Q: How and why is yawning contagious?

Asked by Aurelia Lange

Yawning may be considered an everyday occurrence but in the eyes of science it is still very much a mystery. There is no clear understanding of why we yawn, and the fact that it appears to be contagious adds further questions to the already puzzling subject. 

Perhaps the most well known and seemingly biological theory is that we yawn to increase the oxygen supply to the brain and body, and that contagious yawning is a social adaption so that groups of humans can maintain the same level of alertness. However through thought and experimentation this theory has been dismantled, with other theories sprouting their heads within different scientific circles. 

An example of such a theories is The Brain Cooling Theory where yawning is seen as a way of inhaling cooler air to maintain an optimum heat in the brain, as the brain is thought to perform better at a certain temperature. There is also a theory that we yearn to stretch our lungs to prepare them for use, however this does not explain why we yawn when tired and before bed as we would not need to prepare our lungs for use during sleep (unless we’re planning a particularly strenuous sleepwalking expedition).

With the purpose of yawning still in dispute, the definitive answer to why yawning is contagious may still be a long way off. Excitingly there have been some interesting results in a recent test, which ties contagious yawning with social behaviour and empathy. Researchers at the University of Connecticut investigated into the susceptibility of young children with and without autism to contagious yawning. The results showed that children with autism were much less susceptible then children without autism, where children with severe cases of autism didn’t react to the yawns of others at all.

‘This lack of early mimicry could also impact feelings of psychological connection and opportunities for social learning. These changes could thus leave children with autism unable to recognize primitive socio-emotional clues that could otherwise serve to biologically and emotionally synchronize them with people around them,’ (Molly Helt, 2010).

With biological and emotional synchronicity being such an important part of being a social animal, contagious yawning could be another way in which we empathize, communicate and ultimately cooperate with each other to form such powerful social bonds.

The jury is still out on the exact reason for yawning and contagious yawning, so if you hear of any more recent or conclusive studies please do get in touch. And for those out there who feel a blog post is a true blog post without small cute animals, here you go.

Reference

Why is Yawning Contagious? - BBC News

Yawn! Yawn! Yawn! Yawn! Yawn! Contagious Yawn! - ScienceBlogs.com/Jason G. Goldman

Why do we Yawn?  - ScienceBlogs/Grrl Scientist

Why do people yawn, and are yawns contagus -  MadSci.org

What is the Reason for Yawning? - MadSci.org