Brains?

There are some myths that are so beloved that, despite a mountain of irrefutable evidence to the contrary, they endure. Take one of the more well-known ones — that we humans only actually use 10% of our brains.

Although no one is exactly sure where this idea originated, it has been circulating for decades — at least since the early 1900s. Some credit psychologist and philosopher William James, who in his 1908 book "The Energies of Man," declared that humans are only utilizing a small portion of their full mental and physical potential (via Verywell Mind). Others erroneously credit Einstein.

Over the years, neuroscientists have continually explained the error of this view. Brain imaging scans show that the brain's regions are interconnected, and that most of them are active most of the time. Barry Gordon, a neurologist at Johns Hopkins School of Medicine in Baltimore, says, "It turns out though, that we use virtually every part of the brain, and that [most of] the brain is active almost all the time. Let's put it this way: the brain represents three percent of the body's weight and uses 20 percent of the body's energy" (via Scientific American).

If the 10% theory was true, it would mean that brain damage, or the removal of small amounts of the brain during surgery, would not be all that serious most of the time. But that's not the case. Instead, any amount of damage to the brain results in some kind of negative outcome (via Verywell Mind).

So why does this myth endure? According to Medical News Today, a 2013 survey found that around 65% of Americans still believe that we only actually use 10% of our brains. Hollywood screenwriters have made hay with the idea through movies like the 2014 film "Lucy," where the lead character is able to tap into her supernatural cognitive and physical powers (via The Conversation). And recent superhero-themed entertainment is just a stone's throw away from the concept.

It's appealing to think that we all have huge reservoirs of untapped brain power just waiting to be unleashed — but the reality is different. It's more likely that scientists only understand about 10% of how the brain works (via Scientific American). But researchers can tell us something else with much more certainty; when it comes to success in life, there's no substitute for practice and hard work.