You’re sitting across from your friend in a quaint eatery downtown. You two are enjoying your food between occasional sips of your raspberry iced tea, engaging in jovial conversation. It was a long time coming. With adulthood and its throes, it was refreshing that you two could finally find quality time to spend together.

“Man, today was a long day,” she remarks, her dinner finished 5 minutes prior.

“Same here,” you respond empathetically, eating the rest of your strawberry cheesecake.

She nods in agreement and her hands move from her lap to the front of her mouth. Her fingers doing a poor job covering the audible yawn that escapes from underneath.

And as if possessed by a demon that flew out of her mouth to enter yours, sure enough, you’re yawning too.

If a yawning demon isn’t responsible for this reflex, then what exactly makes yawning contagious?

As I considered this question, the first body part that came to mind was the mirror neuron. Mirror neurons are the part of our nervous system that fire whenever we imitate the behaviors that we see. Given its role, it is no wonder that mirror neurons are critical in things like learning, empathy, and language. And it turns out that my hunch concerning mirror neuron function in contagious yawning was pretty spot on.

Mirror Neurons and Contagious Yawning

In 2012, Dr. Helene Haker, Dr. Wolfram Kawohl, Dr. Uwe Herwig, and Dr. Wulf Rössler published a study that explored contagious yawning. In their study, eleven adults volunteered to view videos of people yawning, laughing, and having neutral facial expressions. The scientists also chose to show the test volunteers static images of scrambled faces as the visual baseline. The scientists monitored the volunteers’ brain activity via fMRI, displaying various facial expressions in front of them.

When the volunteers saw people yawning, the scientists observed that the Brodmann’s area 9 region of the brain lit up, a section of the frontal lobe. It is also a part of the mirror neuron system (MNS). They went on to say:

“Our results emphasize the connection between the MNS and higher cognitive empathic functions, including mentalizing.”

Mentalizing happens when we consciously and subconsciously try to make sense of others and ourselves.

About three years prior to when the above study was published, another study validated the idea that hearing people yawn was contagious, also activating the MNS.

So if we refer to the scenario at the beginning of this article, we can say that it wasn’t just seeing her yawn that may have made you yawn. Hearing her yawn could have played a part too.

Are Humans The Only Species That Experience Contagious Yawning?

While all vertebrate animals yawn spontaneously, it’s not only humans that participate in contagious yawning. As one may expect, primates such as chimpanzees, macaques, and baboons, experience it too. Given the genetic similarity among these primates, including humans, perhaps it is not surprising that they would also experience this phenomenon. Yet outside of the great apes, we find another set of critters that also demonstrate this same ability.

They are most commonly referred to as man’s best friend.

Contagious Yawning in Dogs

In 2008, a study published in the Biology Letters journal demonstrated that dogs show this ability. In this study, the scientists showed the dogs videos of humans yawning and pretending to yawn. Out of those twenty nine dogs, twenty one of them yawned. But when the human made mouth movements that acted as the control of the experiment, none of the dogs yawned. As it turns out, humans aren’t the only ones that find auditory yawning contagious. Dogs do too! In a study published in 2012, scientists found that not only did dogs yawn as a response to human yawns; they yawned more frequently at yawns that were familiar to them.

When looking further up into the ancestry of our beloved four legged domestic canine, we find wolves. And findings conclude that they, too, participate in contagious yawning. Scientists Teresa Romero, Marie Ito, Atsuko Saito, and Toshikazu Hasegawa noted this. They also discovered that the reaction time in female wolves was shorter than that of male wolves. And with the presence of this trait in dogs and their ancestors and among humans and other primates, the scientists in the wolf study say that it is possible that this trait is a marked component of evolutionary history among mammals. They also think it might be a case of convergent evolution between dogs and humans; that is, despite not being closely related evolution-wise, they managed to evolve the similar characteristic of contagious yawning. And if not that, then it is due to the social closeness between humans and domesticated dogs.

What Contagious Yawning Says (And Does Not Say) About Empathy

All of the studies I’ve mentioned so far have indicated (at the very least) a possible link between contagious yawning and empathy. And it makes sense why. The first study I introduced mentioned the link between mirror neurons and empathic functions. And mirror neurons are activated during contagious yawning. In humans, chimpanzees, bonobos, dogs, and wolves, social closeness played a substantial factor in the increased frequency of yawning. And it goes without saying that we tend to feel more empathy for the people we feel more emotionally tied to.

