35 Weird Facts About The Human Body And Brain
Let’s face it: Human bodies are weird. They’re also an endless source of fascination for kids, given the plethora of strange and gross stuff going on inside of our bodies at any given moment. Should your kids know everything there is about their boogers, brains, and bodies? Of course they should. Give the strange facts about bodies to them straight. Our bodies are weird, sure, but they’re part of our world and every fact about it, no matter how gross, is a lesson in celebrating both science and ourselves. It may get weird, but don’t hesitate to share — think of it as a celebration of our wild and wonderful human bodies.
Here are 35 strange and weird facts about the human body.
1. You’re Taller In The Morning
You may not be at your best first thing in the morning, but you are at your tallest. While we stretch out to sleep at night, gravity gradually compresses cartilage in our spines and knees throughout the day, bringing us down. Interestingly, when astronauts come back from space, they are a few inches taller because of the lack of gravity they were exposed to, before gradually returning to their own size.
At 5’ 7”, that explains why Jeff Bezos went to space, and why you should measure your kids for their latest height notch on the wall before breakfast.
2. You Can Pinch A Weenus As Hard As You Want
Forget occupying your kid with a book or screen. There is no better juvenile distraction than playing with your weenus. The extra skin on your elbow, known scientifically as olecranal skin or colloquially at the weenus, is basically nature’s Silly Puddy because there are fewer sensory neurons located there. That means you can keep kneading it all day long, and as hard as you want. That’s not to say that you can’t injure your elbow in other ways like playing tennis or overdoing it at the gym, but treating your extra skin like a stress ball is fair game.
3. Your Brain Is Fat
Your brain is the fattiest organ in your body, composed of approximately 60% fat. And that is exactly how voluptuous it should be, because the brain needs essential fatty acids in order to perform adequately, and imbalances could increase the risk of developing neurological diseases such as ADHD, Alzheimer’s, schizophrenia, and depression. So instead of worrying about belly fat, praise your fat operating system upstairs for keeping your body in check. Perhaps rappers should’ve been praising your juicy cerebrum all along.
— Ariela Basson/Fatherly; Getty Images
4. But It Shrinks When You Become A Parent
Scientists believe that having a baby changes the brain of new mothers, resulting in less gray matter in areas of the brain involved with responding to social signals and general processing. However, new research recently revealed that dads experience similar shrinkage in their brains in regions related to executive functioning and visual processing.
In both experiments, the researchers concluded that all of these neurological changes are normal and likely a biological response to enhance different parenting roles. So bring on that baby brain.
5. Your Brain Starts Slowing Down At 24
If you were worried you peaked in high school, add about a decade to that and scientists would agree. A study of 3,305 people ages 16 to 44 first detected declines in cognitive speed at age 24, which dropped by about 15% for every 15 years after that. If you’re closing in on 40, these numbers may take a bit longer to crunch, but it adds up to your quickest days being behind you.
6. You Lose Bones As You Grow
Babies are born with about 300 bones in their bodies, but as we grow up and mature, this number gets whittled down to about 206 bones. So what the hell happened to turn your skeleton into a bone vortex? Here’s the thing. Infants are made up of many smaller bones and more cartilage so they can bend and adjust to the womb and birth canal. But as they grow, these bones fuse together, decreasing the number of bones overall. So baby bones aren’t up and disappearing; they’re just teaming up.
7. Your Pinky Is The Strongest Finger
Despite the notion that the pinky contributes half of our grip strength, it’s closer to a third, which is still pretty impressive for the tiny fifth finger. Research shows that the pinky and ring finger account for about 54% of grip strength, but of the powerhouse pair, the pinky accounts for 33% of that strength. So it’s still the strongest of all five fingers overall, and arguably worthy of every ring put on it.
8. Your Ring Finger Is Giving Away Intel
Your ring finger can tell people whether or not you’re married — but even before you settle down, that finger holds other clues. In 1998, evolutionary biologist John Manning discovered that longer ring fingers indicate higher levels of prenatal testosterone in the womb. Since then, his findings have been duplicated across a number of studies that confirm that people with longer ring fingers perform better at sports. Likewise, there is some evidence that men with longer ring fingers display more physical aggression. Perhaps that’s why boxing gloves look like mittens — to make it less obvious who the champ will be.
9. A Quarter Of Your Bones Are In Your Feet
For only making up a small portion of your body, your feet contain 26 bones per foot, 52 total, accounting for about a quarter of the bones in your entire skeletal structure. Between the14 phalanges, 7 tarsal bones, 5 metatarsals, and 2 sesamoids, on top of over another 33 joints and hundreds of ligaments, your feet are far more than a few little piggies who went to the market. They are 52 out of 206 bones all together, or one fourth of your bones. They should be respected as such — even if they are ticklish.
