Brain Myths, Debunked

No, you don't use only 10% of your brain — and you aren't 'left-brained' or 'right-brained' either. A tour of the most popular brain myths and what the science actually says.

Few subjects attract as many myths as the brain. Some began as misunderstandings of real research; others were invented to sell something. Here are the most common.

"We only use 10% of our brains"

False. Brain imaging shows activity across the whole brain over the course of a day, and even small areas of damage — from a stroke, for example — can have serious effects. A brain that wasted 90% of its tissue would be an enormous evolutionary extravagance for an organ that uses a fifth of our energy. The myth's origin is unclear; it may come from misquoted remarks by early psychologists and was popularised by self-help writing.

"Left-brained people are logical, right-brained people creative"

Partly true at the level of specific functions — language is usually concentrated in the left hemisphere, some aspects of spatial attention in the right — but there is no evidence that individuals are dominated by one side. A 2013 University of Utah study of more than 1,000 brain scans found no sign of "left-brained" or "right-brained" people. The two hemispheres work together constantly through the corpus callosum.

"Brain cells never regenerate" and "Alcohol kills brain cells"

Most neurons are not replaced, but the brain changes throughout life: synapses form and vanish, and in some species — and possibly in the human hippocampus — new neurons are born in adulthood. Heavy drinking does damage the brain, but mostly by harming connections, white matter and nutrition (such as thiamine deficiency), rather than by simply "killing cells" with each drink.

"Memory works like a video recorder"

Memories are reconstructed each time they are recalled, which is why they can change, blend and even be implanted. Confident memories are not necessarily accurate ones.

Others worth dropping

Listening to Mozart does not make babies smarter (the original 1993 effect was small, short-lived and in adults). Teaching to "learning styles" — visual, auditory, kinaesthetic — has not been shown to improve learning. Bigger brains are not straightforwardly smarter. And the "lizard brain" idea — that we have a reptile brain wrapped in a mammal brain — is an outdated model of evolution.