What Makes People Yawn?

Featured Article, Trivia
on September 5, 2013

You’re in the middle of a meeting or seminar, listening intently to the speaker as he talks on and on, when suddenly, you yawn. Then, inexplicably, one of your colleagues yawns. Then another. Then the speaker himself begins to yawn, which makes you yawn again. What happens? What makes people yawn? Is yawning simply the manifestation of our boredom or fatigue? Or does it have a specific purpose?

Yawning is thought to be an involuntary reflex, but its purpose and causes are not entirely understood. This is not to say that there is a lack of interest in the science of yawning—in fact, the first international conference on yawning was held in 2010—but rather that experts are still exploring several possibilities.

Some experts have proposed that yawning serves as a method of moderating the temperature of the brain, while others suggest that yawning increases oxygen levels when needed.

“It’s commonly thought that yawning helps to increase oxygen levels in the body,” says Francesca Gould, lecturer in anatomy and physiology and author of “Why is Yawning Contagious?” “However, research has shown that participants that were placed in a room with lots of oxygen yawned as frequently as those in a room with less oxygen, which suggests that yawning isn’t necessary to help increase body oxygen levels.” Sonography also has shown that babies yawn while still in the womb, an environment in which oxygen could not be obtained by yawning.

Then why do we yawn?

“Some experts suggest that yawning helps to keep us awake or remain alert,” Gould says, noting that people often yawn while driving at night. It’s also been suggested that some people yawn in response to feelings of nervousness.

Another element in the yawning conundrum is the occurrence of contagious yawning. In fact, chances are good that you’ve yawned at least once while reading this article. Yawning can be triggered by any number of things—including the sight of someone yawning, the sound of someone yawning or even the suggestion of yawning.

Yawning is considered rude and often interpreted as a sign that we’re not enjoying the present company, but that’s not always the case. It could be a leftover link to our primitive lives as studies have shown evidence of contagious yawning in animals, including chimpanzees and dogs.

“It’s interesting [that] people will yawn if they hear, read, or think about yawning,” Gould says. “Some experts think yawning is a non-verbal signal to others, and may been part of primitive humans’ social behavior to indicate to others that it was time to sleep, and others would respond by yawning.”