Similar to the howling of the wolf pack, which is designed to synchronize mood in gregarious animals, yawning would have signalled tiredness to other members of the tribe thousands of years ago.
for more: http://thezenstones.blogspot.com/2011/11/why-is-yawning-contagious.html
Minnesota.
none
main
if rude and yawning are defined as such i don't see any reason why the act of yawning be rude. yawning is physiologic. would urinating and defecating be rude also?
Yawning is not a disease.
Texas
Maine
The spelling of the yawning sound is "yawn."
Two states qualify as being outside the contigous US, Alaska & Hawaii. This means they do not make direct contact with the 48 on the main north American content.
jamaka
Contiguous is pronounced kon teeg yew us
yes.