It may be a form of social bonding. Children don’t develop this behaviour until they are around 4 years old. A child with autism is half as likely to mimic a yawn and if the case is severe, most likely will never respond to a yawn.
A clinical psychology graduate student at the University of Connecticut, Molly Helt, says that “emotional contagion seems to be a primal instinct that binds us together and yawning may be a part of that.” She became interested in this when she tried to get her autistic son to clear his ears on an airplane. She continually yawned in front of him hoping that he would yawn back. He did not.
She believes that this could mean autistic children are missing out on the “unconscious emotional linkage to those around them.”
Fetuses begin yawning in the womb as early as 11 weeks after conception, says Robert Provine, a developmental neuroscientist at the University of Maryland, Baltimore County.
Scientists cannot explain why yawning continues throughout life. Studies do not show that yawning helps bring in more oxygen. In fact, all vertebrates yawn, including snakes and lizards.
Contagious yawning only occurs with humans and chimpanzees and possibly dogs.
The theory is that contagious yawning is a shared experience that promotes social bonding. It might diffuse stress after a peirod of being on high alert and spread calm througout a group.
To determine when in life the behaviour develops, Helt read a story to 120 children, ages 1-6. The children were grouped by age. All the one- year- olds heard one story, all the two -year -olds heard another story and so on. There were 20 children in each group.
During each 10 minute story, Helt yawned on purpose every 90 seconds. A camera recorded whether the children were watching her and if they yawned, too. The experiment was repeated with 28 autistic children ages 6-15.
None of the healthy one-year-olds yawned. Only one of the two-year-olds yawned back. Two of the three-year-olds yawned back. In the group of 4 year-olds, 9 out or 20 children yawned back. The same rate occurred in the older groups.
Between 40-60% of healthy adults yawns after seeing someone yawn, thing about yawning or read the word “yawn”.
In the autistic children groups, only one-half of the children with mild autism yawned back. Kids with the most severe diagnosis never yawned back.
Robert Provine thinks yawning is a big deal because it is ancient and deep and is a “primal social bonding process”. He believes it is the “roots of empathy”.
I must fall into the 40-60%of adults who yawn after reading the word “yawn” because I have been yawning privately since I began writing this blog.