Fact:

It is unclear how this myth started. Some attribute it to the 1908 writings of William James, an American psychologist who claimed that we only use a ‘small part’ of our brain in his book The Energies of Men. The myth is also attributed to Albert Einstein, but this has not been verified. So do we actually use such a small part of our brain? The answer is that even when performing very simple tasks, most of our brain is involved. Brain scans reveal that no part of the organ is inactive while its other parts are toiling away.

The myth has probably lived on because of the fact that humans can lose some brain tissue but still function properly. In reality, however, several pathways in the brain can be used for the same purpose, meaning if one were to fail, another could be resorted to. This is, however, contested by the fact that damage to small parts of the brain can have serious consequences, such as strokes. On the other hand, evolution has shown that the human brain has actually been growing. If only 10% of it were used, it seems unlikely that the brain would grow mass it did not need. Finally, the brain is known to be highly interconnected. Thus, it is impossible for only one of its compartments to be in use and for the others to remain inactive at the same time.

Promoting this type of knowledge as fact may appear attractive to those who maintain that our use of only 10% of the human brain indicates that it still has much potential to unveil. For some, the 10% may serve as motivation to work harder at reaching that remaining 90%. It is true that harder work will allow more synapses to develop in the brain due to stimuli, but this will not mean that new and unused parts of the brain will be used for the first time. If 90% of the brain were not used, then all the neuron pathways would be degenerated for lack of stimulus, which is clearly not the case.