Just what is it about someone yawning that causes everyone around them to also yawn?
It’s just weird isn’t it, and it doesn’t matter whether you see someone yawn, or just hear someone yawn, you feel the need to follow suit and join in with yawns of your own.
The most amazing thing in my opinion is that you can be on the phone with someone who is on the other side of the world, and given just the merest hint that they are yawning, off you go with your own succession of yawns.
So why do we do this? There seems to be no obvious reason, after all a yawn is just the effect of someone’s body telling them that they need to suck in more oxygen.
When this question was posed to readers of The Guardian in the UK, it triggered a number of responses…
When you yawn, you equalise the pressure in your middle ear. This causes a small, localised pressure change around you, which affects others in the vicinity – and therefore they have to yawn to equalise the pressure in their own middle ears.
Interesting theory, but I don’t really think that this could trigger a yawn in someone who is thousands of miles away.
I heard that infectious yawning was an instinctive survival technique, passing on the yawn from person to person meant that others had to stay alert as one was feeling sleepy.
I rather like this theory, since either the sight or sound of someone yawning could be the trigger that made someone else yawn.
It seems to be that yawning only triggers a response in those who are in empathy with you, and for some reason, autistic children who were shown a video of people yawning, yawned themselves less often than when they were not shown it.
Let’s face it, whether it’s the body telling you that you need to inhale more oxygen, or that you need to exercise your facial muscles, yawning itself is a phenomenon.
The fact remains though, the reason why others helplessly yawn in response, will probably always remain a mystery.