Why do we yawn? It's an age-old question that intrigues us all. Whether it's in the middle of a meeting, half way through an important conversation or when you're concentrating really hard - we've all experienced an awkward yawn! Read on to find out more about the science behind the yawn.
Why do we yawn?
We typically yawn when we're bored, or tired, and this may be down to the amount of oxygen we inhale. When we breathe we tend to breathe deeply, inhaling as much oxygen as possible, however when we're bored or tired our breathing slows down taking in less oxygen. Yawning is our body's way of telling us that we need more oxygen in our blood and less carbon dioxide.
It can be argued that this theory of 'brain oxygen' is a myth and really, when we yawn, we're just trying to cool our brain down. Some scientists suggest that we yawn as soon as we wake up in the morning because the temperature of our brains at the highest in the morning so we need to cool it down.
Are yawns contagious?
Scientists suggest that 'mimicking' another person's yawn may tie into trying to cool our brain down. When we notice someone yawning, it reminds us about our breathing routine and that we haven't yawned in a while. By thinking of this, the temperature of our brain rises and we then yawn to cool it down.
Another theory suggests that as humans we feel empathy towards one another, leading us to mimic emotions. For example, when talking to an upset friend who is complaining about their day and their emotion is shown through frowns and downward eyebrows, we mimic their emotion in order to imitate their sadness and this is the same when yawning. This is just our brain's natural way of reacting to what it's being told and how it's being told.
Even though it appears our yawns are contagious between everyone, psychologists at the University of Stirling suggest that babies and young children are immune to catching our yawns. Instead, they just yawn spontaneously. Research has suggested that children don't start to 'catch yawns' until they reach around five years old when they start to understand the ability to empathise.
When do we start yawning?
We start yawning from a young age, a very young age…taking us back to our time in the womb in fact. 20 weeks after conception, babies inside the womb are constantly yawning but this isn't linked to tiredness or boredom; it is believed to help stimulate the development of the brain. It must be tiring lay in the womb all day! The youngest unborn babies can yawn up to six times an hour… how cute!
The father of medicine, Hippocrates, theorised that our yawning routine is dependent on our health. He believed that when we yawn, it is our body trying to remove any infectious and harmful bacteria from our lungs. However, later research revealed that yawning doesn't impact on our respiratory system.