Old wives' tale

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An old wives' tale is a wisdom much like an urban legend, supposedly passed down by old wives to a younger generation. It is so named for the alleged lack of sophistication of old wives. Today old wives' tales are also common among children's peer sex education in school playgrounds. Old wives' tales often concern pregnancy, puberty and nutrition.

Most old wives' tales are false and are used to discourage unwanted behavior, usually in children. Among the few tales with grains of truth, the veracity is likely coincidental.

[edit] Common old wives' tales

This list may require cleanup to meet Wikipedia's quality standards. This list is poorly defined, unverified or indiscriminate. Please help improve this list, prune it, or discuss it on the talk page. This article has been tagged since December 2006.

[edit] Eating carrots improves your night vision

Half-truth

Carrots do contain Beta-carotene, which is converted to vitamin A in the liver. Vitamin A helps to maintain healthy vision, but the carrots do not contain enough Beta-carotene to make any significant difference. This tale started in the Second World War when the British spread a rumour that their plane spotters were eating carrots to give them improved vision, concealing the truth about the invention of radar. Also the night fighter ace John Cunningham (21 kills) who was an early proponent of airborne radar in his Bristol Beaufighter, was nicknamed "Cat's Eyes" and alluded to have exceptional night vision because of his carrot eating.

[edit] Having sex standing up is a contraceptive

False

This is an example of an old wives' tale in peer sex education. Sperm are capable of swimming up the vagina, through the uterus to the fallopian tubes, where they may fertilize an egg, regardless of how a woman is positioned during or after sexual intercourse.

[edit] Chocolate causes acne

Half-truth

Chocolate does not cause acne in otherwise healthy individuals, but can have an effect if one is sensitive to a specific ingredient in chocolate, such as pasteurized milk or hydrogenated oil. This is an example of an old wives' tale used to discourage something (the large quantities of chocolate some children eat is unhealthy in other ways) by associating it with something that people are afraid of.

[edit] Masturbation causes blindness

False

This is an attempt to discourage masturbation (usually among young males) by associating it with blindness. In men, it is also associated with hairy palms and mental illness. Masturbation in females is sometimes said to cause infertility; this is equally false. Masturbation by a man may reduce fertility in the immediate future by using up some stored sperm, however this is not a long-term effect and not a reliable birth control: the sperm will be replaced naturally almost immediately.

The only correlation between the two is semen contains a large amount of zinc (as much as 0.25 milligrams of zinc to 1 mL of seminal fluid), and a deficiency in zinc (although nearly impossible to achieve solely by masturbating) will cause a decline in a person's vision.

[edit] Staying out in the cold without a coat causes pneumonia

False

Pneumonia is caused by bacteria such as Streptococcus pneumoniae. Variations on this tale include that someone who stays out in the cold will catch a cold or the flu (which are both known to be caused by viruses).

This tale was not debunked until fairly recently. As public awareness of the cause of disease increased, the tale evolved to include a number of different pseudoscientific explanations. One popular explanation is that a low core body temperature negatively impacts the effectiveness of the human immune system. This intuitively makes sense, as we know fever, an elevated core body temperature, is one of the immune system's defenses against infection. However, studies have shown^{[citation needed]} that there is no statistical correlation between lowered core body temperature and decreased immune response. Still, this old wives' tale, in its modern, pseudoscientific version, is still prevalent. Another version of this old wives' tale common in much of the world is that sitting by an open window or by air-conditioning will cause colds and pneumonia. (The standing water in some air conditioning systems may allow bacteria such as those that cause Legionnaire's disease to multiply. However, the chance of catching such a disease from air-conditioned air does not change depending on the distance one sits from an affected air conditioner.)

[edit] Stepping on a rusty nail causes tetanus

Half-truth

Tetanus is an anaerobic bacterium and can be transmitted via puncture wounds such as those received by stepping on a rusty nail. It is not the rust on the nail that causes the tetanus, however, but the dirt on the nail which may contain the tetanus pathogen; even a visibly clean nail (or other item) previously exposed to soil containing the bacterium can be the source of a tetanus infection.

Any wound that closes over at the surface before healing underneath can harbour a tetanus infection. Under such conditions the tetanus bacterium can flourish in a person not appropriately immunized. The tetanus bacterium is commonly present both on skin and in soil. Before the availability of a vaccine for tetanus it was necessary to keep potentially dangerous wounds open so that they would heal from the bottom up, thus preventing the anaerobic conditions that tetanus thrives in.

See also: Correlation implies causation (logical fallacy)

[edit] Watching television too much/up close will give you square eyes

False

This rumor is likely told to keep children from sitting too close to a television set or watching too much. Watching television for extended periods, and/or too closely, may cause fatigue, but it won't change the natural shape of the eye.

