Ever wondered why yawning seems to be an addictive act? Well now we know why...
There's something about a good yawn that is just so unapologetically satisfying - and more so when someone else hears it and chimes in with their own public display of sleepiness, thus sparking off a conversation about how knackered everyone is.
And now there's a reason for all this: science says contagious yawning is a combination of how empathetic we are, as well as how our brain responds to stimuli.
Researchers from Pisa University in Italy studied sleepy people for five years and discovered that yawning is triggered by social and gender factors such as how well we know each other, and whether we're surrounded by other men and women.
They found that yawning is often a response to someone else doing the same thing, which demonstrates our ability to empathise (which means that the way you yawn could say a lot about you as a person). In fact, the phenomena is more common amongst women than men.
Although men and women yawn spontaneously at the same rate, women are more likely to 'return' someone's yawn because they're better at picking up on how others are doing.
Experts secretly studied people in hundreds of different social situations and concluded that women unconsciously mimic the emotional state of others through yawning and facial expressions, and if participants returned someone else's yawn within three minutes, that showed they were particularly tuned in to the thoughts and feelings of others. To be fair, we'd go as far as to say that you should consider yawning a compliment since it suggests people are paying more attention to you.
The rates of contagion were also lower between acquaintances than between friends and family members.
Explaining the results, the study authors said the behaviour was also displayed in animals that live in extreme proximity with one another such as such as chimps, dogs and wolves, and added: 'These results not only confirm that yawn contagion is sensitive to social closeness, but also that the phenomenon is affected by the same gender bias affecting empathy.'
So basically, if you're tired, female and with your mates, one yawn is more likely to set you all off than if you're a bloke at work.
However the urge to follow suit isn't all to do with your emotions, as it turns out biology also plays a big role. A recent University of Nottingham study made 36 people watch other people yawning and tracked their brain activity as they resisted the temptation.
They found that a part of your brain called the primary motor cortex went haywire and, after stimulating it in their subject’s brains, it actually caused them to yawn even more.
Professor Stephen Jackson who led the study told Medical News Today, ‘There are many theories for why we yawn (e.g., lack of oxygen, to cool the brain, because we are tired, etc., etc.) but the evidence for these is lacking. The popular theory for contagious yawning is that it is linked with empathy for others, mimicry, and social bonding...I still think that much more research is required to understand the function and biology of yawning.’