Biomedical Engineering

We've long been told in school, on television, and through advertising that humans only use ten percent of their brains. You can walk up to just about anyone on the street and reiterate this claim without sounding (too) crazy. Usually, your audience will have heard of this assertion, even if they don't quite believe it (and just want you to go away).

The Origin of Specious

So the first question is: where did this urban legend originate? No one really knows for sure, but it has been attributed to several possible sources. In 1908, the psychologist Williams James wrote in The Energies of Men that "we are making use of only a small part of our possible mental and physical resources." James wrote at length about the undeveloped potential of the brain, so perhaps this myth grew from "10 percent of the brain's potential" to "10 percent of our brain."

The myth of the underutilized brain has also been attributed to Albert Einstein, who is said to have used it to explain his own formidable intelligence. The famed anthropologist Margaret has also been described as the source of the 10% myth. Finally, this claim is mentioned in the preface written by Lowell Thomas to of one of the best-selling self-help books of all time, Dale Carnegie's How To Win Friends And Influence People.

Psychics, Not Physicists or Physicians

The bottom line is that no one really knows where this myth came from. So why has it been so prevalent for so long? For decades, psychics have used it explain their powers while lamenting that everyone has intuitive gifts that they fail to use to their full capacity.

People also want to believe the 10% myth because of what it implies. Heck, who wouldn't want a dramatic increase in brain power? If we could only tap into that other 90%, maybe we too could develop psychic powers or become mathematical geniuses! Plus, if we're now only using 10% of our brains, we have a nice simple way to explain away our intellectual shortcomings.

This is Your Brain on Truth

There is overwhelming scientific evidence that we do indeed use 100% of the gray matter between our ears. Brain imaging technology clearly shows that even though certain simple functions only require small parts of the brain at a time, complex functions or thought patterns definitely use many parts. Even though every part of the brain isn't firing at every minute of the day, most regions are continually active throughout the day (and at night.)

Certainly, the brain has localized functions (e.g., right-brained vs. left-brained capacities), but the 10% myth takes the localization idea to the extreme. It implies that the 90% that we "don't use" is unnecessary. So, if the 10% myth were true, removal of or damage to the 90% unused part would be minor - or completely go unnoticed.

As head trauma patients, stroke victims, and Parkinson's sufferers would tell you, this is obviously not the case. Losing a whole lot less than 90 percent of the brain due to trauma or disease can have disastrous consequences. Researching the effects of head injury has shown that there doesn't seem to be any area of the brain that can be destroyed by a stroke or head trauma without leaving the victim functionally impaired.

So the next time you hear people say that they only use 10% of their brain, you can either take the high road and set them straight, or simply ask them "So which part of your brain don't you use?"