Yawning is known to be contagious in humans but now scientists have shown that pet dogs can catch a yawn, too.
The copying activity suggests that canines are capable of empathising with people, say the researchers who recorded dogs' behaviour in lab tests.
Until now, only humans and their close primate relatives were thought to find yawning contagious.
The team - from Birkbeck College, University of London - reports its findings in Biology Letters.
Yawning, although sometimes a response to extreme stress, is more often a sign of tiredness; but the reason for why yawning is catching is not fully understood.
Human cues
There is evidence that autistic individuals are less inclined to yawn into response to another human yawning, suggesting that contagious yawning betrays an ability to empathise, explained Birbeck's Dr Atsushi Senju.
Dr Senju and his team wondered whether dogs - that are very skilled at reading human social cues - could read the human yawn signal, and set out to test the yawning capabilities of 29 canines.
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