Just thinking about yawning makes us yawn, and now scientists think they've figured out why yawning is so contagious.
In a new study published in Current Biology, researchers at the University of Nottingham say the reason we reciprocate yawns may be rooted in primitive brain reflexes, and the more we learn about this part of the brain (which controls motor functions), the more we can help treat disorders such as Tourette syndrome.
The automatic imitation of someone else's words or actions, such as yawns, happen because of a trait called echophenomena, and humans aren't the only ones who involuntarily yawn when they see other people do it — chimpanzees and dogs do it too.
To figure out where the roots of this type of echophenomena are located, the researchers examined 36 adults as they watched videos of people yawning. The participants were told to either try to stop themselves from yawning or just yawn naturally when they felt like it.
Based on these examinations, the researchers found that it's hard to resist yawning when you see someone yawn, and that urge only gets stronger when you're told not to yawn.
"We suggest that these findings may be particularly important in understanding further the association between motor excitability and the occurrence of echophenomena in a wide range of clinical conditions... such as epilepsy, dementia, autism and Tourette syndrome," said study leader Stephen Jackson.
It's hard to resist yawning when you see someone yawn, and that urge only gets stronger when you're told not to yawn
The researchers also found applying electrical stimulation drove the necessity to yawn, which could help in the treatment of some disorders.
"This research has shown that the 'urge' is increased by trying to stop yourself. Using electrical stimulation, we were able to increase excitability and in doing so increase the propensity for contagious yawning," said Georgina Jackson, a professor of cognitive neuropsychology.
This research has shown that the 'urge' is increased by trying to stop yourself.
"In Tourette's, if we could reduce the excitability we might reduce the tics, and that's what we are working on," she said in a news release.
But if you're not the type of person to "catch" a yawn, we're gonna take a few steps back from you because you might be a psychopath.
Research from 2015 found that psychopaths may be more immune to contagious yawning than the rest of us.
According to a study, the reason why psychopaths don't seem to "catch" yawns is because contagious yawning is a sign of empathy, a trait that psychopaths lack.
"Psychopaths are partly defined by lack of empathy and compassionate understanding of the feelings of others," Brian Rundle, a doctoral researcher at the university and one of the study's authors, told HuffPost. "The fact that they aren't able to contagious yawn suggests that the mechanics involved in the empathy process aren't functioning normally."
Also on HuffPost: