Study leader Stephen Jackson, professor of cognitive neuroscience at Nottingham University, said: 'This contagion effect is highly individual, with some people yawning 30 times in our 10-minute session and some not at all.
Ever wonder why it's impossible not to yawn when you see someone else doing it?
To test out their theory, the team then stimulated the motor cortex through TMS and found that it would artificially increase participant's propensity for contagious yawning.
Next time you try to stifle a yawn, it might be worth discarding polite etiquette by letting your mouth gape for as long as you need because it could help to reveal how smart you are.More news: Japan's factories sustain solid growth in August as orders quicken: PMI
The researchers found that the participants were only partially successful in resisting yawning: Fewer "full yawns" were observed, but the number of "stifled yawns" increased, according to the study.
"Contagious yawning, in which yawning is triggered involuntarily when we observe another person yawn, is a common form of echophenomena - the automatic imitation of another's words (echolalia) or actions (echopraxia)", the study said. It turns out scientists even have a name for that - contagious yawning, and it happens for around for 60% to 70% of people. They recruited 36 adult participants and showed them video clips of other people yawning, instructing them to either try and stifle the yawn or let it rip. Nonetheless, urge-to-yawn estimates increased significantly when participants were instructed to resist yawning.
It is not just the humans who have a propensity for contagious yawning - chimpanzees and dogs do it too. All the while, the researchers used transcranial magnetic stimulation (TMS) to poke targeted areas of their brains into action, in an attempt to gauge which areas make yawns contagious. When the researchers applied electrical currents to the motor cortex in their experiments, the urge to yawn among the participants increased. While the cause of this brain phenomenon is unknown, researchers believe it's tied to neurological conditions like Tourette's, autism and epilepsy, and understanding echophenomena might provide clues for treatment.
Georgina Jackson, Professor of Cognitive Neuropsychology in the Institute of Mental Health, commented: "In Tourettes if we could reduce the excitability we might reduce the ticks and that's what we are working on".
"If we can understand how alterations in cortical excitability give rise to neural disorders we can potentially reverse them".