- The evolution of the human brain was only possible because it provided survival advantages and they must have been great since it consumes over 20% of the oxygen we breath while it only weighs 1,5% – 3% of our body weight. If we were to use only 10% of our brain than it would be extremely wasteful and such a disadvantage would be something selected against.
- Brain damage to far less than 90% of our brain would render us either physically dead, brain dead, or severely impaired. This shouldn’t be if we only use 10% of our brain.
- Strokes and head traumas that affect much less than 90% of the brain leaves people with serious deficits in functioning.
- Brain scans show that we use most of our brain even while performing simple tasks.
- Brain areas that are unused due to injuries or disease either degenerate or are taken over by neighboring brain areas.
Bottom Line: If we have more brain mass, it will be used; if it is not used, it will be discarded; and if we don’t have more of it, natural selection might select for it.
Myth Origin: William James, an American psychologist from the 19th and 20th century, said the average person only achieves a fraction (10%) of their intellectual potential. Misinterpretations have transformed potential into actual physical brain usage.
Lilienfeld, S. O., Lynn, S. J., Ruscio, J., and Beyerstein, B. L. (2009). 50 Great Myths of Popular Psychology: Shattering Widespread Misconceptions about Human Behavior. Chichester, UK: Wiley-Blackwell.