I mildly curse our popular culture, science fiction niche genre product and our education system for insuring/ensuring that the myth of human beings, on average, only using “10% of our brains” endures.

In comic books the narrators, and thus the writers, love to assert that the average human being is so crippled to a portion of his ultimate physiological capacity so it can assert that a villain or antagonist uses portions of the extra percentage in order to insist that the character is beyond a normal human or simply not a normal human. This is also used to explain extra abilities or special abilities in characters that are not supposed to have superhuman powers yet have abilities beyond that of normal humans. Two examples of this cliche is The Key as written by Grant Morrison, and Deathstroke The Terminator as presented by Brad Meltzer.

The Key is a very old villain for the Justice League of America, having been co-created by Gardner Fox, however the character as relevant to the argument was written for the cliche in JLA issue numbers 8 and 9 which was reprinted in JLA: American Dreams
. Grant Morrison revamped the character in a way to render him more dangerous. Expanding beyond the “10%” granted special senses, extra senses for the purposes of disabling the Justice League and then wear the universe so he could reshape, repurpose the universe.

Brad Meltzer wrote the supersoldier character Deathstroke the Terminator as an antagonist to some of the 1970s Wein/Conway/Englehart/Dillin “Satellite era” members of the Justice League, attaching the line that Deathstroke uses “90%” of his brain, in the comic book Identity Crisis
event/story. I like how Mike Haselhoff phrases it.

Deathstroke is really quite a scary villain for a lot of reasons, one of those being that controlling 90% of his brain function makes him pretty difficult to define. I’m not sure anyone could tell me exactly what potential 90% brain function would unlock.

Part of my problem is that I cannot exactly tag Brad Meltzer with the responsibility as I cannot determine where the idea of Deathstroke’s 90% brain capability comes from. I just know that it is stupid. I would like to scapegoat Meltzer because the scripting of the Terminator’s appearance(s) in the Identity Crisis story is poorly-written (and as a fight scene, poorly scripted) but I will not assign blame falsely. Ultimately both characters in my examples were created and used for decades before the stories I cite.

Alas this use as a cliche in genre fiction just reinforces the illusion in so many minds that the human brain has extra capacity for us to tap. Whenever someone asserts the idea I get annoyed and I hope that there is no damage done beyond annoyance but I am not comforted.

The idea that we only use 10% of our brains is probably such an enduring myth because it’s comforting to think we have spare capacity. The ‘unused’ 90% could take up the slack after brain injury or offer the possibility for miraculous self-improvement.

It is time to remove the comfort and slap some bricks into the pillowcase.

Boring, tedious, but unavoidable facts

Unfortunately there’s four good reasons it’s almost certainly false (Beyerstein, 1999):

  1. If we only use 10% of our brains then damage to some parts of our brains should have no effect on us. As any neurologist will tell you, this is patently not true.
  2. From an evolutionary perspective it is highly unlikely we developed a resource-guzzling organ, of which we only use 10%.
  3. Brain imaging such as CAT, PET and fMRI shows that even while asleep there aren’t any areas of our brain that completely ‘switch off’.
  4. Parts of the body that aren’t used soon shrivel and die. Same goes for the brain. Any neurons we weren’t using would soon shrivel and die.

The structure of the brain and its metabolic processes have also been carefully examined, along with the diseases that afflict it. None of this work has suggested there is a hidden 90% that we’re not using. Unfortunately. Anyone who still maintains we only use 10% of our brains after this fusillade of fact has to come up with a counter-argument for each one of these.

Naturally another reason the myth comes up now is because the phrasing has existed in one form or another for awhile.

The actual confirmed first written sightings of this myth, though, is in a 1940s advert for the book Cold Comfort Farm by Stella Gibbons (Wanjek, 2003, p.21):

“What’s holding you back? Just one fact — one scientific fact. That is all. Because, as Science says, you are using only one-tenth of your real brain-power!”

Whatever its provenance, the 10% myth is certainly a slippery customer. The reason is two-pronged: first, it’s impossible to prove something doesn’t exist and second, people like to believe it.

Of course! “Science” says! That also explains why so many individuals sadly believe in anthropogenic “global warming”/”climate change” and insist in executing vast collective political processes to transform the planet into some idealized stage of being.