The myth that we only use 10% of our brains

You've almost certainly seen or heard this claim, even from perfectly sensible and intelligent people: "We only make use of 10% of our brains - if only we could learn to tap into the other 90%..." A friend tried to convince me of it just the other day. Unfortunately (or perhaps fortunately), it is just plain wrong.

It is hard to even know where the claim came from. Early psychologist and author William James claimed in a 1907 article in the journal Science that we only use part of our mental resources, although he did not mention any percentages, nor did he offer any evidence for his claim. The figure of 10% was mentioned in Dale Carnegie's 1936 book "How to win friends and influence people", but only as an unsubstantiated piece of conventional wisdom. It has even been misattributed to Albert Einstein. Somehow, though, over time, it became a widely quoted "fact" in all sorts of articles, TV programs and newspapers. Health, lifestyle and self-help gurus (and even more-or-less respectable psychologists) avidly picked up on it as a means of touting their own particular brand of snake oil, and now apparently 65% of Americans believe it to be true.

However, as explained in simple terms in Scientific American among other places, the fact is that most of our brains are in use most of the time, even when carrying out the most basic of tasks, and even when sleeping. Over the period of a day, virtually 100% of our brains have been in use at some point, and fMRI testing at the prestigious Mayo Clinic has proved this. Hell, even TV's Mythbusters show has disproved the 10% myth. The "10% of our brains" claim now permanently resides - or at least SHOULD do - in the Urban Myths section.