— Ariela Basson/Fatherly; Getty Images
10. The Strongest Muscle In The Human Body Is The Jaw
Forget working out your lats, biceps, or glutes. You were already exercising the strongest muscle in the human body when you were housing a burger and talking trash with your buddies, because the strongest muscle in the human body is the masseter, aka the jaw. A healthy jaw is capable of closing a set of teeth with a force of up to 200 pounds, according to the Library of Congress. If you were looking for an excuse to refer to snacking as “strength training,” now you have it.
11. Teeth Are Almost As Hard As Opal
Although your jaw may be the strongest muscle, the hardest substance in the human body is a neighbor: your teeth. Specifically, tooth enamel — one of four different types of tissue found in teeth — is composed of minerals that are so densely packed that they’re technically the hardest part of the body. To put it in perspective, the Mohs Hardness Scale taps out with diamonds at a hardness of 10. Teeth come in at a hardness of 5, compared to 3.5 for copper pennies and 5.5 for the gem mineral opal. Among many other reasons, that is why you should never propose with a ring made out of teeth (but some men do).
12. Sperm Can Survive A Lot Longer Than You Think
Although there is reason to worry about the sperm health of men globally, on an individual level these swimmers are pretty resilient. Provided that they’re in a woman’s reproductive tract and not a hot tub, sperm can survive for up to five days after ejaculation. This explains why people can become pregnant if they have sex several days before ovulation, and why the famous sperm race scene in the 1989 comedy “Look Who’s Talking” was more of a marathon than a sprint.
13. There’s a Difference Between a Grower And A Shower
It’s not just an expression about boners. One study found that some penises experience notable size changes over four centimeters — the minimal cutoff for being considered a “grower” — whereas some guys experience very little size changes when aroused, regardless of what they were working with to begin with. They also found that “growers” tended to be younger men, so it’s possible to age into being a “shower.”
14. Vaginas Change Size Too
Dudes aren’t the only ones experiencing fluctuating genitals, and given the logistics of sexual intercourse, this makes some sense. Research shows that vaginal depth ranges from 2.7 to 3.1 inches. But in a state of sexual arousal, this can increase to a range of 4.3 to 4.7 inches. So while men are growers and showers, ladies appear to have more depth.
15. Vaginas Are Like Wine — They’re Acidic
A pH value is meant to measure how acidic something is, which is important for anyone with a vagina because that score could leave you susceptible to a number of uncomfortable infections. However, there’s one relatively easy way to remember the healthy pH level for a vagina, which is around 4.5 — it’s a similar pH range as wine. Of course, sharing this information will probably make any wine tasting or prenatal appointment very weird. But that doesn’t mean you’re wrong.
— Ariela Basson/Fatherly; Getty Images
16. The Skin On Your Genitals Is Darker
Skin tone can vary all over your body, but you might have noticed that your skin downstairs is distinctly darker. Rest assured, this is entirely normal and a result of the amount of melanin produced in that area. Skin is composed of cells known as melanocytes, and sex hormones like testosterone and estrogen determine how much melanin is released in a particular area, which determines skin tone. The skin around the nipples, anus, and genitals is more sensitive to these sex hormones, so it’s darker than the rest of the body. The level of contrast increases during puberty and pregnancy, when sex hormones spike.
17. Stomach Acid Can Melt Metal
If you’ve ever had heartburn so bad that it felt like your burps could melt faces, you might be onto something. The digestive juices in the gut contain hydrochloric acid, which can dissolve certain metals like zinc and falls just below battery acid on the pH scale. One study found that gastric acid could even partially break down razor blades, but not copper, so it’s a mixed bag. But you may want to pack Tums just in case.
18. Your Intestines Are Always Moving
If you’ve ever wondered why your stomach makes noises, the grumbling is likely a result of a process called peristalsis, an automatic and continuous wavy movement of the muscles that line your gastrointestinal tract, which aids in digestion. (Or when the vomiting reflex is triggered, and muscles move the food backwards, up the esophagus and out the mouth, it’s known as reverse-peristalsis.) So if your gut is making noise, it’s also probably doing the wave as well.
19. You Literally Have To Fart
Much to the delight of little kids everywhere, farts and burps are an entirely natural, unavoidable part of being human. The way it works is that when people eat, our small intestines don’t fully digest all the carbohydrates. What’s left over is broken down by bacteria in the large intestine and converted into gas. From there, the gas is expelled in the form of a fart or burp, making a person passes gas about 12 to 25 times a day on average. But no one is going to die from holding in flatulence. Holding in farts might result in stomach discomfort, or even bad breath. Beyond that, being polite at the dinner table won’t cause any lasting medical issues.
