I have read or heard of a variety of explanations as to why we yawn:
- Need a stretch
- Need oxygen
- Need to cool the brain
- Need power (make everyone who sees you yawn do it too!)
- Changes in the chemicals (neurotransmitters) in the brain that affect emotions, mood, appetite, and other phenomena.
- Health issues such as adrenal issues, diabetes & stroke
- Could be a herd instinct that synchronizes mood in gregarious animals.
For me right now, I know it’s reason #1. G’nite!
(Do tell, did you yawn too?)