Most of us at one point or another will have heard that ‘we only use 10% of our brains’. In fact, there is a whole genre of films and TV shows devoted to this concept and what we could achieve if we were able to access the whole 100%!William James, known as the ‘father of psychology’ in the US, and Boris Sidis, another well-known psychologist, developed what is known as their ‘Reserve Energy Theory’ which posits that most humans will only realise a small fraction of their intellectual potential, an idea that has been picked up with gusto by many self-help ‘gurus’ since the 1920s. During that time, the ‘small fraction’ of potential James and Sidis believed people reached was given the value of 10%. This is believed to be the origin of the myth that we only use 10% of our brains.
This origin story of the 10% myth is contested, with others believing that the 10% number came from the belief that in our brains the glial cells outnumber our neurons 10:1. This has recently been challenged with research showing the ratio is closer to 1:1. Another catalyst for the idea that we’re only harnessing a small part of our brains are stories of people who have been discovered to only have a small portion of their physical brains and yet live relatively normal lives. This has been reinforced as recently as 2007, when a man who had been complaining of weakness in his left leg found, through a brain scan, that he was missing most of his brain due to hydrocephaly (water on the brain). The man, who did not have any visible handicaps, had much of the space in his skull taken up by fluid. This led to many assuming the brain must have significant redundancies, as with other organs, and that in order to function at an ordinary level humans are only using a small part of the brain. Due to the pop-culture interest in this idea, the media picks up these rare stories sharing them widely and reinforcing the myth that we only use 10% of our brains.
Given what we know about the cases in which people only have a small portion of what we would normally consider a complete and healthy brain, how true is the idea that we only use 10% of our brains? First, it’s necessary to evaluate the idea - when it’s said we only use 10% of our brains, is that the physical brain i.e. the neurons, or regions of the brain? Or is it 10% of the brains overall processing capacity?
Using neuro-imaging, we have been able to track and map activity in the brain. On the surface, some neuro-images appear to show that we do only use small portions of our brain, supporting the myth. Yet neuro-imaging typically shows ‘hot spots’ within the brain as opposed to wide-spread activity. These images are used to try and understand how specific regions of the brain behave while undertaking specific activity. With these images, it’s important to know that the ‘base-line’ activity within the brain has often been filtered out so that you can see which specific parts of the brain are the most active when undertaking certain activity.
Further, as we’ve discussed previously, while small parts of our brain are typically responsible for very specific activity or types of thought, our brains largely function as a whole. Neuro-imaging has shown that when you’re engaging in creative thought, or solving a maths puzzle, you’re using huge portions of your brain. Consequently, the idea that 90% of our physical brain is dormant or not being used is quite problematic.
While the myth that we only use 10% of our brains is challenging, our brains do have remarkable abilities. Take neuroplasticity, the brains ability to adapt and rewire itself. This is a remarkable function or our brains, which is why people, (most commonly young people), who through illnesses like hydrocephaly lose or never develop a large part of the brain, are able to function and live relatively normal lives. It’s not that we’re only using 10% of our brains and therefore these people only needed that much to being with, it’s more likely that through an amazing brain function like neuroplasticity, the brain rewired itself to function accordingly.
With regards to special abilities, there is certainly evidence that some people have innate special abilities, a classic example being Mozart who reportedly wrote is first symphony at eight and went on to be arguably one of the greatest and best-known composers throughout history. While it is clear that Mozart had natural gifts, he also devoted his life to this pursuit. It is reported that from a very young age he was engaged in music, watching his older sister learn and being encouraged through games to learn and play with his father. This love of music and receipt of continual practise was something Mozart experienced throughout his life. While less exciting than thinking of people like Mozart as a natural genius, it’s important when looking at these modern and historical figures, to remember that natural abilities often give way to passions resulting in years of practise through which we lay down new pathways in our brains, rewiring them to better perform a certain function. Anyone who has learnt a language or an instrument will know that if you stop practicing that skill it will very quickly fade. This is because if we don’t continue to lay down pathways in our brains it will be efficiently reassigned. When we think about our brains and what our potential is, perhaps we do only typically reach a small amount of our potential, yet this isn’t because we haven’t unlocked a secret part of our brains, it’s more likely to do with how we choose to spend our time. You can have the potential to become particularly skilled at something, you simply need to devote the necessary time to achieving it.
So, when it comes to how much of our brains we actually use, the research shows that regarding the physical size of our brains, even at rest, our whole brains light up with activity. Although there have been cases of people suffering damage to the brain, or missing part of it, brain functions like neuroplasticity can rewire our brains to function differently, and this does indicate that we only use that much of our brains to start off with. In regards to special abilities, although some people are naturally more skilled than others, typically this ability gives way to a passion and years of practice which enhances the skill by laying down new pathways and reinforcing existing pathways in our brains. Our brains are incredibly complex and we’re still learning a lot about them every day, yet we do know that we’re using more than 10% of them!