By Dr. Mercola
Yawning is usually associated with boredom or being tired, but new research suggests there’s far more to this behavior than meets the eye.
The first clue that yawning serves a much greater purpose?
We do it involuntarily, like breathing, and it starts even before we’re born (as early as 11 weeks after conception).
There are a number of theories out there for why we yawn, but one of the most compelling is being explored by a Princeton University researcher and his colleagues, whose studies suggest yawning performs the important function of cooling your brain. >