I have often heard it said humans “use only 10 percent of our brains.” (Why people make a point of saying this to me I’m not sure.) But for all the times I’ve run across this statement, no one has ever cited a source nor explained precisely what it means. Does it mean only 10 percent of the neurons ever fire at all, leaving the other 90 percent to atrophy? This would explain quite a bit about politics and college athletics, but it doesn’t seem appropriate for most functioning adults. As someone with an above-average number of active brain cells, perhaps you can unravel these mysteries. –Eugene Dillenburg, Chicago
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The 10 percent statistic has been attributed to pioneering psychologist and philosopher William James (1842-1910). I haven’t been able to confirm that he gave a specific percentage, but he did say “we are making use of only a small part of our possible mental and physical resources” (The Energies of Men, 1908). Anthropologist Margaret Mead supposedly said we use 6 percent, and similar numbers have been mentioned by various lesser known parties.
Obviously not all of the brain is in use at once. At any given time only about 5 percent of the neurons are active, the only sense in which the old saw is even close to true. (Good thing, too, or you’d have the equivalent of a grand mal seizure, a mental electrical storm in which all the neurons fire continually.) The parts of the brain are highly specialized, and some areas are more active than others depending on the task at hand. But all the parts do something, and it seems safe to say that over time you use pretty much all of your brain, just as most people use all their muscles to at least some degree.
Art accompanying story in printed newspaper (not available in this archive): illustration/Slug Signorino.
