There’s a classic joke where someone declares an expertise on a specific topic by claiming that they know the area as well as they know their own body. Then there’s a pause where they discover a marking on their hand that they’ve never seen before and everyone’s confidence is slightly shaken.
We live in our bodies for our entire lives, and it’s shocking how little we know about them, all while we gather expertise on other topics that don’t impact us nearly as intimately such as the minutia of everything Kardashian, complex physics, crime novels, or geography of northern Alaska.
In addition to our lack of biological acumen there are many myths, old wives tales, and common misconceptions that we’re constantly told about the human body as if it is truth. Here’s the thing: we’re wrong, a lot. Many things we’ve been told since we were knee high to a grasshopper, and that we’ll probably tell our own kids, is complete and utter garbage. So many things you thought you knew about this vessel you live in are straight up wrong. Here are 15 common misconceptions about the human body, so get prepared for your mind to be blown (note that’s not a real thing, it’s just an expression).
15 Thin People Have Fast Metabolisms
It’s a natural assumption that a thin person has their slight frame thanks to a fast acting metabolism. This is not true. Thinner people usually have slower resting metabolic rates, and this is because there is a lot less of them to burn while at rest. This is one of the reasons why the addition of muscle plays such a big role in contributing to a speedy metabolism. When you compare two people of the exact same weight, the person who has more muscle mass as a part of their body will usually be the person with the faster metabolism. This is why your personal trainer keeps on integrating strength training into your exercise routine, so the next time you’re offered an opportunity to pick up those dumb bells, just do it!
14 Your Fingerprints Are Super Unique
I distinctly remember a school trip to the police station as a child where we were all fingerprinted and our records were kept just in case we should ever go missing, which in retrospect is a pretty dark moment from a first graders' field trip. Just the same, we’re taught in science class, and when we watch old reruns of CSI, about what unique snowflakes our fingerprints are. Turns out they’re not quite as distinct as we’ve been led to believe. Because of factors including human error, partial prints, and false positive results the usage of fingerprinting identification isn’t nearly as reliable as advertised. Another issue is that although no two fingerprints are identical, neither are two impressions from the same person even when they are recorded immediately after one another.
13 We Only Use 10 Percent Of Our Brains
Scientific research has only brought us so far into tapping into the true human potential. What if there really was a magic pill that could turn all of us into Mensa level superstars (only without the Flowers For Algernon side effects)? Neurologist Barry Gordon has said that the 10-percent-of-the-human-brain myth is so incorrect that it’s almost laughable. While there are particular moments when we only use around 10 percent of our brain power, like when we are lying down and simply thinking, since the brain is at work all the time we use almost every part of it. Gordon added that even though the brain makes up for only three percent of a human’s body weight, it uses somewhere around 20 percent of the body’s energy.
12 Men Think About Doing The Deed Every Three Seconds
Men and women are distinctly different from one another; this is why so many copies of Men Are From Mars, Women From Venus were sold in the 1990s. You’ve probably heard a statistic involving men thinking about sex every few seconds. While many men tend to think about sex more often than most women, this statistic is a gross over-exaggeration. Just take a moment to think about it and run some math numbers, that’s over 8,000 times in waking hours. How would anyone get anything done? In fact there’s no credible research to back up this urban legend statistic. Some have stated that this stat comes from research conducted from the Kinsey Institute, but their studies on men and sex don’t match this staggering suggestion. Kinsey research revealed that of the men surveyed, 54 percent said they think about sex several times a day, 43 percent said they thought about it several times a week, whereas only 19 percent of women said they thought about sex daily (or several times daily).
11 Your Fingernails And Hair Will Continue To Grow After You Die
Many people are under the assumption that the undertaker has extra hair and longer nails to contend with thanks to continued growth after death. According to the Dermatology Clinic at UAMS, this doesn’t really happen, however is assumed since a dead person’s hair and fingernails might appear to be longer than they were when they were living. The skin will lose a lot of moisture in death, which is because of dehydration that can cause the skin around soft tissues to shrink and pull back creating an optical illusion of growth observed by the living. So technically if you measured someone’s hair and nails from root to tip after they have perished it would be longer, however it really hasn’t grown, and it’s simply the shrinkage of soft tissue.
10 The Ability To Roll Your Tongue Is Genetic
Some people have the ability to roll their tongues, whereas others do not. This is generally seen to be a family trait, with people believing that if their mom or dad can roll their tongue that at least one of their children will also be able to. This belief is so common that biology teachers have used this example for years to showcase basic principles of genetics, when in fact several studies have proven that there is no real genetic correlation. Overall somewhere between 65 to 81 percent of people have the ability to roll their tongues, and children can often learn to roll their tongues when they’re older, even if they can’t do it when they are little. Studies with identical twins showed a different ability in several twins about whether or not they could roll their tongues, disproving the strongly believed genetic connection.
9 There Are Flavour “Zones” On Your Tongue
You might remember looking at a tongue map in science class, a diagram showcasing different segments of the tongue that was divided to show different areas for taste receptors. The picture displayed sweet in the front, salty and sour on the sides of the tongue, and bitter at the very back. Guess what? That diagram is wrong, and was disproven by chemosensory scientists a long time ago. The famous, but incorrect map was based on a paper from 1901 by a German scientist named David P. Hänig who wanted to measure the specific thresholds for perception of taste by dripping different flavours on the tongue. He is correct that the tip and the edges of the tongue are more sensitive to tastes thanks to our taste buds, and different sections of the tongue have a lower ability to perceive particular tastes, but these differences are small. This incorrect portion isn’t the findings from Hänig’s results, it is how he chose to display them, in more of an artistic interpretation instead of an accurate scientific representation.
