Why is yawning contagious?

Question

If I hear some one yawn I will too. And vise-versa.

Answer 1

its inner conscience tat makes u yawn wen u see someone yawnin ..u yawn wen u have short of oxygen ...try to hold ure breath for few secs ull find ureself yawning ,,,wen other person sees u yawning unknowingly the mind thinks u will fall short of oxygen and therefore it sinds msgs to ure brain to yawn so tat even u can take in oxygen u require..

Answer 2

There is no clear answer to this yet, but researchers have made some interesting theories, most of which relate to "herd instinct". For example, one theory is that it is to encourage synchronized sleeping patterns and times of activity. Further, it can indicate which members of a given herd are tired - so say me and you were with a group of friends out at night, and I yawned, and then you yawned after seeing me, our friends would likely think we were tired, so we'd go home and sleep. Our friends might even realise after seeing us yawn that they too were tired, so it could also encourage group mood behaviour. The same applies to animals of course, but obviously more practically.

Another theory is that, because yawning reveals your teeth, it can be seen as a sort of threat or warning on a subconscious level. This has been observed in primates, so could very well apply to us humans.

In short: there is no straight answer, but certainly some interesting possibilities!

Answer 3

yes you are somewhat right ;this is a condition when a person feels tired;according to a reaserch when high dose of carbondioxide collects in a part of our brain by yawning we take a deep breath more oxygen and expell that carbondioxide all this is due to tisse exhasution; due to psychogenic effect other nearby person also feels exhausted and yawns;

Answer 4

YEah, I just yawned reading about it.

Answer 5

is it? never heard of that yet.