- Yawning is the act of simultaneous inhalation of air & stretching of the eardrums, followed by exhalation of breath.
- The average yawn lasts about 6 seconds.
- It's an involuntary reflex.
- It has an infectious quality (an example of positive feedback mechanism)
- There's no concrete reason as to why we yawn: several factors include fatigue, boredom & drowsiness.
- A fetus in the womb yawns, beginning from as early as 11 weeks of development.
- The word "yawn" is from the Middle English word yanen.
- Humans yawn on average 10 times a day.