Why is is that when some people yawn, others yawn too?

Answer 1

Actually there are a few theories on yawning. Some say that it is your body's way of getting more oxygen into your bloodstream and for those that say that. For those folks, I've got nothing for you.
There is another theory, yawning was an early form of communication, before humans could verbally communicate yawning was a way of doing so. The return of another's yawn would account for this. Subconsiously we may be answering others.

Answer 2

I believe that when someone yawns after someone else has it is mainly a coincidence. There is nothing that can cause it to spread to make other people yawn.

The only reason other people are yawning is because they are all in the same situation that can cause them to yawn.

It is a simple answer but it makes sense to me.

Answer 3

Mythbusters Episode 28: Is Yawning Contagious? "Using a specially fabricated chamber complete with two-way mirror and a hidden camera, Kari, Scottie and Tory set out to see whether a yawn, like a cold, truly can be caught". I found their findings inconclusive.

Answer 4

Mere coincidence. You yawn because you do not have enough oxygen, so your body makes you yawn...intaking a lot of air without having to breathe out CO2. Simple, yet effective, no?

Answer 5

As soon as I read your question, I yawned!

Answer 6

I don't know, but reading your question made me yawn.

Answer 7

Myth-busters did find something they said something in your brain subconsciously causes you to mimick the yawning person.

Answer 8

I've heard that it's a lack of oxygen in the air. It makes sense, because that would effect everyone in the room.

Answer 9

Changes in the air pressure, inside and outside of the body. Also, when the body lacks oxygen...!

Answer 10

Chain reaction