Why Are Yawns Contagious?

As soon as someone starts getting tired, everybody joins in- but why are yawns contagious, and why do we yawn at all?

We usually yawn when we are tired or bored, or simply because somebody else just yawned! These are known things that trigger this reaction, but the purpose of opening our mouth and yawning remains a mystery. For a while researchers believed that yawning indicates a lack of oxygen, but this theory has quickly been disproved.

A study conducted by Andrew and Gordon Gallups for the State University of New York has shown that yawning triggers the exchange of warmth in the brain. Some of the volunteers were given clips to close their nose, which forced them to breathe through their mouth. These volunteers were more likely to start yawning when they saw somebody else doing it, while volunteers who breathed normally through their nose did not yawn. Some volunteers were given a cold item which they were asked to hold on their forehead, and they were also not ‘infected’ by others yawning. Thus, researchers believe it is a result of increased brain temperature and our body tries to ‘cool down’ and enable higher performance. While yawning is not particularly spectacular or graceful, it fills the brain with fresh blood and oxygen, and is also good for your face muscles.

“It is a widespread assumption that yawning is disrespectful and a sign for boredom.” said Gallups “However, it actually reflects a mechanism that maintains attention.”

Gallups also offered an explanation to the question ‘why are yawns contagious?’. He stated that if one person in a group yawns as a result of decreasing cogitation, the other members of the group may also start to yawn to restore the level of attention.

This statement however is merely an assumption and US researchers are still arguing about this topic. Ronald Baenninger from the Temple University Philadelphia argues that the group may simply be synchronising the mood, so when one member gets tired, everyone else gets tired, too. Again, synchronisation is just a theory, not a fact.

British researchers have a different view on that – a study conducted by the University of Leeds has suggested that contagious yawning may be a sign of empathy. This means that one person acknowledges the mood and state of another, and empathises by yawning back. People were asked to wait in a room with a person who yawned relentlessly (the person was part of the research team, but the volunteers were unaware of that). Afterwards, the volunteers were asked to do a test where their social skills, particularly empathy, were examined.

Those people who were immune to the yawning researcher before were less successful in the test than the volunteers who gave in and yawned as well. Interestingly, chimpanzees have been observed to do exactly the same- when one of them starts yawning, everyone else joins in. It is a common sign for ‘Good Night’ among the animal world. This does not only hint towards our similarities, but may also indicate that chimpanzees have a sense of empathy.

So, why are yawns contagious? The truth is that there are many assumptions, but no conclusions. All you need to know is that if you show your friend a 3-hour long home video and he yawns, he is not being disrespectful.  At least he is trying to pay attention and increase his brain performance to dedicate more energy into your boring video. Similarly, if all your other guests then join in and you sit among a group of eager yawners, you should be filled with joy to have such empathetic friends!