Why do we yawn? Obviously, people and other animals yawn when they are tired; we all know that. But there must be more to it—there must be a biological purpose beyond letting chatty dinner guests know that they’ve overstayed their welcome.
Let’s consider three possible functions and the likelihood of each:
First, [speed skater] Apolo Ohno believes that it improves athletic performance. Ohno once told Yahoo Sports that yawning makes him feel better, that it “gets the oxygen in and the nerves out.”… Yawning, as far as we know, does not improve overall oxygen levels.
Second, based on brain-scan studies, yawning increases the activity of a small area of the brain called the precuneus, which plays an important role in spatial orientation, memory, and consciousness. So, perhaps it helps with focus and attention.
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And third, there is the social function of yawning. Yes, it may be a social cue to bug off, but depending on the circumstances, it may also be a call for vigilance…. This signaling function may also actually extend beyond vigilance and to empathy. Interestingly, children with autism-spectrum disorders seem to have an impaired ability to contagiously yawn.
