Do we really only use 10% of our brain?

Our bodies use all of the brain power that is available. No one knows for sure where this myth that we only use 10% came from.

Do we only use 10 percent ouf our brains

Like dogs and children doing funny things on YouTube, some things find a way of going viral. The same can be said for some facts, such as how we only use use 10% of our brains. The biggest problem with this particular fact is that it isn’t really a fact. It turns out that statement is not true in any way, shape or form. What makes it even more remarkable is that no one really knows where this bogus claim came from!

Now having just lambasted this claim for having no factual support, what facts do we have?


This returns us to a subject of human cryopreservation where the brain is one of the biggest problems with cold storing a human body. The moment that you stop the heart beating or stop breathing then your brain suffers. No other organ in your body deteriorates quicker when starved. You can get serious irreversible brain damage after a little as a few minutes without enough oxygen getting to it. The brain is hungry and it is hungry because it works hard.

Anyone who has watched a wildlife documentary will know that nature is harsh. It is a non-ending arms race between hunters and the hunted. What this means is that nature does not do wastage. With that in mind, how could we have ever have evolved an organ with a 90% inefficiency? It makes no sense! People who look after animals will probably note how little we feed them in comparison to what we eat. Over-eating aside; the main reason for this is because we need more calories than many other animals to operate and one of the major drivers of this is the brain. Natural selection works best on expensive features that provide no extra benefit yet our super hungry brains endure. This means that it is a worthwhile investment.


Thanks to machines like MRI scanners it is now possible to watch the brain working. What we see from these images is that even the simplest of bodily movements require more than 10% of the brain to work.

Whilst there are still many things that we don’t understand about the brain, we do know that it has sections. Different parts of the brain deal with different things. There are parts devoted to vision, a part for smell, parts for emotion and memory and we use all of these different sections at different times depending on what is needed. These parts do a lot of talking between themselves too.

Mystery myth makers

So with all of this evidence showing that the brain is actually very well utilised, where on Earth did the myth come from? Unsurprisingly, no one seems to be taking credit for it. Often things like this come for misunderstandings of other facts; but without a culprit we can’t examine where such a misunderstanding would have originated.

One possible option comes from the fact that only 10% of the cells within the brain are used for processing power. Because the brain is so hungry for fuel 90% of the bulk within the brain is there purely to sustain the other 10%.

Now, you may say that this sounds very much like we are using 10% of our brains; but that really isn’t the case. This “white matter” that makes up 90% of the tissue in our brains is not capable of performing the same job as the “grey matter” in the other 10%. To expect it to would be like expecting your foot to think for you or butt to see like another pair of eyes (although I can’t imagine that anyone would want that view!).

Even if this white matter could start acting as grey matter, it would then need extra white matter to appear in order to keep it well fed enough to keep on working. So we are using the white matter too, it just does a different job. All the processing in your computer or phone comes from a tiny chip inside; the rest of that bulk is made up of other things that do equally important  but different jobs and your brain is similar. After all, you need more than 4 wheels and a seat to make a car.

So how much of the brain do we use?

What we have learnt is that whilst we don’t use all of the brain all of the time, we use all parts of it a different times.

Matilda’s Lab ©2018.

Matilda’s Lab is written to try and help adults explain complex science to children. Every effort is made to keep the content as accurate as possible but sometimes it is necessary to oversimplify things. However, if you think that anything here is categorically wrong then please get in touch so that a correction may be made.


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