[edit] Other old wives' tales

• Habitual knuckle-cracking causes arthritis. False.[1][2]
• Drinking coffee reduces body growth. False. Coffee is a stimulant and may increase body growth, or, more likely, will have no effect.
• Taking showers or washing your hair when you are sick will rehatch a virus. False. Doctors prescribe cold water showers to bring down temperatures and nasal congestion. Viruses do not lay eggs or hatch from them.
• Chewing gum, if swallowed, remains inside your body for seven years. False. Chewing gum is excreted like any other undigested piece of food or stray object swallowed.
• Eating the crust of bread makes your hair curl. False.
• A pimple on your tongue means that you have lied. False.
• If your chin does not shine yellow when you hold a buttercup underneath it then you do not like butter. A variation of this tale is that if it does shine yellow, you'll be rich. Veracity would be coincidental, not causative.
• If you sneeze while someone else is talking, then what they are saying is true.
• Don't cross your eyes; they might stay that way. It is conceivable that the ocular muscles may become cramped or strained while crossing the eyes, but the probability is very low.
• If you make a face and the wind changes direction, your face will stay that way. False. This legend is prevalent among sufferers of Bell's Palsy and non-scientific health practitioners, but there is no causation.[3]
• If you go swimming less than an hour after you've eaten, you'll get cramps. False, but some scientists do in fact advise not to swim - or engage in any physical activity - for some time after eating, as the parasympathetic nervous system will kick in and start digestion, overriding the orders of the sympathetic nervous system which brings the body into the mode for physical activities.
  • This was parodied in the third Lemony Snicket book, The Wide Window, where the Lachrymose Leeches would eat you if you had not waited an hour after eating to swim.
• If you smell dandelions, you'll wet your bed. Coincidental if true.
  • This may refer to the dandelion's well-known diuretic properties, but one would have to consume them; smelling would have no effect. Nonetheless, the idea that dandelions cause bedwetting is seen in the English folkname for the plant ("pissabed") and the common French name for it (pissenlit).
• If you touch a toad, you'll get warts. False. Warts are caused by a virus, which is not transferable between species.
• If you feel a burning in your ears, it means that somebody is talking about you. A variation on this is that if you hear a ringing in your ears, someone is thinking about you. In India and former USSR countries, hiccups are a sign that you are being remembered by someone. In Japan, if you sneeze it means that somebody is talking about you behind your back. It is not possible to verify or disprove, so the adage is likely to persist indefinitely.
• If you have a stye, you must have read or watched pornographic materials. Coincidental if true.
• If your eyelids keep on twitching or ticing (blepharospasm), something significantly bad is going to happen to you soon. If the twitch occurs on the left eye, it means you will lose money, while a twitch on the right eye means you will be in some life-at-risk disasters. Unless the twitch is a highly unusual foresign of stroke, causation would be impossible to verify.
• If you feed chocolate to a dog, it will get intestinal worms. False, but the result of testing this tale may well be worse; chocolate intended for human consumption could kill the dog; one component of chocolate, theobromine, is a mild stimulant in humans, but quite toxic in some other animals, including dogs. However, dogs are able to eat a very small amount depending on their weight (though it is not advised to feed them any at all as too much will indeed kill them).
• If you eat cold milk and cherries together, it is toxic. U.S. President Zachary Taylor was believed to have died because he consumed milk and cherries together. Alternatively, any fruit consumed with milk will make you ill, because the acid in the fruit will make the milk curdle in your stomach. False, but the combination will cause discomfort in sensitive individuals.
• If you consume Pop Rocks followed by a carbonated drink, your stomach will explode and you'll die. False, but a very popular legend among children.
• Eating apples with cherries increases penis size. Coincidental if true.
• Eating cheese before going to bed will make you have nightmares. Eating any food before bed may disrupt the somnatic cycle, increasing the likelihood that sleepers will awake during REM sleep and remember their dreams.
• Not wearing slippers indoors will cause a range of ailments such as diarrhea, infertility, hemorrhoids, and pneumonia (common belief in many eastern European countries, including Poland, Bulgaria and Turkey). False.
• Drinking cold liquids or eating ice cream will cause one to have a sore throat. False. Ice cream is often given to tonsilitis patients after operations.
• Burying a chicken's foot in the garden cures common ailments. Coincidental if true.
• A crow making noise on your rooftop foretells the arrival of a guest. (Especially in Punjab) (In Norse mythology, the principal god, Odin, is accompanied by two ravens who can foresee the future.) However, Galliformes (game birds of the chicken family) predict death if perched on rooftops (especially in Northern Europe).
• If you take milk after eating rice, it can kill you. False.
• If you whistle at night, burglars will break into your house. (In many parts of Africa and Asia, this is usually modified with the nuance that evil spirits, ominous animals (such as snakes) or the angel of death may be drawn to the whistler. In parts of West Africa in particular, this tale is modified to include high pitched singing by a female or child, or the playing of wind instruments.)
• Brazilian old wives´ tales:
  • You will die if you eat mangoes and milk (created to avoid slave nightly plundering of farm areas during the slavery period)
  • Mirrors attract lightning during a storm; cover them to be protected (some truth here: metal attracts electric discharges more easily than most other materials, including water. Mirrors were mostly made of iron back then).
  • Pointing your finger to the stars will make warts grow on your fingers. No problems if you point to the moon or other planets, though.
  • A recipe will not work if you mix ingredients partly clockwise, partly anti-clockwise. (This is true only if one switches direction so quickly that the entire container is not fully stirred).
  • Wild boars will trample you to death in your sleep if you eat bacon in your bed past midnight.
  • You will grow worms on your stomach if you sleep when you're really hungry.
  • If a pregnant woman does not eat whatever food she craves at the time she craves it, the baby's face will resemble said food's shape.
  • Drinking soft drinks under sunlight may twist your mouth permanently.
  • Saying "Thank You" after someone says "Bless You" after sneezing will cause you to have bad luck.
  • People who can draw "perfect" circles are insane.
  • Ornamental elephants within your home are bad luck unless they face the door.
  • If you are hit on the knee cap and your leg does not twitch, you are insane.