In a study published in the journal Current Biology (as opposed to Outdated Biology), researchers from the University of Nottingham (Beverley J. Brown, Soyoung Kim, Hannah Saunders, Clarissa Bachmann, Jessica Thompson, Danielle Ropar, and Stephen R. Jackson) had 36 adult subjects watch videos of another person yawning and then asked the participants to either allow or keep themselves from yawning. The researchers measured how many times the participants had full yawns and stifled yawns (you know, when you start to yawn and try to stop it.) Interestingly, telling participants to suppress yawns only increased the urge to yawn. The participant's risk of "catching" a yawn correlated with the excitability of his or her primary motor cortex, a part of the brain that controls your movement. By using external transcranial magnetic stimulation (TMS) to increase the excitability of a person's primary motor cortex, the researchers were able to make a person more susceptible to yawning. Consider such TMS as the opposite of a vaccine for yawning.
Kelly McFadden holds her son Will McFadden, 3, as he yawns as his father Trevor McFadden, nominee to be a United States District Judge for the District of Columbia, testifies during a Senate Judiciary Committee nomination hearing on Capitol Hill, June 28, 2017 in Washington, DC. (Photo by Drew Angerer/Getty Images)
The contagiousness of yawning lends further credence to the theory that yawning may be a form of communicating. Yawning in response to yawning could be a way of demonstrating empathy as in "oh, you are tired? So am I." or "you believe our date is dull, so do I. We clearly have something in common." Indeed, a study published in PLOS ONE demonstrated that people were more likely to yawn when those more familiar to them yawned compared to strangers. This would be in line with the observation that you tend to have more empathy for those who are closer to you. In fact, in a study deposited in Nature Precedings, which houses pre-publication research, people may be more likely to yawn when people of the same race or ethnicity yawn versus those of a different race or ethnicity, which is also consistent with the finding that people tend to have more empathy for those of the same race and ethnicity. Ah, will we ever see the day when we yawn at each other equally?
In Maria Konnikova's article on the science of yawning in The New Yorker, she mentioned this study and others that support the yawning empathy hypothesis. Another piece of evidence that she listed is the observation that fetuses in the womb yawn (presumably because there is no Netflix in there) but children don't really develop contagious yawning until they are older than 5 years of age, similar to when they develop empathy. Additionally, she cited studies that have shown that patients who have schizophrenia or autism, conditions that may interfere with empathy, tend to be less susceptible to contagious yawning.
However, this doesn't necessarily mean that when feeling down, you should seek out people who are yawning their heads off incessantly to find more comfort. According to a study out of Duke University published in PLOS ONE, people who were more likely to catch yawning were not necessarily more empathetic in general. Certainly, understanding communications does not always imply empathy. You could be saying, "I see that you are tired, I hear that you are tired, but I really don't care that you are tired."
Contagious yawning isn't the only form of echophenomena (automatically imitating another person's behaviors). Many other behaviors or actions such as laughing, rudeness, gestures, body positions, treating someone well or badly, and unhealthy eating can be quite "contagious." Such mirroring and mimicry can consciously or unconsciously establish rapport or conform with others. The contagiousness of so many behaviors also suggests that more chatter is going on between people than we realize. In fact, yawning seems to be so contagious that even discussing, hearing, or writing about yawning can make you......yawn. Excuse me.