Mar 6

Mar 6 Sassy Mythbusting: Do We Use Only 10% of Our Brains?

There is a myth out there that humans only use 10% of their brain. Although there may be some people in your life that you believe to use even less of their brain than that (I kid, of course!), this is but a myth. Healthy humans actually use all parts of the brain.

Do We Only Use 10% Of Our Brains?

There is a prolific myth lingering out there in popular culture that humans only use 10% of their brain.

Understandably, back in the olden days of yore, the brain was a bit of a black box. But nowadays, we have really cool technology like PET (Positron Emission Tomography) scans and fMRI (functional Magnetic Resonance Imaging), that have rocketed forward our understanding of the brain over the past few decades. Based on these imaging techniques, we can see that all of the brain is used in healthy humans.

The reality that has been discovered over the past few decades is that the brain is a complex network of tissue that is always ‘on’ and multitasking on numerous functions, between intaking and sorting through sensory information, conscious thought, possessing emotions, engaging in decision-making, monitoring and executing body functions, etc. There are regions more specialized than others but it doesn’t mean the rest of the brain turns off when certain regions are being drawn upon for specific tasks. We use 100% of the brain even when we sleep!

So now that we have evidence that we use all of the brain, why is this myth still a thing?

Myth Persistence

There is a lot to be said for hearing something over and over again. In fact, illusory truth effect describes our tendency to believe false information is actually correct after repeated exposure. So the fact that this myth is repeated so often is likely contributing to its perpetuation. The myth appears to be over a century old, before it was possible to fully confirm or deny its validity through scientific evidence (though now we have very clear evidence that it’s not true at all). Worryingly, a study found that 50% of teachers believe the 10% myth to be true. But that’s better than other research that shows 65% of Americans believe it’s true (5 percentage points more than the amount of people who believe in evolution!).

Additionally, the myth is super convenient if you are trying to market some kind of self-help solution to UNLOCK THE POTENTIAL OF YOUR BRAIN!!!! It also aligns very nicely with a fantasy of having superhuman mental abilities (think of all the game shows you could win!!!).

So beware of any book or program that uses this myth as it’s basis. You’re already using 10% of your brain. You’re awesome.

Really… it’s not True

We all have people in our lives where it seems that quite clearly they are using 10% (or less) of their brain. But seriously, it’s still a myth. Here are a few other reasons why the 10% myth cannot be true:

● There is no data or evidence to support this 10% of the brain idea.

● If you only use 10% of your brain, and your brain was already engaged doing a task, would you just complete miss or ignore other things? Like if you were focused on driving down a road, and a pedestrian stepped out in front of your vehicle, would that just be… it?

● The myth would suggest that if you removed the other 90% of your brain, you’d be just fine since you’re only using that 10% of it anyway. However, we know that even small damages to the brain can cause large issues (i.e., in the case of strokes, Parkinson’s, etc. which impact much less than 90% of the brain) so this 10% rule doesn’t make sense.

What About Our Capacity for Storing Memory?

Memory, on the other hand, well maybe we could get a number close to 10% with the concept of ‘used space’. The way that our brains store memories long term with each neuron forming about 1,000 connections to other neurons, leads to about a trillion connections. Neurons combine and work together to store many memories at a time, exponentially increasing the brain’s storage capacity to an estimated 2.5 petabytes (i.e., a million gigabytes) of “memory space”. My favourite estimate about our brain’s capacity for memory is that if our brain acted like a video camera recording data constantly, it would take 300 years to fill up (obviously memory and senses don’t work like that… it’s just a metaphor). But still, all the while, 100% of the brain is being used all the time, involved in the process of forming memories alongside a bunch of other functions.