26 Things We Used To Think Are True (But Aren’t)

Some myths we were told or heard as children that we have since learned are untrue. Perhaps we heard these lies in cafes, shopping lines, bars, or even at school.  We compiled a list of 26 things we used to think were true but weren't. 

1. Race Determines Genes 

Contrary to popular belief, our genes are not defined by our racial profile. The National Human Genome Research Institute (NHGRI) suggests that humans share 99.9% of the same genes regardless of race, and even the 1% remainder has no significant variant markers. Moreover, a 2002 NHGRI study found more genetic diversity in Africans than between Africans and Eurasians.

2. Stress Causes Hypertension

According to the British Medical Journal, stress is not the sole reason for hypertension, better known as high blood pressure. While stress can trigger a temporary spike in blood pressure, genetic factors and bad lifestyle choices such as obesity have an overall worse effect on our pulmonary pathology.

3. Aristotle Disproved the Flat Earth Theory

In modern times, there are some curious theories on the spherical nature of our planet, though the consensus remains that we live on a globe. However, one of society's myths is that we used to believe the Earth was flat until Aristotle suggested we were wrong. Pythagoras first breached the subject of a spherical world — albeit mainly on aesthetic grounds.

4. We Catch Colds From Cold Weather 

When winter comes around, the common cold always spikes. While mothers still fret about their children catching hypothermia from cold air, their fears are misguided. However, the data show that we are more likely to catch a cold because we spend more time indoors during the colder months. Just ask anybody in the tropics whether they had a cold recently- you would be surprised.

5. Lightning Never Strikes Twice

We are led to believe through common phrasing that lightning will never strike the same place twice, but we are wrong. Lightning is more likely to hit the same thing numerous times. According to Live Science, the Empire State Building once took eight lightning strikes in only 24 minutes.

6. Tourette Syndrome Leads To Swearing

While some Tourette syndrome sufferers may have the coprolalia swearing tic, most don't blurt out random cuss words or dark inner thoughts. Popular culture dictates that we see only the worst traits in a condition. According to the Child Mind Institute, Tourette syndrome has more layers to it than the inability to control one's words.

7. Possums Sleep Hanging Upside Down

We've all seen cute photos and cartoons, but you would be lying if you told your children that possums sleep hanging by their tails. Possum tails are incredibly strong- powerful enough to hold the mammals' bodies upside down temporarily, but possums sleep on the ground, in the undergrowth, and near a water source.

8. Juice Cleanses Detoxify Our Bodies

While juicing is not bad for us, delivering many essential vitamins, we would be better off eating the solid versions. Juicing breaks down the digestive fibers in fruit, so if anything, they will be less healthy in this format. Some sugary fruit juices even contain as much sugar as soda-based drinks.

9. Knuckle Cracking Causes Arthritis

Until recently, many thought that cracking knuckles over a long period caused arthritis. However, few significant studies show evidence of this, and a preponderance of studies claim it doesn't. However, it isn't all good news: scientists have found that other damage, such as swollen joints or weakened grip, may occur.

10. Ostriches Bury Their Heads in Sand

The Office for Science and Society at McGill University explains that the myth of ostriches burying their heads in the sand comes from Roman times. The idea that any animal willingly buries its head in the sand is illogical, considering most air-breathing birds would suffocate in this position. Ostriches lie with their neck and head resting on the ground if they detect a predator nearby.

11. MSG Makes You Sick

12. A Falling Penny Can Kill

How many Americans have been told that a penny dropped from the top of the Empire State Building can crack a skull? This scenario is untrue for several reasons: the drag force caused by air resistance would halt the coin's acceleration after 50 feet, says Scientific American. The coin would “flutter like a leaf” as the air cushioned its fall, meaning any impact on a skull would be more like a painful sting.

13. Sugar Causes Diabetes

For many years, we were told that too much sugar can cause diabetes. However, while sugar and carb consumption are directly linked to obesity and heart disease, the American Diabetes Association says there isn't enough evidence to support the sugar connection. If anything, a salt-heavy diet is far worse: NIH also published a study that found people who add extra salt to their meals were more likely to develop type-2 diabetes.

