Is it true that we yawn when our brains are deprived of oxygen? Most of us can feel a yawn coming on. The muscles in our jaw begin to tighten, our nostrils might flare, and our eyes might tear up as ...

Why do we yawn? Yawning is a universal gesture. Everyone yawns, from babies still in their mother's womb to the elderly. However, the exact reasons for this reflex are not well understood. Is it just ...