Experts May Have Figured Out Why We Yawn
One of human physiology’s great mysteries may be solved, finally.
Yawning is a mystery that has long defied explanation.
Along with humans — who begin yawning in the womb just 12 weeks after conception — most other living things also yawn. That includes dogs, cats, and other mammals, but also birds, reptiles, and amphibians.
Any behavior that exists so broadly within the animal kingdom must serve a purpose, but experts have struggled to determine what that purpose could be. There have been many hypotheses, but so far none has stood up to rigorous scrutiny.
‘Social yawning makes up just 10 percent of yawning episodes, so I don’t think the social part is the main function of yawning.’
Human beings yawn when they’re sleepy, but also when they’re first waking up. The association between yawning and drowsiness led some researchers to guess that yawning helps regulate the brain’s temperature. While there may be something to this, the so-called “brain-cooling hypothesis” hasn’t panned out in follow-up work.
Other researchers have shown that yawning is more likely to take place during periods of high stress — such as during…