14. Goldfish Have Three-Second Memories

So many pieces of everyday trivia are ignorant, and none are more silly than goldfish having three-second memories. It isn't clear where this myth began, but since the '50s, most experts have known goldfish have impressive memories. Contrary to societal belief, goldfish are intelligent species whose memories can last years.

15. Television Screens Damage Our Eyes

One can imagine this myth growing as a scary story for teenagers spending too much time on the couch. However, being too close to the TV screen will not cause eyesight damage or give you square eyes. No studies are yet forthcoming for the potential damage Keeping Up with the Kardashians has on our souls.

16. Gum Takes Seven Years To Digest

Contrary to what most mothers have told their children for decades, it does not take seven years to digest chewing gum. Duke University gastroenterologist Nancy McGreal, MD, explains that gum will eventually exit the body like all other waste matter- our bodies cannot absorb it, and it will be gone within two hours. Swallowing copious amounts of gum might block an intestine, which would be a somewhat Darwinian act.

17. Brown Sugar Is Healthier Than White

The only real difference between brown and white sugar is the color, and white sugar has been refined to remove the brown residue. The syrupy molasses gives brown sugar its distinct color, texture, and rich flavor. While molasses may contain traces of magnesium and potassium, there is not enough for any health benefit.

18. Neanderthals Were Wiped Out

Paleontologists and geologists established long ago that Homo Sapiens eventually usurped their Eurasian rivals, mostly in wide-scale destruction. However, scientists more recently believe there was a long fraternization period in which much interbreeding happened. One result is that some modern human DNA may contain up to 4% Neanderthal genes.

19. We Eventually Remember Alcoholic Blackouts

The Hangover is a comedy about a group of people using their memories to find their best friend in Las Vegas after an epic bender. However, in real life, it is impossible to remember what happened when we've blacked out because our brain disconnects its memory function when alcohol is exceeded. The NIH-based National Library of Medicine found that alcohol has a disruptive effect on the hippocampus, the part of our brain responsible for memory.

20. The Great Wall Is Visible From Space

Most people of a certain age grew up boasting the common knowledge about the Great Wall of China: it is visible from outer space. However, even the most eagle-eyed astronaut would struggle to see China's grand spectacle, considering how narrow it is. Even NASA admits that only with powerful magnification is the ancient border wall between China and Inner Mongolia visible.

21. We Use Ten Percent Brain Power

Even today, you might hear someone comment how we only use 10% of our brain, but when one puts their mind to it, they will realize that it is absurd. Our brain consists of 90% white matter, which is not used for anything but to protect the gray matter neurons responsible for thinking. The white matter was never in play, so we use every last piece of the gray matter we have for daily function.

22. Blood Is Blue Inside Your Veins

Many myths surround the human body, though none are as weird as the blue-blood theory. For unknown reasons, people believe that the blood in our veins is blue, only turning red once exposed to oxygen. 

23. Water Conducts Electricity

If someone were to find a 100% pure water pool, they could theoretically swim in a thunderstorm. If anything, they would be protected by pure water, which acts as a powerful insulator. Electricity needs dissolved chemicals like salts and other naturally occurring ions in the water to be conducted, says the United States Geological Survey. 

24. Alcohol Kills Brain Cells

Another myth that might stem from concerned parents is that excessive drinking kills brain cells, though this is untrue. Studies show that neurons can be repaired following recovery and abstinence, though alcohol does severely damage neural connections when consumed in repeatedly high volumes.

25. Caffeine Dehydrates You

In good news for coffee drinkers, there seems to be no connection between high caffeine intake and increased dehydration. Of course, coffee is a diuretic, which causes drinkers to visit the restroom more often. However, coffee and tea can be as effective as water for hydration, argues the Mayo Clinic. Increased caffeine consumption can cause other side effects, so it might be unwise to hydrate solely with coffee.

26.  Swallowed Watermelon Seeds Will Grow in Your Belly

Now, with seedless watermelons available, this might not be a worry for kids, but many of us were told that watermelon plants would grow in our stomachs if we swallowed watermelon seeds.  The Rugrats episode, “Aunt Miriam/The Inside Story,” helped support that lie when Chuckie swallows a watermelon seed and his friends shrink themselves to get it out.  According to Prevention, it's a total myth that's funny to look back on that eating watermelon seeds will cause one of the fruits to grow inside your belly.