The body yawns for three reasons, it’s telling you your ether hungry, tied means you need sleep and when you wake up!! Yes I guess we all do that when someone is laughing we end up laughing too!!
I agree with you Ayegbayo. I do that quite a lot. Even when I am on the phone if the person I am speaking too yawns I do yawn as well. Very interesting and amazing I should say.
Both yawning and laughing are contagious, but yawning is generally considered more universally contagious. Seeing, hearing, or even thinking about yawning can trigger it.