Walt O'Reagun
Walt O'Reagun answered Gokula krishnan's question

People actually yawn to get ready for ... Something.
It doesn't have to do with sleep, as most people think.

And yes, it is an ingrained social condition that if you see someone yawn, you will want to.  Because if CavemanA yawns to get ready for ... Something - then CavemanB should probably get ready, also.

There are … Read more

Darik Majoren
Darik Majoren answered Gokula krishnan's question

Depends upon the time of day and your hydration. Also, yes; yawning is one of those things that can trigger or cue a response in our species. It may not be immediate but most people response to seeing another person yawning and reciprocate the gesture.

Fun fact, most psychopaths do not have the same response … Read more