It's been suggested contagious yawning could be a result of an unconscious herdi...

nreece on Dec 15, 2008 | parent | context | favorite | on: The Yawn Explained: It Cools Your Brain

It's been suggested contagious yawning could be a result of an unconscious herding behaviour - a subtle way to communicate to those around us, similar to when flocks of birds take flight at the same time.

http://news.bbc.co.uk/2/hi/uk_news/magazine/6270036.stm