20. Some People Can Give Themselves Goosebumps
Goosebumps are caused by tiny arrector pili muscles that contract and raise the hairs on your skin when you’re cold, being tickled, or experiencing other types of sensory stimuli. This is known as piloerection, which is a fun enough word in itself. But even creepier, there are some, albeit a small amount of people, who can contact these muscles consciously and can give themselves goosebumps on command, like a deranged party trick. Maybe that’s what R.L. Stine was writing about all this time.
21. Body Hair Is Nature’s Lint Trap
Deep in the bowels of the internet, you might encounter men asking: Why do I have more lint in my belly button than my romantic partner? In their defense, the answer isn’t because they’re grosser, but because men are usually hairier. Belly button lint is composed mostly of dead skin cells and clothing fibers, and scientists believe that body hair actually pulls lint in from your clothing when you inhale and exhale. This is why women, men with less body hair, and anyone with an outie belly button are all less vulnerable to lint in their belly buttons. If you’re having trouble with lint and don’t want to part with your precious body hair, now you have a very specific excuse to go shirtless.
22. You Produce Up To Four Pints Of Spit Per Day
Saliva serves an important function of neutralizing harmful stomach acid, killing germs, and helping prevent tooth decay, gum disease, and bad breath, so it’s a good thing that you make a lot of it. Although the commonly circulated figure is about two full swimming pools of spit in a lifetime, or 25,000 quarts, this doesn’t appear to be verified in any scientific way. However, Live Science estimates that the average person produces about two to four pints of spit per day. Cheers to the foam on your beer for not being that.
23. Your Nostrils Are A Tag Team
The difference between nostrils may seem more pronounced when you have a cold, but it’s totally normal for one of your nostrils to be working harder than the other, and for them to trade off throughout the day. Referred to as the “nasal cycle,” one nostril does about 75% of the breathing at any given time, and this switches off every two hours or so. Since the nasal cycle is thought to be controlled by the autonomic nervous system, leaning into this pattern by intentionally alternating nostrils with each breath can have calming effects. It might feel silly at first, but that just means your kid may actually try it when you need them to chill out.
24. The Human Body Technically Glows In The Dark
Similar to glow worms and fireflies, humans are bioluminescent, meaning we emit light. This is mostly as a result of a metabolic reaction in which free radicals are produced through cell respiration, causing us to glow. The big difference between humans and fireflies is that the light we produce is about 1,000 times weaker than the human eye can detect. However, at least one study has captured the glow though ultrasensitive cameras. It’s worth noting that researchers found that the light was at its highest in the afternoon and was the brightest in the cheek, forehead, and neck areas — in case they ever make a blacklight for that.
— Ariela Basson/Fatherly; Getty Images
25. Your Fingernails Grow Three Times Faster Than Your Toenails
The main reason people bite their fingernails more than their toenails may not be because it’s marginally less gross and requires less acrobatics, but because they have more raw material to work with. Studies and dermatologists alike confirm that fingernails grow about three times faster because your hands have more blood pumping through them due to closer proximity to the heart, which facilitates growth. That’s also why your fingernails grow at a slower rate in colder weather — because blood flow is being restricted.
26. Women Blink More Often Than Men
Although blinking doesn’t seem like it should be gendered, women blink about twice as often as men. Specifically, women have been found to blink 19 times a minute compared to 11 times a minute for men. Researchers believe this has to do with the hormone estrogen, which can make the cornea more elastic and change how light travels through the eye, making women more susceptible to blinking. Likewise, as women’s estrogen levels decrease, their rate of blinking also declines. In other words, your spouse may not be batting her eyes flirtatiously, she just has more estrogen than you do.
— Ariela Basson/Fatherly; Getty Images
27. Men Are More Sensitive To Coffee
Sex hormones like estrogen may also be why women appear to be less reactive to caffeine. One study found that men were more responsive to a single dose of 100mg of caffeine in regular coffee than women, whereas women reacted more to decaf coffee. An additional study confirmed that higher levels of estrogen in women were similarly linked with being less affected by caffeine, indicating that estrogen is to blame for this sex difference. Add that to your long list of reasons to never tell a woman she looks tired. It’s not her fault the Starbucks didn’t take.
