The Yawn, A Fan for Your Brain

This is fascinating.  I have long wondered why we yawn, and remember my dad explaining that it was something about the brain needing more oxygen (which is kind of true) but now new findings, as detailed in this discovery news article, strongly suggest that yawning developed as a mechanism to cool brains.  The analogy of a computer overheating is quite great, especially considering that the brain really kind of is a very advance biological computer.  I also like the reasoning for why we often yawn when other people yawn, or even when we just read about yawning.  It seems that it evolved for group animals all to remain alert for danger (the cooling of the brain helps it function better).  Great stuff.