Why is "Yawning" Contagious?

Just a question that popped up in my office this morning when I yawned.... does anyone know why yawning is contagious?
Answers:
An involuntary exploit in the brain, causes us to yawn when watching others do it. Source(s): I Googled
Nobody really knows, but within is some thought that yawning was a pre-language method of communication. Scientists believe that it may have been a signal to the other member of one's tribe, that it's time for bed.

Interestingly enough, it's not contagious from species to species, but all vertebrate species yawn, and it's contagious within respectively species. So, while your dog won't yawn just because you do, if your dog did yawn, the dogs near him would, too.

Related Questions:
What to do for reduice URIC ACID surrounded by blood?   Can these abet me not repeal from oxycontin?   Can someone please help out me beside my 200 pg daily on the history of pills?   To pass by a drug try-out can you use powder pectin surrounded by gatorade or does it hold to be fluid pectin?   Question in the region of morphine?  
  • How to dilate pupils?
  • In home urine drug trial?
  • What gentle of pill do they flog over the counter that make you throw up?