28. Your Liver Can Regenerate Itself
The liver is the only organ in the human body that can regenerate itself, a phenomenon that’s been recognized since the days of Greek mythology and has since been confirmed by modern science. Although some injuries and diseases can damage the liver beyond repair, the organ has the capacity to regenerate itself even after 90% of it has been removed, according to the National Institutes of Health. That’s why unlike kidney donors who give up one of their two organs, liver donors only have to give up a piece of theirs, which will grow back on its own. Maybe that’s why it’s called the liver, because like Matthew McConaughey in Dazed and Confused, it just keeps on livin’.
— Ariela Basson/Fatherly; Getty Images
29. Pus Is Just White Blood Cells
As disgusting as pus is, it’s an important indicator that your body is working as it should. That’s because the gross, white (and occasionally yellow, green, and brown) substance is a product of white blood cells building up, which is a result of a healthy immune system that responds effectively to infection. There are some exceptions, like after major surgery, when pus is a cause for concern and a reason to contact your doctor. But in the case of smaller injuries, pus is a sign of a good and gross job done, in terms of healing.
30. Your Eyes Can Get Sunburned
Stanford University neuroscientist Andrew Huberman has spoken out about the importance of getting sunlight in your eyes each morning to promote a healthy sleep and wake cycle. However, you might not want to take this premise too far — because eyes can get sunburned. Known as photokeratitis, the symptoms of sunburned eyes include headaches, eye pain and redness, tearing eyes, blurred vision, twitching, and a gritty sensation in the eyes. Luckily, sunglasses can prevent this, and the only side effect is looking super cool. But if you can’t find your shades on a beach day, rest assured that the symptoms of photokeratitis typically resolve themselves after 48 hours without doing any real damage.
31. Twins Smell The Same
If having the same DNA weren’t enough, the weirdest thing about identical twins is that even if they don’t share matching outfits, they still share a scent. Studying the scents of identical twins, Swiss researchers discovered that twins smell 10 times more similar compared to non-related pairs. This was expected, as our body odor is thought to be rooted in genetics. But now you know dogs probably can’t tell twins apart either.
32. Your Temperature Control System Is A Little Gross
Most people love air conditioning in the summer and depend on furnaces in the winter, so we should have more respect for our own natural heating and cooling systems. The only problem is that the temperature controls on the human body happen to involve some of the least attractive aspects of it: sweat and hair. When we’re cold, the muscles around our hair follicles contract, causing hairs to stick out more, which insulates the body by preventing heat from leaving it, When we’re hot, sweat glands release a combination of water, plus a little salt and fat, in a mixture known as sweat, to cool us down. So the next time you want to make fun of your buddy for being sweaty, consider complimenting him on his internal central air.
33. Part Of Your DNA Isn’t Exactly Human
Human beings are 99.9% the same, genetically speaking. As inherently unoriginal as that may be, there is a twist: Not all of your genes are human. Of the approximately 20,000 genes in the human genome, about 8% are made up of ancient viruses, on top of another 40% of repetitive strings of letters that are thought to be viral as well. Scientists suspect that these viral genes can jump throughout the genome and copy themselves, potentially contributing to diseases like multiple sclerosis and amyotrophic lateral sclerosis (ALS). It seems as complicated as it is scary, but the point is that when it comes down to your coding, you’re not that basic after all. You’re barely half human.
34. New Species Of Humans Are Still Being Discovered
As of right now, there are 21 known species of human, and the Homo longi was uncovered as recently as 2018. Scientists have also discovered hybrids of some human species, such as a girl with a Neanderthal mother and Denisovan father known as Denny. In case it’s not clear what species your screaming toddler is, they’re a Homo sapien, allegedly.
35. The Brain Can Survive After Death For Longer Than You Think
Typically, a person is considered legally dead when their heart stops beating. However, science is constantly evolving, and experts are constantly discovering new things about life and death. As pulmonologist and critical care expert Sam Parnia told the New York Academy of Sciences, we used to think a person had a few minutes after their heart stopped before their brain cells died from lack of oxygen and ceased to function, but now we know that’s not true either.
“You have hours, if not days, before the brain and other organs in the body are irreversibly damaged after death,” Parina explained. From there, your brain and cells go through a secondary death process, which is why there are people who’ve been declared dead but came back to life. “So, this accelerated secondary injury process is what we need to combat in medicine now,” he added.
As much as he’s not a fan of the imprecise term “near death experience,” Parina conceded that this phenomenon does occur. And sure, that may be a heavy concept for a kid to grasp, but it could provide comfort to parents that scientists might figure out how to keep the lights on upstairs longer. That way you can regale your great-great-great grandkids with some of the aforementioned facts, which hopefully haven’t changed too much by then.