I’ve always wondered why yawning is contagious but i never would have guessed this:
New research suggests rather than being a precursor to sleep, the purpose of yawning is to cool the brain so it operates more efficiently and keeps you awake.
The brain cooling theory says that when we contagiously yawn we are participating in an ancient, hardwired ritual that evolved to help groups stay alert and detect danger.
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.
Another theory suggests contagious yawning might have helped early humans communicate their alertness levels and co-ordinate sleeping times.
Basically, if one decided it was time to sleep they would tell the others by yawning and they would do it in return to show they agreed.
Hmm interesting! bet this post made you yawn though!!!