8 Intimate Relations Before An Athletic Event Will Impact Your Performance
Some believe that a romp between the sheets before a major athletic performance will drain your energy. It has been reported that Muhammad Ali wouldn’t engage in bedroom activities for the six weeks leading up to a fight. Scientists confirm that this athletic superstition just isn’t true. Some have even suggested that pre-competition sex will raise an athlete’s testosterone and possibly even improve their game. There is little information available on what psychological impact engaging in such activities would have on a person’s competitive mindset, however. There is a common misconception that those participating in “power sports” like boxing or football abstain from relations leading up to competition since some think that the act of ejaculation can draw the testosterone (and with it much needed aggression) from the body. This simply is not true.
7 Humans Have Five Senses
We learn about and focus on our five main senses, and popular culture reinforces this with films like The Sixth Sense that emphasize our five normal abilities. Truthfully there are at least nine different senses that humans possess, and a lot of researchers believe the number of senses we possess are more in the range of about 21. The senses that we possess include: sight (which is actually two senses, one for colour and one for brightness), taste, touch, pressure, itch, thermoception (our sense of hot and cold), sound, smell, proprioception (the ability to know where your body parts are in relation to your other body parts), tension sensors, nociception (pain sensors), equilibrioception (balance related), stretch receptors, chemoreceptors (the area of the brain that detects blood related hormones and drugs), thirst, hunger, detection of magnetic fields, and time.
6 Most Body Heat Is Lost Through Your Head
The next time you think to put on a hat to keep you warm instead of opting for bundling up your hands, arms, torso, neck and legs, think again. We’ve all heard about how most of the body’s heat is lost through the head, only this just isn’t true, even though at one point even the United States Army Field Manual once claimed that 40 to 45 percent of body heat was lost through the head. According to the British Medical Journal this claim is malarkey. This myth was likely started in the 1950s when a number of military researchers had test subjects exposed to very cold conditions. Because their bodies were properly attired, yet their heads were exposed and they were found to have lost the most heat from their heads. More recent studies from 2008 showed that a person loses seven to ten percent of body heat through their head, proportionate to the total body surface area exposed.
5 You Should Never Wake A Sleepwalker
Urban legends state that you should never wake a sleepwalker for fear of giving them a heart attack or sending them into shock, this is simply not true. Waking up someone who is sleepwalking has never been connected with harm, because sleepwalking occurs during a period of deep sleep known as stage three rapid eye movement (or REM) sleep. Forcing them out of this very deep sleep can cause confusion, startle them, and aggravate them. Because they may be confused after being jolted awake, they may not recognize you and lash out at you – so the real danger here is to the person trying to wake them up. Many sleep experts have suggested that the best solution, instead of forcing them awake, is to simply lead them back to their bed, or another safe place to rest until they wake up naturally, without a shake and a yell.
4 Healthy Teeth Are White
Toothpaste commercials have everyone convinced that a white smile is the healthiest one around. The truth is, we’re just being sold a product for what is considered more attractive, not what is healthier for our overall dental well-being. The healthiest teeth are natural ones, and often a few shades darker than what we might think. Tooth enamel is usually a blueish white shade, with a slightly yellow dentine beneath it contributing to the overall colour. When this shines through the colour of a person’s teeth look either a light grey or light yellow. Really dark teeth can be attributed to heavy smoking or even rarer some metabolic disorders. These dark teeth can be lightened with some bleach, but that won’t make them healthier, it will simply enhance their overall appearance.
3 When You Shave Your Hair It Will Grow Back Thicker & Darker
When someone wants to shave for the first time, whether it’s their legs or their face, they’ve likely been told to hold off, or wax instead since the hair will grow back thicker and darker. While shaving may make the hair appear different, nothing about it has really changed. Instead, the act of shaving gives the hair a coarse or blunt “stubbly” tip. If someone notices a dramatic increase in body hair that is not related to the changes surrounding puberty they may want to talk to their family doctor about potential medical or hormonal causes, as well as some options for hair removal. Another factor at play here is that hair that has just sprung through the skin may look darker simply because it has not yet been lightened by the sun.
2 Sitting Too Close To The TV Is Bad For Your Eyes
Since TVs were invented parents have been yelling at their children for sitting too close to the television set, insisting that it is bad for their eyes. There is no real evidence that sitting directly in front of a TV set can actually cause damage to someone’s sight. The American Academy of Ophthalmology (AAO) says that children are better able to focus up close to an object without eyestrain than adults are, which means that sometimes they get into the habit of sitting very close to a television or computer screen, or even holding a book they’re reading very close to their eyes. This myth probably started because someone sitting too close to a TV or not being able to see from a distance is correlated with nearsightedness, so it could be a major warning sign that junior needs a pair of glasses, however the need for spectacles has absolutely nothing to do with TV.
1 Flat Feet Are More Likely To Get Injured
If there is no dramatic arch in your foot, you may have been told that you have flat feet. Back in World War II, thousands of potential soldiers were turned down for service because they had this “injury prone” affliction. A study of 300 soldiers in the 1980s revealed that the opposite was true, and those who suffered from flat feet were less likely to suffer an injury like a strain or fracture than their high arched counterparts. This means that many people may have literally dodged a bullet thanks to a common misconception about feet. Today many sneaker companies work to give athletes a similar foot support to what is present naturally for flat footed people. It’s likely that this hack will slow down the evolution of natural selection where more and more humans will be flat footed.