Consciousness Blog 19 September 2010
"Emotional contagion seems to be a primal instinct that binds us together," said Helt. "Yawning may be part of that." She conducted the study after trying and failing to get her own autistic child to clear his ears on a plane by repeatedly yawning at him.
"The fact that autistic kids don't do it might mean they're really missing out on that unconscious emotional linkage to those around them," says Helt. "The big thing people try to figure out in infant development is how we become humans who understand that humans have minds that are different from ours," she added. "Autistic people never sort of seem to understand that."
Spontaneous yawning begins in the womb at the age of 11 weeks, and continues throughout life. All vertebrates yawn, although yawning contagion has been demonstrated only in humans, dogs and the great apes.
There are multiple theories about the reason for yawning, and why it should be contagious, although it seems obvious that it is a form of communication as well as having some bodily utility in raising altertness and general readiness. Otherwise, why yawn when you are on your own? Specifically, Helt says, it could diffuse stress after a period of being on high alert and spread a feeling of calm through a group. In baboons, at least, yawning involves an aggressive display of teeth. It is easy to believe that among a somnolent group of hunter-gatherers, there would be utility in behaviour that led to a greater degree of alertness.
Whatever the reason
for contagious yawning, at least it is sure that it is a display of empathy,
and there are other contagious behaviours in a group context which employ
the principle of empathy, including laughing, crying and angry aggression.
Such behaviours are entirely involuntary; with the development of the
self and 'conscious' self-awareness in humans come facial behaviours which
are under a mixture of conscious (voluntary) and unconscious (involuntary)
control, and these can also be contagious. Smiling, sadness, surprise
and sympathy are examples of states which we may express entirely 'naturally'
or which we may at least partially construct to suit our conscious inter-personal
agenda at a given moment. In many social (group) situations such states
are contagious within the group, indeed we may deliberately set out to
use them to influence the behaviour of the group.
Read more in Chapter Three of Agent Human by Michael Bell, The Evolution of Social Consciousness in Humans.