It’s not just microbes that are infectious; emotions, moods, and of course even yawns can spread between us. While the reason behind the contagious nature of the latter is still largely up for debate, a new study has added evidence to one leading theory. According to the results, women are more likely to catch a yawn from others than men. Given that females are generally considered the more empathetic gender, the findings lend weight to the idea that contagious yawning is an empathy-based phenomenon.
Lasting around six seconds and often accompanied with a less-than-attractive facial expression, yawns have been implicated in various different physiological processes, like our sleep-wake cycles and body temperature regulation. Regardless of the driver, it’s clear that yawning can be contagious, something also observed in various other mammals and even budgies.
But interestingly, not all individuals show equal susceptibility to yawning. Studies have shown that up to 60 percent of people don’t yawn in response to others under laboratory settings, and those with empathy disorders or social impairments, such as schizophrenic or autistic individuals, are less likely to show contagious yawning. In addition, research has shown that susceptibility is dependent on the social relationship with the yawner.
These observations do seem to suggest that catching a yawn may be related to empathy – the ability to understand and share the feelings or condition of another individual. If that is indeed the case, then we would expect women to show greater susceptibility than men. That’s because a large body of evidence indicates that women are the more empathetic sex, likely because of their roles in child rearing and cohesion of social groups.
Ahh, that feels good. herjua/Shutterstock
To explore whether sex differences are indeed apparent, researchers from the University of Pisa spent almost five years gathering yawn data in a variety of natural settings, from office environments to the dinner table. None of the individuals recorded were aware they were being watched, although they were all known by the researchers, meaning their age and relationship to others could be noted.
To make sure they weren’t mistaking a spontaneous yawn for one caught from another, yawn responses were only recorded if they took place within a three-minute window after the trigger yawn. Similarly, yawns were only noted as spontaneous if no one else had yawned around them for the previous five minutes.
Described in Royal Society Open Science, the frequency of spontaneous yawning was similar for men and women, but women were more likely to respond with a yawn than men. In addition, contagious yawning was more common in those with closer social relationships, such as friends or family members, compared to acquaintances. The latter is also observed in certain non-human primates, like chimpanzees, who also show greater yawn rates if the trigger is a group member rather an outsider. Like the observed sex differences, this also supports the notion that yawn contagion has its roots in empathy, since animals are more likely to behave empathetically if they have a bond with the other individual.
"At the group level, yawn contagion is biased by social factors," lead author Ivan Norscia told IFLScience. "So the variation in yawn contagion observed within social groups may be related to the role that females and males have in that social group. For example, using yawning videos, a study found male chimpanzees responded more to the yawns of other males than of females." Since males are dominant in chimpanzee societies, the authors argue, male signals are likely more relevant to other group members than those from females.
Alongside supporting the empathy hypothesis, the authors highlight the implications of their research. “The ability to preconsciously decode and replicate the emotions of others… may allow women to respond with more appropriate behaviors toward others and be more successful in forming enduring alliances,” they conclude.