You just got some bad news. Your dog approaches cautiously and puts his head on your lap, as if to say, "Sorry you're having a bad day."
That kind of canine behavior may be more than a simple coincidence, according to a new study published in the Royal Society journal Biology Letters. Domestic dogs may have the ability to recognize human emotions by processing information from different senses, like sight and sound—something that, until now, has never been observed outside of humans.
To test the cognitive ability of 17 domestic dogs, researchers—a team of animal behavior experts and psychologists from the University of Lincoln, United Kingdom and the University of Sao Paulo, Brazil—used pairings of images (facial expressions) and sounds (voices or barks) that signified positive (happy or playful) and negative (angry or aggressive) emotional expressions in both humans and dogs. To prevent bias, the photos and audio clips were all from unfamiliar dogs or people and were played simultaneously, without any prior training.
The dogs spent significantly more time looking at the facial expressions of both humans and other canines that matched the sound, suggesting that man's best friend uses multi-sensory clues to gauge someone's emotional state.
Despite the small scale of the study, scientists are hopeful that these findings will provide some insight into the long-standing debate about whether dogs can recognize human emotions. "Our study shows that dogs have the ability to integrate two different sources of sensory information into a coherent perception of emotion in both humans and dogs," study co-author Professor Daniel Mills, from the School of Life Sciences at the University of Lincoln, said in a statement. "This cognitive ability has until now only been evidenced in primates and the capacity to do this across species only seen in humans."
Researchers say these emotional abilities may help foster and solidify the bond between humans and their canine counterparts.