Yawning Cools the Brain
In an article in the Evolutionary Psychology journal, Andrew and Gordon Gallup, of the State University of New York at Albany, present interesting findings of their yawning-experiments. Yawning, they conclude, cools the brain, accelerates blood circulation and thereby increases attention.
According to our hypothesis, rather than promoting sleep, yawning should antagonize sleep. It has been widely believed that yawning in the presence of others is disrespectful and a sign of boredom (e.g., witness the fact that many people cover their mouths when they yawn). However, according to our account yawning more accurately reflects a mechanism that maintains attention. Likewise, when someone yawns in a group setting as evidence for diminished mental processing efficiency, contagious yawning may have evolved to promote the maintenance of vigilance.
