Call it the finding that puts the “aw” in yawn—scientists have discovered that people yawn more in response to the yawns of people they care about most.
So-called contagious yawning is a type of psychological effect that happens only in response to seeing, hearing, or reading about yawning.
Though there have been previous hints of a link between contagious yawning and empathy, the new study marks the first time scientists have actually observed the connection.
New statistical models showed that the rate at which people yawned contagiously was highest in response to kin, then friends, then acquaintances, and lastly strangers.
The findings suggest that yawning is a form of empathizing with people experiencing a feeling, which—in the case of yawning—usually means stress, anxiety, boredom, or fatigue.
“This is the important point: By reenacting the mechanism, it’s like you share emotions, so your response is higher because you mirrored each other’s emotions,” said study co-author Ivan Norscia of the Natural History Museum at the University of Pisa in Italy.
By contrast, spontaneous yawning, a purely physiological phenomenon, may occur to cool our brains, according to recent findings.