However, with these studies and plenty others, Dr. Jorg J.M. Massen and Dr. Andrew C. Gallup have their reservations. In their review journal article titled Why contagious yawning does not (yet) equate to empathy, they looked at dozens of studies that explored the contagious yawning-empathy link. They concluded that the results were inconsistent and inconclusive, encouraging more controlled studies in the future.

A Closer Look at the Inconsistencies

In human studies, Massen and Gallup note that several factors impact the results. But before we get to that, it seems like they didn’t exactly agree with the premise of these contagious yawning claims to begin with:

…while these studies claim that they show the activation of particular brain regions involved in [contagious yawning], what they actually show is how the brain reacts to sensing yawns in others.

Possible Flaws in Contagious Yawning Experiments in Humans

On the surface, their assessment may just seem like semantics. But this observation sets the foundation for their inconsistency claim. While the brain may respond a certain way, the physiological responses of the volunteers will differ. For example, in the imaging studies, the volunteers did not move as per the scientists’ instructions. Movement could impact brain scans. However, that restriction could also impact whether or not the volunteers yawn in the lab when they would have otherwise yawned in a different setting. Massen and Gallup also considered the social stigma of yawning, how it’s often seen as rude or disrespectful. And it’s possible that some volunteers may have this behavior so ingrained that they didn’t yawn in these lab studies.

In the review, other studies claimed that contagious yawning waned with age. The general pattern of empathy correlates with the frequency of contagious yawning from juvenile age to adulthood. From there, someone could make the conclusion that the link between contagious yawning and empathy is founded. However Massen and Gallup say that yawning as a whole decreases with age. Auditory and visual abilities may also decline as well, so several factors could contribute to decreased response.

Possible Flaws in the Contagious Experiments in Nonhuman Primates and dogs

When it came to nonhuman primates, they noted that “even though all studies on chimpanzees indeed do report [contagious yawning], results on bonobos are inconsistent, and the only study on gorillas and orangutans to date found no evidence for [contagious yawning] in these species.”

As mentioned earlier, these species are closely related since they are primates. However, given this and the inconsistency of contagious yawning among them, Massen and Gallup state that making evolutionary relationship claims as the reason for contagious yawning is a bit premature.

In order to get more precise readings on contagious yawning in dogs, Massen and Gallup propose eye-tracking devices that let the observer in on what they are paying attention to. This test could also work on other animals like nonhuman primates and humans as well.

Autism, Empathy, and the danger of unfairly discriminating against people with autism

If the scientists claim a contagious yawning-empathy link, then, according to the “contagious yawning and autism” studies, people with autism do not experience contagious yawning. From there, someone could conclude that people with autism experience little empathy. Considering how high society regards empathy and since psychopathy is characterized (among other things) by lacking empathy, one could easily (and unfairly) stigmatize people with autism given these findings. However, in a study by Dr. Senju and his colleagues, Massen and Gallup noted in their review that “when children with ASD were specifically instructed to fixate on the eyes of the stimuli they were just as likely to yawn in response to [contagious yawning] stimuli when compared to typically developing children.”

I also appreciate this other article that mentioned the difference between autism and psychopathy by saying the following:

“Whilst psychopathy appears characterized by problems with resonating with others’ emotions, ASD appears characterized by problems with cognitive perspective-taking.” “…high psychopathic traits relate to problems with resonating with others’ emotions, but not cognitive perspective taking. Conversely, high ASD traits relate to problems with cognitive perspective-taking but not resonating with others’ emotions.”

Cognitive perspective-taking is basically the ability to deduce someone else’s thoughts. But resonating with others’ emotions–an integral part of empathy–is a characteristic of people with autism. It is also brings a better perspective on those who suffer from psychopathy. That they are not inherently malicious. Their brains are constructed differently and results in lacking inherent empathy. Various therapies exist in treating both autism and psychopathy as needed.

Not All Is Lost

The lack of consistency and a need for more controlled studies do not automatically mean that we should discard all possibility of the link between contagious yawning and empathy. Those scientists could totally be onto something. But thanks to the review by Massen and Gallup, we find great room for improvement. They point out the need to use a more multifaceted approach in observing empathy, using cognitive vs. emotional and multiple subjective and objective measures, for example. Also, since spontaneous yawning and contagious yawning look the same on the outside, it may also look similar at a neurophysiological level. In other words, it is possible that some test volunteers in these studies yawned spontaneously (i.e. they yawned on their own). And the scientists mistakenly recorded that their volunteers contagiously yawned. Massen and Gallup encourage an experimental design that distinguishes the two as much as possible.

Did any of these studies make an impression on you? If so, which ones? Please share with me in the comments section below.