7 Surprising Facts About the Chin

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iStock

The human body is an amazing thing. For each one of us, it’s the most intimate object we know. And yet most of us don’t know enough about it: its features, functions, quirks, and mysteries. Our series The Body explores human anatomy, part by part. Think of it as a mini digital encyclopedia with a dose of wow.

The humble chin, that bony protrusion at the bottom of your face, is a mysterious little body part that is a surprising source of controversy among researchers. Though popular culture derives great meaning out of how "strong" or "weak" chins are, very little science backs that up. Here, however, are seven actually scientific facts, which Mental Floss learned from experts, about the chin.

1. RESEARCHERS DISAGREE ABOUT THE PURPOSE OF A CHIN.

The most interesting thing about the chin, according to Faisal Tawwab, a family practice doctor with Multicare Physicians in Orlando, Florida, is that there is no precise answer as to why we even have one. "Prevailing theories include assistance with speech, to protect the jaw from chewing, as a way to measure attractiveness when seeking a partner, or a combination of all three," he tells Mental Floss. "Research to find the true purpose of the chin is ongoing. There are critiques around all of the current prevailing theories."

2. IT MIGHT HELP THE JAW STRESS LESS.

The chin may have evolved to protect the jaw from the unique stresses of shaping our mouths to form language, according to a 2007 study in the journal Medical Hypotheses. Your chin may help bear some of the muscle load of chewing and speaking (a valid reason to want a strong one).

3. THE CHIN IS CRITICAL TO CHEWING.

"The most important function of the chin is mastication [chewing] and lip continence," Francesco Gargano, a board certified plastic surgeon with The Plastic Surgery Center in New Jersey, tells Mental Floss. "Several muscles insert into the chin and are part of the occlusal plane," the space between your teeth when the mouth is closed. Research supports this theory, suggesting that the chin "helps buttress the jaw against certain mechanical stresses," including chewing, which produces a great deal of force.

4. CHINS MAY HAVE HELPED OUR ANCESTORS CHOOSE A MATE.

A more recent theory is that our chins helped us choose mates. "Males tend to have longer chins with a square appearance and flat base. Females tend to have narrower and rounder chins," says Gargano. A 2010 study in the American Journal of Physical Anthropology argues that there would be no difference in chin shape if it weren't related to sexual attraction because there's no functional difference; males and females ostensibly eat and talk the same way. Not everyone agrees. (See #7.)  

5. WE'RE THE ONLY ANIMALS WITH CHINS. 

While humans may share some things in common with animals, chins are not one of them. "Elephants are the only other creature with a body part similar to the chin," Tawwab says. But the elephant's "chin" is actually caused by a lack of lower teeth and a big lower lip. It's not a bony protrusion, which is a real chin—and a feature that's ours alone. The human chin is considered a cladistic apomorphy, Tawwab says: a feature or body part not found in the earliest forms of a clade (group of organisms sharing a common ancestor). In short, it's evidence of our species's evolution—and one of our defining physical characteristics.

6. DOES HAVING A CHIN CLEFT IMPROVE YOUR DATING PROSPECTS? 

"Historically, numerous cultures have assigned meanings to being born with a cleft chin, usually pertaining to luckiness in love," Tawwab says. The reality is much more mundane. "The current theory suggests that a cleft chin is actually caused by an incomplete fusion of the jaw bones before birth." There are several types of clefts, as well: vertical furrows, Y-shaped furrows, and round dimples. 

7. A CHIN MAY SIMPLY BE WHERE EVOLUTION STOPPED.

A chin may not have anything to do with withstanding pressure or attracting a mate, according to Nathan Holton, an anthropologist at the University of Iowa. His research suggests that the Homo genus (including humans, Neanderthals, and other relatives) simply evolved smaller faces—and Homo sapiens most of all. The lower jaw is the last part of the face to stop growing, which causes it to be more prominent as compared to other parts of the face. The prominent chin "is a secondary consequence of faces getting smaller," Holton writes.

10 Products for a Better Night's Sleep

Amazon/Comfort Spaces
Amazon/Comfort Spaces

Getting a full eight hours of sleep can be tough these days. If you’re having trouble catching enough Zzzs, consider giving these highly rated and recommended products a try.

1. Everlasting Comfort Pure Memory Foam Knee Pillow; $25

Everlasting Comfort Knee Pillow
Everlasting Comfort/Amazon

For side sleepers, keeping the spine, hips, and legs aligned is key to a good night’s rest—and a pain-free morning after. Everlasting Comfort’s memory foam knee pillow is ergonomically designed to fit between the knees or thighs to ensure proper alignment. One simple but game-changing feature is the removable strap, which you can fasten around one leg; this keeps the pillow in place even as you roll at night, meaning you don’t have to wake up to adjust it (or pick it up from your floor). Reviewers call the pillow “life-changing” and “the best knee pillow I’ve found.” Plus, it comes with two pairs of ear plugs.

Buy it: Amazon

2. Letsfit White Noise Machine; $21

Letsfit White Noise Machine
Letsfit/Amazon

White noise machines: They’re not just for babies! This Letsfit model—which is rated 4.7 out of five with nearly 3500 reviews—has 14 potential sleep soundtracks, including three white noise tracks, to better block out everything from sirens to birds that chirp enthusiastically at dawn (although there’s also a birds track, if that’s your thing). It also has a timer function and a night light.

