The next time a canine companion looks worried, it may be because of their humans, according to a recent study.
A new study has discovered that dogs can smell humans' stress, and it seems to have a real effect on them.
For probably 30,000 years, humans and canines have always been close companions, according to anthropological and DNA evidence, which makes sense as to why dogs are able to identify and interpret human emotion.
Dogs have evolved to read verbal and visual cues from their owners, and previous findings have shown that with their acute sense of smell, they can even detect the odor of stress in human sweat, says Live Science.
The findings, published Monday in Scientific Reports, were conducted by scientists at the University of Bristol in England.
Researchers recruited 18 dogs of varying breeds, along with their owners and eleven volunteers who had little experience with canines, and put them through a stress test involving public speaking and arithmetic while samples of their underarm sweat were gathered on pieces of cloth.
Zoe Parr-Cortes, lead study author and Ph.D. student at Bristol Veterinary School at the University of Bristol, said that the results imply that when dogs are around stressed individuals, they're more pessimistic about unstable situations, whereas proximity to relaxed odors does not have this effect.
"For thousands of years, dogs have learned to live with us, and a lot of their evolution has been alongside us. Both humans and dogs are social animals, and there's an emotional contagion between us," she says.
"Being able to sense stress from another member of the pack was likely beneficial because it alerted them of a threat that another member of the group had already detected," added Parr-Cortes.
Katherine A. Houpt, a professor emeritus of behavioral medicine at Cornell University's College of Veterinary Medicine who was not involved in the study, explains that the research shows that dogs possess empathy based on smell in addition to visual and verbal cues.
When you're stressed, it translates into behaviors that a dog doesn't usually display.
"If the dogs are responding to more mild stress like this, I'd be interested to see how they responded to something more serious like an impending tornado, losing your job, or failing a test," Houpt says.
"One would expect the dog to be even more attuned to an actual threat."
