The Communicative Implication of Yawning
The Yawn is a reflex which consists in the deep inhalation of air accompanied by an open mouth, tightened cheek muscles, eye closure, and tearing.
Yawning is involuntary; it includes ‘closing of the eyes and lowering of the brows’ (Brannigan and Humphries, 1972).
It is the nature of humans to yawn; especially when we are tired and blood oxygen is low; in a tense setting, adrenaline lowers the blood’s oxygen level and yawning speeds re-oxygenation. In our attempt to conceal a yawn, we turn our head or hold the mouth more closed than it actually wants to be.
Yawning is more common in adults as the result of sleepiness due to fatigue or tedious activities, boredom, emotional conflict, or even hunger.
In tense business meetings, for instance, yawning is a sign of mild anxiety, disagreement, or uncertainty. When alert listeners yawn in response to controversial suggestions or ideas, the yawn signals a probing point, that is, an opportunity to explore unverbalized objections or clarify unvoiced concerns.
In animals, yawning can serve as a warning signal. For example, Charles DarwinOpens in new window, in his book The Expression of the Emotions in Man and AnimalsOpens in new window, mentioned that baboonsOpens in new window yawn to threaten their enemies, possibly by displaying large canine teethOpens in new window (WikipediaOpens in new window).
Yawning is highly contagiousOpens in new window, and that when one person yawns, other people nearby are very likely to follow suit. Research has shown that it does not require a complete yawn for one person to copy another—the mere sight of an open mouth, or the sound of a yawn, is often enough to get other people yawning.
During a yawn, the tensor tympani muscleOpens in new window in the middle ear contracts, creating a rumbling noise from within the head. Yawning is sometimes accompanied, in humans and animals, by an instinctive act of stretching several parts of the body, including arms, neck, shoulders and back (WikipediaOpens in new window).