Turns out there’s another theory as to why we yawn and it’s nothing to do with our brains needing oxygen or being tired.

Yawning. As soon as you read that you probably found a yawn creeping into your mouth and either had to work pretty hard to stifle it or just let your mouth open wide in all its glory.

But why do we do it? Well, it’s been long-debated by scientists with no definitive answer come to rest on, however, a new intriguing theory has since arisen.

What yawning is – scientifically speaking

Yawning ‘is the opening of your airway and mouth to take a long, deep breath of air,’ Cleveland Clinic explains.

It continues: “It’s a complex muscular movement. In seconds, your entire airway fully dilates (expands). And surrounding muscles powerfully stretch or tense, most significantly around your throat (pharynx). Another term for yawning is oscitation.”

The site notes the human function is ‘common but perplexing’ and no theory is certain, however many ‘common triggers’ include ‘tiredness, boredom, waking up and stress’.

“Seeing or hearing other people yawn can also cause you to yawn,” it adds.

However, a new theory has since been proposed as to why we crack open our mouths – and why you’ll probably do so simply while reading about yawns during this article.

Try not yawn throughout this, I dare you (Getty Stock Images)

A new theory

State University of New York at Oneonta’s Andrew Gallup came up with the theory during his undergraduate degree.

He queried whether yawning was, in fact, actually a motion spurred on in a bid to help to cool off the brain.

In the study, Gallup argues the opening of the jaws in such an abrupt way sparks blood flow around the skull which, in turn, helps regulate the brain’s temperature.

As you yawn, you inhale too, which Gallup explains brings air into your system which leads back to the brain, similarly having a cooling effect.

Rather than simply theorizing, Gallup decided to test his prediction out.

People were put to the test in normal conditions and then asked to hold a cold compress to their heads.

The theory argues yawning may be a way of cooling the brain (Getty Stock Images)

Testing the theory

The study reveals: “When participants held a warm pack (460 C) or a pack at room temperature to their forehead while watching people yawn, contagious yawning occurred 41 percent of the time.

“When participants held a cold pack (40 C) to their forehead, contagious yawning dropped to 9 percent.”

The temptation to yawn was prevented further by the participants being asked to breathe through their nose – a reported quicker way to cool the brain compared to mouth breathing.

“There were no yawns in the nasal breathing group. In all other groups, at least 45 percent of viewers yawned at least once. In the strictly oral breathing group (not the nose plug condition), 54 percent of viewers yawned at least once,” the study continues.

Gallup also asked participants to pop a thermometer in their mouths before and after yawning and found participants’ temperatures allegedly rise just before and then drop after.

Is yawning really a sign of you being sleepy? (Getty Stock Images)

The study resolves: “According to our hypothesis, rather than promoting sleep, yawning should antagonize sleep. It has been widely believed that yawning in the presence of others is disrespectful and a sign of boredom (e.g., witness the fact that many people cover their mouths when they yawn).

“However, according to our account yawning more accurately reflects a mechanism that maintains attention. Likewise, when someone yawns in a group setting as evidence for diminished mental processing efficiency, contagious yawning may have evolved to promote the maintenance of vigilance.”

However, University of Bern’s Christian Hess argued: “Gallup’s group has failed to present any convincing experimental evidence to support his theory.”

So, what do you think?

Buying second-hand can be good for the environment and for your bank balance.

And with the likes of Marketplace and Vinted, as well as vintage shops and thrift stores, there’s so much opportunity to grab a one-of-a-kind bargain, that’s sustainable too.

But there are some items you should probably avoid buying in a used condition.

Two experts speaking to Marthastewart.com have revealed which items you should leave firmly at the yard sale – and some of these might surprise you.

Buying secondhand can be good for the environment and your bank balance (Getty Stock Photo)

Pillows

The thought of buying somebody else’s old pillow probably makes you feel a little uneasy, and for good reason.

As well of the risk of bacteria and mould, pillows can also carry lice and bed bugs.

“You don’t know where they’ve been or how they were used,” said interior designer, Alexandra von Gymnich-Scully.

Bedding

Bedding is a no-go too, for very similar reasons.

Although it can be tempting, bedding can harbour all kinds of bacteria, as well as dust mites, bed bugs and some pretty unpleasant odours.

“You just don’t know the backstory of how the bedding was used or where it was used,” added Gymnich-Scully.

If you can, try and buy bedding new or hunt around for cheaper sale items.

Mattresses and upholstered headboards

You’re probably realising by now that anything to do with beds and beddings isn’t a good idea.

