Psychology of yawning: Psychology says the person who yawns right after you do isn't just tired; a 2011 study found contagious yawning is tied to empathy, and you catch it most from the people you're closest to

You're at dinner with your best friend, half listening to the story, when they let out a big yawn. Before you realize it, you're yawning too. The same probably happens when you are with your mom, your sibling, or your partner. But when a stranger yawns next to you on the subway, you barely notice, much less catch it yourself.

That difference appears to be real. According to a 2011 study, ‘Yawn Contagion and Empathy in Homo sapiens,’ published in PLOS ONE by researchers Ivan Norscia and Elisabetta Palagi at the University of Pisa, catching someone's yawn isn't random at all. It may depend heavily on how emotionally close you are to that person.

The study behind the yawn
Across 2010 and 2011, the two researchers spent a year watching 109 adults (56 women and 53 men) from Europe, North America, Asia, and Africa silently going about their normal business in workplaces, restaurants, waiting rooms, and shared meals. The subjects didn’t know they were being watched, according to the PLOS ONE study.


The researchers recorded the time each person yawned, who yawned first, everyone within earshot or eyesight, and if anyone yawned back in the next three minutes. They also measured the relationship between each pair, which they classified into four categories: strangers, acquaintances, friends, and kin, with kin defined as relatives with a genetic relatedness of 0.25 or higher, plus life partners.

The team recorded 613 yawning episodes in total, but narrowed their analysis to 480 episodes in which the response could be definitively linked to a particular trigger, the study noted.

Closer bonds, stronger contagion
That same PLOS ONE research also found that the strength of the social bond was the single biggest predictor of whether a yawn would spread from one person to another, more than gender, nationality, or even the setting in which the interaction occurred. The closer the tie, the greater the likelihood of contagion, increasing in a definite pattern from strangers to acquaintances to friends to kin.

The researchers didn't stop at whether people caught the yawn. They also logged how many times it happened and how fast. The study found that 48 dyads with multiple instances of contagion showed a higher frequency of contagious yawning among those with closer relationships. About 39 percent of the opportunities were met with yawns from acquaintances, about 52 percent from friends, and about 85 percent from kin.

Timing followed the same trend. An analysis of 149 contagious yawning episodes showed that strangers and acquaintances took significantly longer to yawn back than friends and family, whose responses were quickest.

One thing that made no real difference, according to the study, was how the yawn was perceived. It made almost no difference whether the subject was facing the yawner directly or at an angle, and whether they heard it, saw it, or both. In this dataset, contagion was also not predicted by gender, although women are typically reported to score higher on measures of general empathy.

Why researchers linked this to empathy
The idea that yawning is linked to empathy is not new. According to the study's authors, empathy in humans is thought to follow the same gradient, with the strongest empathy between kin, then close friends, then acquaintances, then strangers. The yawn contagion data showed the same pattern, and the researchers said that contagious yawning may be a behavioral signal of the same emotional wiring that makes people more in tune with those they are closest to. A write-up of the findings from ScienceDaily quoted co-author Elisabetta Palagi describing contagious yawning as tied to social bonding.

It's worth remembering this was an observational study. The researchers observed natural behavior, rather than conducting a controlled experiment in a laboratory setting, so the results imply a strong link between closeness and yawn contagion, but do not necessarily prove that empathy itself is the cause of the yawning.

Why do some scientists remain cautious
Not everyone in the field accepts contagious yawning as a settled proxy for empathy. In a review titled ‘Why contagious yawning does not (yet) equate to empathy,’ published in 2017 by Neuroscience & Biobehavioral Reviews, researchers Jorg Massen and Andrew Gallup found that, across multiple studies, evidence that links yawn contagion to empathy has been inconsistent and inconclusive overall, and that visual attention and social inhibition may also play a role in whether a yawn is contagious. Their review is a good reminder that one study, however well designed, rarely settles a question in psychology.

What this means for your next family dinner
None of this means every yawn at the office is meaningful. When a coworker you don’t know yawns, they could actually be tired. However, if you find yourself yawning almost in sync with your sibling, best friend, or partner, the research suggests there may be more to it than just being tired at the same time.

So the next time you catch a yawn from someone you love before you've even registered that they yawned, you can chalk it up to more than coincidence. It might be a small, involuntary sign of just how close that bond really is.