Dandelions make you wet the bed, goldfish have a thirty-second memory and more "facts" that are actually just fiction...
10,000-hours of practice will make you an expert
The Deceived Wisdom is that a 10,000-hour rule applies to become an expert or virtuoso. The idea was made popular by Malcolm Gladwell apparently based on the research of psychologist Anders Ericsson of Florida State University. Ericsson never mentioned 10,000 hours and says there is more to perfection than simply putting in the hours. Most people do a relatively limited amount of practice to ‘perfect’ their art, whether wielding a cricket bat, playing chess, singing or programming computers. It can make you perfectly competent – but not necessarily excellent.
Picking Dandelions will make you ‘wet the bed’
Dandelions do contain a mild diuretic, a natural chemical that increases the production of urine. However, simply picking the flowers will not lead to the ingestion of sufficient quantities of this chemical to cause uncontrolled nocturnal urination. Ironically, despite the origin of the English name for the plant being old French dent-de-lion, ‘lion’s tooth’, the modern French for this species (Taraxacum) is pissenlit, the English folkname is ‘piss-a-bed’.
Shaving makes hair grow back thicker
Hair is dead tissue, so shaving can have no effect on the shape or size of the follicles from which the hair grows. If this deceived wisdom were true, bald men might shave their heads regularly in order to remedy their lack of cranial hirsuteness.
Lightning never strikes the same spot twice
The maintenance team at the Empire State Building in New York City will testify that their building is struck by lightning at least twenty-five times each year. Other high points on the landscape suffer an equally discouraging succession of bolts from the skies, and there are several reports of people who have survived multiple strikes. Worldwide, there are about thirty lightning strikes that reach the ground every second.
You could drown if you swim right after eating
Although the gut does divert blood to help with digestion, there is no evidence that this has ever affected anyone’s ability to swim, and there is no valid official recommendation on not eating before swimming from any sports or safety organization. Of course, some people find exercising after eating uncomfortable, but it is not physically dangerous. Children will often jump down from their place at the dinner table and be running, swimming, bouncing and jumping without any ill effects.
Most of the body heat you lose is through the top of your head
If you are brave enough to go outside naked on a cold day, the rate of heat loss from any part of your body will be approximately the same from any given area. However, on cold days we tend to wrap up warm with trousers, tops, shirts, pullovers, coats and woolly socks. If you don’t add a hat to the mix, then the rate of loss of heat from your head will, of course, be higher than from your other covered body parts, but put on a thick, insulating hat and you will stay cosy and warm. Incidentally, going outside with wet hair on a cold day will not increase the risk of your catching a cold. Exposure to the cold-causing virus is the only thing that increases that risk.
Teflon was a spin-off of the Space Race
The non-stick plastic polytetrafluoroethylene (Teflon ) was invented serendipitously in 1938 by Roy Plunkett of Kinetic Chemicals in New Jersey. It was used in engineering and for ‘non-stick’ cooking utensils long before the space race.
Your tongue is divided into areas for tasting sweet, sour, bitter, and salt
Although popular science books and school textbooks often show a ‘map’ of the tongue with the sweet taste buds at the tip and bitter at the back, and other regions demarcated for salt and sour, this is a misconception. The relative sensitivity of different regions varies insignificantly, a fact known to scientists since the work of Virginia Collings in 1974. All areas on the tongue can taste all the different types of taste, including the fifth taste known as ‘umami’, or ‘deliciousness’, knowledge of which emerged from research into Japanese cuisine. Scientists also think we might have a taste for ‘fat’.
Goldfish have a thirty-second memory
This particular piece of deceived wisdom has been debunked on several occasions by scientists and others who have trained goldfish to swim through mazes, push levers to obtain food and carry out other tasks. If their memory lasted just a few seconds, they simply wouldn’t remember the route or what to do to get the food.
Your fingers go ‘pruney’ after a long bath because they absorb water
Until recently it was assumed that the reason your fingers and toes wrinkle up temporarily when you are in the bath or go swimming is that water is absorbed by the skin, and this causes the different skin layers to buckle. However, since 1935 scientists have known that the fingers of people with damage to the median nerve do not go completely pruney. Researcher Mark Changizi has put forward a theory that the wrinkled-finger effect is a reaction by the brain to our being wet whichmakes our fingers and feet wrinkle up to get a better grip on surfaces covered by the water, like the grip of a car’s tyres in the wet.
Deceived Wisdom by David Bradley is published by Elliott & Thompson £11.99 hb/ebook available.