Yawn

The sound of yawning

Yawning

---

Yawning

---

Problems playing these files? See media help.

A yawn is a reflex. It involves a large, long taking in of air, the stretching of eardrums as the jaw opens wide, and last a (sometimes loud) breathing out. Pandiculation is the act of yawning and stretching simultaneously.^[1] It is easy to see when someone is yawning, but no-one knows what its function is but it may serve as a way of communication.

Yawning is commonly associated with tiredness, stress, overwork, lack of stimulation and boredom. In humans, yawning is often triggered by others yawning (e.g. seeing a person yawning, talking to someone on the phone who is yawning) and is a typical example of positive feedback.^[2] This "infectious" yawning has also been observed in chimpanzees and dogs.^[3][4] Cats both yawn and stretch, though not necessarily at the same time.

1. ↑ MedOnline.net Archived 2007-05-02 at the Wayback Machine, "pandiculate"
2. ↑ Camazine, Deneubourg, Franks, Sneyd, Theraulaz, Bonabeau 2003. Self-Organization in Biological Systems, Princeton University Press, 18. ISBN 0-691-11624-5
3. ↑ Carpenter, Jennifer (August 5, 2008). "Pet dogs can 'catch' human yawns". BBC NEWS. Retrieved 2009-10-03.
4. ↑ Shepherd, Alex J.; Senju, Atsushi; Joly-Mascheroni, Ramiro M. (2008). "Dogs catch human yawns". Biology Letters. 4 (5): 446–8. doi:10.1098/rsbl.2008.0333. PMC 2610100. PMID 18682357.