The science behind the yawn
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
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
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
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