It's a common situation: the person next to you yawns, forcing you to stretch open your mouth and suck in a great gulp of air. This happens, of course, because yawning is contagious. But new research shows that women are more susceptible to catching a yawn than men, writes Laurel Hamers for Science.
Italian researchers sneakily watched more than 4,000 yawns in the real world over five years and found that 54 percent of the time women yawned after they saw someone else yawn. Men only yawned in copycat about 41 percent of the time, the team reports in Royal Society Open Science.
The difference didn't arise because women are sleepier than men: Both groups showed similar rates of "spontaneous" yawns, or yawns that didn't follow anyone else's yawn. The researchers also noted that social bonds are important in how contagious a yawn is—friends and relatives are more likely to elicit sympathetic yawns than acquaintances are.
“The degree of social bonding between individual[s] is important for contagious yawning, but so is gender," says one of the study researchers, Elisabetta Palagi of the University of Pisa, reports Steve Connor for The Independent. "These two variables interact with one another to influence whether someone is likely to take part in contagious yawning."
Because of results like this, researchers think that yawning might be a measure of how empathetic people are. Other animals that create social bonds, such as wolves, tend to show contagious yawning. People with psychopathic traits are less likely to catch a yawn, perhaps because of a lack of emotional connection with those around them.
But piecing together the whole picture is tricky: Some researchers suggested that children with autism don't catch yawns because of some type of empathy deficit, but careful follow-up shows that those children are just missing the facial cues that lead to a contagious yawn. The trouble isn't with the kids' ability to empathize but in their tendency to avoid eye contact.
Still, other research suggests that women do empathize with others more than men. Whether that's because of social training or a biological difference isn't clear. But the difference does appear to manifest in how catching a contagious yawn really is.