In another experiment, the participants were given the same instructions; however, the researchers also applied electrical currents to the people's scalps, which were meant to stimulate the motor cortex, the part of the brain that controls yawning
is triggered involuntarily when we observe another person yawn -- it is a common form of echophenomena -- the automatic imitation of another's words (echolalia) or actions (echopraxia).
Padala; A Case of Excessive Yawning
With Citalopram; Prim Care Companion J Clin Psychiatry.
Although age was the most important predictor of contagious yawning
, only 8% of the variation in whether or not a participant yawned was explained by their age.
But Elizabeth Cirulli, author of the latest study and assistant professor at Duke University School of Medicine, says: "The lack of association in our study between contagious yawning
and empathy suggests that contagious yawning
is not simply a product of one's capacity for empathy.
Another theory, of course, is that yawning
seems to be contagious.
Researchers used a standard definition of yawning
to distinguish it from non-yawn mouth opening.
Study co-author Nadja Reissland, a psychologist at Durham University, said that they still do not know what importance and function the yawning
of a fetus carries.
In total there were 480 instances where one person yawning
triggered yawns in another within three minutes.
Theory one is that yawning
is a fixed action pattern that may be set off by the stimulus of seeing someone else yawn; theory two, sometimes known as the 'chameleon effect', is that contagious yawning
is caused by an unconscious tendency to mimic the mannerisms of a companion; theory three is that it is caused by a feeling of empathy towards the other yawner.
in humans happens because of the inherent trait of empathy.
It describes yawning
as an ideal model for understanding a transitional behaviour and its relevance in neuroanatomy, neurophysiology, ontogenesis, phylogenies and social cognition.