Myth: We only use 10 percent of our brain
The myth pervades is often repeated by self-improvement gurus and Hollywood movies. But 'wasting' 90 percent of brain tissue would run contrary to all evolutionary principles.
From the outside, the brain is rather unremarkable: a lump of jelly-like fat weighing in at just under 1.4 kg.
Yet, it is basis for all our thoughts, feelings and actions and it has been called the most complex object in the known universe due to its network of 86 billion interconnected brain cells.
Because of that the brain fascinates us. We often look to neuroscience for explanations that help us figure out why we are the way we are.
Today arguments about how the brain works are drawn into discussions on education, personality, consumer behavior, and more.
But how much of that ‘pop-culture’ knowledge is actually supported by science?
Unfortunately, some of the most wide-held beliefs are closer to fiction than to fact and in the following article and two more to come, I will debunk three myths about the brain.
A myth repeated by pop-culture
One of the oldest and most pervasive brain-myths is that we only use a fraction of our brain and that we can develop exceptional cognitive abilities if we learn to tap into the ‘unused’ parts.
It’s a ‘nice’ myth, most people would be thrilled to boost their mental abilities by learning how to use their untapped potential. Perhaps that is why this myth is regularly repeated by advertisement, self-improvement gurus and Hollywood movies.
Its exact origin is unknown but like many brain-myths it may have started with the overinterpretation of real experimental findings: In the and 19th and early 20th century scientists found that large parts of an animals brain could be removed without a noticeable effect on behaviour.
This led the scientists to believe that a small part of the brain was enough for mental faculties to work.
Today we believe that the scientists did not test the animals thorough enough to notice all the effects their experiments had on the animal’s behaviour, but their findings may have started the believe that much of the brain lays unexplored.
Mini-series: Myths about the brain
In this mini-series Anke Ninija Karabanov will bust 3 common myths about your brain.
Anke is an associate professor in Integrative Physiology at Copenhagen University and is particularly interested in how the brain controls voluntary movement and how brain plasticity can optimally support skill learning.
This is the first article in this series
An unlikely mismanagement of the body’s resources
Today, clinical experience clearly contradicts the 10 percent myth: damage to small areas of the brain, for example caused by a stroke, can have devastating effects on the patients’ abilities.
Modern brain imaging methods also disprove the idea by showing that much of the brain is active during most tasks.
Also from an evolutionary perspective the 10 percent-myth is unlikely: Brains are expensive, they consume roughly 20-25 percent of the body’s entire energy budget.
If the majority of the brain was left to lie fallow this would be such an outrageous mismanagement of the body’s resources that an organism with this strategy is unlikely to have survived evolutionary pressure.
No secret store of untapped brain power
It is true however that the brain never activates all its 86 billion brain cells at the same time but the balance between cells sending signals and cells currently remaining quiet is crucial for the brains ability to transmit information.
The uncontrolled mass activation of brain cells is called a seizure and constitutes a serious medical problem rather than functional enhancement.
It is also true that there is a certain degree of redundancy in the brains architecture where several pathways serve similar functions but this ’safety mechanism’ is an important part of what makes our brain so resilient and adaptable.
So, unfortunately, there is no secret store of untapped brain power. We use all of our brain.