By Lauren Donley

    On average, adults yawn between 10 and 20 times per day. We tend to associate yawning with tiredness, and this is largely an accurate assessment. Research shows that we yawn more when transitioning in and out of sleep – that is, when we’re falling asleep or waking up. However, we also yawn when experiencing certain feelings or emotions, or in response to some medications. And yawning is also contagious.

    Contagious yawning can occur when we see or hear someone else yawn. Or even when we simply think or read about yawning. Like right now. Go on, you know you want to! It’s a neat trick for sure, but it also raises a perfectly reasonable question: what on earth is the point of a contagious yawn? Luckily, there’s an entire scientific field dedicated to the study of yawning, known as chasmology. 

    Catch and release

    Firstly, let’s unpack a standard yawn. While chasmologists haven’t been able to agree on a single explanation for spontaneous yawning, the research points towards a few logical functions: increasing blood flow to our heads, cooling our brains, and generally giving us a boost when we’re feeling sleepy.

    A combination of these factors is also thought to explain contagious yawning. One popular theory is that passing on a yawn is a primitive type of communication that helped our ancestors to remain alert and avoid danger. This theory is supported by the fact that contagious yawning is also observed in a number of animals that live cooperatively, such as chimpanzees, wolves, dogs, elephants and lions.

    A similar phenomenon occurs when we find ourselves scratching, laughing or crossing our legs in response to others doing the same. Also known as ‘social mirroring’, this form of imitation is driven by groups of ‘mirror’ neurons in our brains. These neurons fire not only when we copy the actions of others, but also when we see others copying us.

    Empathy and psychopathy

    Another theory is that contagious yawning is linked to expressing empathy, and allows us to unconsciously share feelings such as stress, boredom and anxiety – all of which are known to trigger yawning. It should be noted that one expert has described this theory as ‘perhaps the most hotly debated area of yawn research’. However, there are multiple lines of research that support the idea.

    For example, at least two studies have shown that contagious yawning is more likely to occur around family and friends than in the company of strangers. Another study showed that contagious yawning usually begins to appear in children at around the age of four, which coincides with the development of empathy skills.

    More recently, the largest study on yawning and empathy to date found that people who lacked a contagious yawning response scored higher on three different tests used to measure psychopathy. The study enrolled 452 people, including a mix of university students and other members of the public.

    If this finding has you examining your personality for psychopathic tendencies, you can probably rest easy. The study also showed that self-reported tiredness was the strongest predictor of contagious yawning. So, if you’ve read this far without a yawn, it’s unlikely that you’re a psychopath – you might just be well rested. 

    Human Interest
    Human Interest
    Welcome to your regular column on the science of human beings…and being human. Brought to you by Lauren Donley, an unashamed science nerd who never misses an opportunity to share a story about bodily functions. Please note that this article is for general interest and is not a replacement for medical care. If you have any questions or concerns about your health, please contact your doctor.

    Your feedback

    Please enter your comment!
    Please enter your name here



    Latest Articles

    Latest edition

    #96 May 2024

    Recent editions



    Become a supporter

    The Westsider is run on the power of volunteers. Your contribution directly contributes to ensuring we can continue serving and celebrating our community.

    Related articles