Why Do We Yawn?
Reviewed: Dr. Gromatzky
8. On Guard
It was not that long ago, relatively speaking, that human beings lived in the wild. As such, many of our behaviors today are survival instincts, and this might include yawning. In the wild, we would not have had the security of sleeping behind locked doors.
This would have meant there was a need for some people to take it in shifts to do sentry duty to keep people safe, especially considering there would have been wild animals around. It might be that yawning was a way of signaling to others that a sentry is tired and that somebody else should take their place.
Advertisement
