Oh, excuse me!
Have you ever yawned because somebody else yawned?
You aren't especially tired, yet suddenly your mouth opens wide and a big yawn comes out.
This phenomenon is known as contagious yawning.
And while scientists still don't fully understand why it happens, there are many hypotheses currently being researched.
Let's take a look at a few of the most prevalent ones, beginning with two physiological hypotheses before moving to a psychological one.
Our first physiological hypothesis states that contagious yawning is triggered by a specific stimulus, an initial yawn.
This is called fixed action pattern.
Think of fixed action pattern like a reflex.
Your yawn makes me yawn.
Similar to a domino effect, one person's yawn triggers a yawn in a person nearby that has observed the act.
Once this reflex is triggered, it must run its course.
Have you ever tried to stop a yawn once it has begun?
Another physiological hypothesis is known as non-conscious mimicry, or the chameleon effect.
This occurs when you imitate someone's behavior without knowing it, a subtle and unintentional copycat maneuver.
People tend to mimic each other's postures.
If you are seated across from someone that has their legs crossed, you might cross your own legs.
This hypothesis suggests that we yawn when we see someone else yawn because we are unconsciously copying his or her behavior.
Scientists believe that this chameleon effect is possible because of a special set of neurons known as mirror neurons.
Mirror neurons are a type of brain cell that responds equally when we perform an action as when we see someone else perform the same action.
These neurons are important for learning and self-awareness.
For example, watching someone do something physical, like knitting or putting on lipstick, can help you do those same actions more accurately.
Neuroimaging studies using fMRI, functional magnetic resonance imaging, show us that when we seem someone yawn or even hear their yawn, a specific area of the brain housing these mirror neurons tends to light up, which, in turn, causes us to respond with the same action: a yawn!
Our psychological hypothesis also involves the work of these mirror neurons.
We will call it the empathy yawn.