“While bed bugs or bodily fluids are probably the primary concerns most people have with a used mattress, my biggest concern is actually support,” said stylist and vintage re-seller, Andi Jenkins.

“Mattresses break down with regular use, and a used mattress typically has sagging, sloping, or dips that can wreak havoc on your quality sleep and body.”

Meanwhile, upholstered headboards can also be a magnet for bacteria, due to a build up of grime from hair products.

Buying a secondhand mattress isn’t a good idea (Getty Stock Photo)

Car seats

Car seats can be super expensive, so it’s very tempting to explore used options.

However, buying a car seat secondhand is a huge no-no.

This because a potential buyer has no idea if the seat has been damaged or if it’s been involved in an accident previously.

If it’s an older model, it may not meet current safety standards, either.

“Many people don’t realize that car seats have an expiration date, so parents need to make sure they understand how many useful years are left prior to purchasing secondhand,” added Jenkins.

Vintage cribs

Similarly, older, vintage cots are not a good option for a baby due to ever-changing safety standards.

Helmets

New helmets should always be purchased over used ones.

While helmets should be replaced periodically, just like car seats it’s impossible to know if they’ve been involved in an incident previously.

A helmet must also fit properly to ensure it is safe, which is especially harder to determine if bought online, or if there’s restrictions over returning.

There are certain items you shouldn’t buy secondhand (Getty Stock Photo)

Appliances

If you can’t test an appliance beforehand, it’s generally not a good idea to buy it secondhand.

Without a guarantee or proof of purchase, it’s hard to establish when the appliance was bought and how long it might have left.

“Appliances already have a short lifespan,” said von Gymnich-Scully.

“You won’t get your money’s worth.”

Rugs

If you are going to buy a secondhand rug, it’s important to pay extra attention to any chew marks from pets, stains or dodgy odors that could be difficult to remove once you get it home.

Gymnich-Scully says it’s best to avoid buying used rugs, with the exception of a vintage Persian style.

Dishes

Vintage dinnerware is hard to resist, but the experts point out that if you want to buy vintage dishes, you should be aware of the risk of lead, which is sometimes found in old dinnerware.

You should pay extra attention to ceramics made prior to the 1970s, when the United States Food and Drug Administration began regulating the use of lead in dishes.

Luxury products

It’s essential that if you’re buying used, luxury products, with a price tag to match, that you can make sure they are authenticated first.

As the colder months begin to set in, more of us are likely to start wrapping up in bed – socks and all.

Wearing socks in bed has long been a topic of debate. While some think it’s impossible to sleep without fluffy socks in the winter, others find the idea uncomfortable.

If you’re one of the folks who likes super toasty feet in bed, then you’re going to want to read on.

People are being urged not to wear dirty socks to bed (Getty Stock)

If the washing basket it full and you’re running low on socks, you might be tempted to wear the same ones in the day and then to bed, but experts are strongly urging that you don’t.

A study by Mattress Next Day looked into the bacteria found on worn socks and discovered presence of a bacteria called Pseudomonas aeruginosa – something cockroaches and their bacteria spread. Ew.

The company polled 1,000 people and 18 percent admitted to wearing socks in bed, with only 30 percent saying they put on a fresh pair at night, House Beautiful reports.

The matter was discussed on the Calm Down With Erin and Charissa podcast, and it’s safe to say that they were pretty grossed out by the news.

You could be carrying bacteria into your bed through your socks (Getty Stock)

They labeled the findings as ‘disgusting’ and questioned why people wear socks in bed in the first place.

Their response then sparked a debate as some people were in favor of sock-wearing in bed, while others weren’t.

Someone asked: “I’m shocked this many people are clueless to life in winter in a cold climate. Who DOESN’T wear socks to bed in winter in northern lattitudes?”

In contrast, another person penned: “Wearing socks to bed seems like the most uncomfortable thing imaginable.”

Echoing similar sentiments, a different person said: “Who the hell wears socks to bed???”

While wearing dirty socks to bed is advised against by experts, clean (ish) socks aren’t actually an issue.

“Wearing socks around the house and then getting into bed is generally not a health concern,” Anna Chacon, MD, a Miami-based board-certified dermatologist told House Beautiful.

“It can provide comfort and warmth. However, if your socks are dirty or sweaty, it’s a good practice to change into clean ones before getting into bed to maintain good hygiene.”

But be warned; even if your socks haven’t actually touched the ground and you’ve been wearing shoes all day, Carlie Gasia, a certified wellness coach at Sleep Advisor, said that ‘your socks can still accumulate dirt and bacteria’ in your shoes – especially if you get sweaty feet.

Gross.