When do we first learn to express empathy? That’s a question psychologists have been probing for some time by, among other things, examining when we learn to imitate yawns. Scientists first came to the conclusion that “yawn contagion” — as they call it — was related to human empathy when they found that toddlers didn’t have it. Research suggests kids learn to yawn in response to others beginning at age 4 when they also learn to read emotional cues.

Is it possible that puppies also have to learn that yawns are contagious? A new study published in the journal Animal Cognition suggests yes. Swedish researchers selected 35 ordinary house dogs of various breeds between 4 and 14 months of age and sat them in front of their owners to see whether they would respond to fake yawns — a gaping mouth with no sounds such as inhaling and exhaling of air — and to realistic yawns that seemed convincing.