THURSDAY, Aug. 8 (HealthDay News) -- Yawn in the presence of
your pooch and they're likely to yawn right back at you, a new
The research, a series of carefully controlled experiments with
25 dogs of different breeds, confirms that dogs are more likely to
"catch" their owner's yawns than a stranger's and more likely to
respond to real yawns as opposed to fake ones. Fake yawns involve
opening and closing the mouth in the movement of a yawn without
making any sound.
Researchers also strapped heart rate monitors to the dogs to
make sure they weren't yawning because they were stressed or
anxious. They weren't.
"We tried to create a comfortable atmosphere in doing the experiment, and sometimes it was so comfortable for them that they fell asleep," said study author Teresa Romero, a research fellow in the department of cognitive and behavioral science at the University of Tokyo.
The study was published online on Aug. 7 in the journal
Although copying a yawn may not sound like such an impressive
trick, scientists think it's a sign of something important -- the
ability to empathize and bond with others.
Previous studies have shown, for example, that people who score
higher on measures of empathy are more likely to return yawns than
people who aren't as empathetic. And the ability to yawn
contagiously appears to develop with age.
"Several studies have shown that children don't begin to show contagious yawning until around 4 years of age, and only reach adult levels around 12 years of age," said Elainie Madsen, a comparative psychologist at Lund University in Sweden, who has studied contagious yawning.
In the animal kingdom, contagious yawning appears to be a rare
talent. Certain apes, such as chimpanzees and bonobos, which are
some of the closest evolutionary relatives to humans, catch each
other's yawns. Beyond apes, one species of bird appears to be able
to yawn contagiously, and several recent studies have suggested
Canis familiaris, also known as man's best friend, can do
One thing researchers haven't figured out is why dogs yawn along
"There are multiple hypotheses, but the empathy hypothesis is the one that has received most attention over the last few years," Madsen said. "I think the evidence in support for it is accumulating."
She said that at a basic level, contagious yawning probably has
something to do with group coordination and synchronizing group
As happened in the new study, Madsen's study of contagious
yawning in puppies often lulled the dogs to sleep. She doesn't
think that's an accident. "[The dogs] internalized the emotion that
yawning reflects, and basically coordinated their behavior to that
of the yawner," she said.
Dogs live in packs, and Madsen expects that all animals that
live in groups may demonstrate the ability to catch yawns.However,
researchers say the jury is still out on whether cats care that
their owners are tired.
"I think it would be very hard to study contagious yawning between humans and cats," Romero said. "They don't pay very much attention to us."
For more insights into animal behavior, head to the
Animal Behavior Clinic at Tufts University.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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