Buy it: Amazon

3. ECLIPSE Blackout Curtains; $16

Eclipse Black Out Curtains
Eclipse/Amazon

According to the National Sleep Foundation, too much light in a room when you’re trying to snooze is a recipe for sleep disaster. These understated polyester curtains from ECLIPSE block 99 percent of light and reduce noise—plus, they’ll help you save on energy costs. "Our neighbor leaves their backyard light on all night with what I can only guess is the same kind of bulb they use on a train headlight. It shines across their yard, through ours, straight at our bedroom window," one Amazon reviewer who purchased the curtains in black wrote. "These drapes block the light completely."

Buy it: Amazon

4. JALL Wake Up Light Sunrise Alarm Clock; $38

JALL Wake Up Light Sunrise Alarm Clock
JALL/Amazon

Being jarred awake by a blaring alarm clock can set the wrong mood for the rest of your day. Wake up in a more pleasant way with this clock, which gradually lights up between 10 percent and 100 percent in the 30 minutes before your alarm. You can choose between seven different colors and several natural sounds as well as a regular alarm beep, but why would you ever use that? “Since getting this clock my sleep has been much better,” one reviewer reported. “I wake up not feeling tired but refreshed.”

Buy it: Amazon

5. Philips SmartSleep Wake-Up Light; $200

Philips SmartSleep Wake-Up Light
Philips/Amazon

If you’re looking for an alarm clock with even more features, Philips’s SmartSleep Wake-Up Light is smartphone-enabled and equipped with an AmbiTrack sensor, which tracks things like bedroom temperature, humidity, and light levels, then gives recommendations for how you can get a better night’s rest.

Buy it: Amazon

6. Slumber Cloud Stratus Sheet Set; $159

Stratus sheets from Slumber Cloud.
Slumber Cloud

Being too hot or too cold can kill a good night’s sleep. The Good Housekeeping Institute rated these sheets—which are made with Outlast fibers engineered by NASA—as 2020’s best temperature-regulating sheets.

Buy it: SlumberCloud

7. Comfort Space Coolmax Sheet Set; $29-$40

Comfort Spaces Coolmax Sheets
Comfort Spaces/Amazon

If $159 sheets are out of your price range, the GHI recommends these sheets from Comfort Spaces, which are made with moisture-wicking Coolmax microfiber. Depending on the size you need, they range in price from $29 to $40.

Buy it: Amazon

8. Coop Home Goods Eden Memory Foam Pillow; $80

Coop Eden Pillow
Coop Home Goods/Amazon

This pillow—which has a 4.5-star rating on Amazon—is filled with memory foam scraps and microfiber, and comes with an extra half-pound of fill so you can add, or subtract, the amount in the pillow for ultimate comfort. As a bonus, the pillows are hypoallergenic, mite-resistant, and washable.

Buy it: Amazon

9. Baloo Weighted Blanket; $149-$169

Baloo Weighted Blanket
Baloo/Amazon

Though the science is still out on weighted blankets, some people swear by them. Wirecutter named this Baloo blanket the best, not in small part because, unlike many weighted blankets, it’s machine-washable and -dryable. It’s currently available in 12-pound ($149) twin size and 20-pound ($169) queen size. It’s rated 4.7 out of five stars on Amazon, with one reviewer reporting that “when it's spread out over you it just feels like a comfy, snuggly hug for your whole body … I've found it super relaxing for falling asleep the last few nights, and it looks nice on the end of the bed, too.” 

Buy it: Amazon 

10. Philips Smartsleep Snoring Relief Band; $200

Philips SmartSleep Snoring Relief Band
Philips/Amazon

Few things can disturb your slumber—and that of the ones you love—like loudly sawing logs. Philips’s Smartsleep Snoring Relief Band is designed for people who snore when they’re sleeping on their backs, and according to the company, 86 percent of people who used the band reported reduced snoring after a month. The device wraps around the torso and is equipped with a sensor that delivers vibrations if it detects you moving to sleep on your back; those vibrations stop when you roll onto your side. The next day, you can see how many hours you spent in bed, how many of those hours you spent on your back, and your response rate to the vibrations. The sensor has an algorithm that notes your response rate and tweaks the intensity of vibrations based on that. “This device works exactly as advertised,” one Amazon reviewer wrote. “I’d say it’s perfect.”

Buy it: Amazon

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30 Pungent Facts About Farts

This man is clearly not trying to hide the fact he just passed gas.
This man is clearly not trying to hide the fact he just passed gas.
BrilliantEye/iStock via Getty Images

Whether you openly admit it or desperately try to hide it, it’s an undeniable fact that every living and breathing human being farts. And while passing what you thought was going to be silent gas only to be wrong in certain situations can definitely be embarrassing, there’s something undeniably humorous about flatulence—no matter your age.

If you do love a good fart joke, you’re in good company. The very first recorded joke, which was written by the Sumerians and dates all the way back to 1900 BCE, was about—you guessed it—breaking wind. And some of the world's great thinkers, from William Shakespeare to J.D. Salinger, have slipped a fart joke (or 10) into their work.

In this episode of The List Show, we're sniffing out 30 fascinating facts about farts—from why humans expel gas to how often the average adult squeezes the cheese. You can watch the full episode below.

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