About half of you who are reading this article right now will feel like yawning! I hope it is not because you didn’t get enough sleep last night, or because you are already bored reading this article! Did you know that to pandiculate means to yawn and stretch at the same time? See if you can use that word in a conversation this month without making the person you are talking to yawn! Why is it that when we see, hear or even read about somebody yawning we often have an intense desire to yawn too?
We are social beings, and so the clue as to why we have the urge to yawn when we see others yawning is in the way our brains are wired and how our brains relate to each other. In fact, neuroscientists, with the use of brain scans over the last decade, have confirmed that humans and animals have a network of brain cells called mirror neurons that turn on at the sight or thought of somebody else doing something, which causes a similar feeling or action in us! As adults, we can often suppress the desire to mimic the actions or emotions of others because the front part of our brains (the prefrontal cortex) is more developed in us than in children. Remember the last time you saw a toddler start to cry and soon after all the other toddlers began crying too? This is because in small children the prefrontal cortex has not yet fully developed and so they cannot efficiently tell the difference between another person’s feelings and their own feelings.
Where then, does the mirror neuron network develop in the brain, and what evolutionary advantage does it hold over us as adults (I hope you have stopped yawning now!)? The mirror neuron system is in the prefrontal and body sensation (somato-sensory) areas of the brain that help us to imagine the bodily sensations of others.
Some scientists believe that this brain network, shared by humans and many animals, might be related to empathy – the ability to mirror and feel how somebody else feels. So, if a loved one stubs their toe, your own toe might start to tingle and your eyes might start to water! In fact, the degree to which the mirror neuron network activates in baboons that yawn to the sight of other baboons yawning directly relates to the amount of time baboons spend grooming each other, and therefore how close they feel to each other. This might suggest that the closer you feel towards another person the more likely they are to make you yawn!
But the jury is still out among neuroscientists regarding the precise function of mirror neurons in the brain that make us yawn when we see somebody else yawning. Mirror neurons may help us to understand the intentions of others, help us to learn, help us to put ourselves in someone else’s shoes, enable us to have greater self-awareness and allow us to acquire language skills. But what about yawning in particular – why are our brains so interested in mimicking a yawn? It might be that yawning indicates the lowest level of threat – animals that yawn are communicating a reduced feeling of aggression and reduced energy. And contrary to popular belief often portrayed in modern media, it might be that humans are driven to feel a reduction in aggression and so the brain is wired to reciprocate that feeling.
Dr Samantha Brooks is a neuroscientist at the UCT Department of Psychiatry and Mental Health, specialising in the neural correlates of impulse control from eating disorders to addiction. For more information on neuroscience at UCT and to contact Samantha, see www.drsamanthabrooks.com.
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