Smells like mean spirit.
A new study published last week in Scientific Reports cautioned dog owners that the ills of humanity are depressing pets, too. The research found that dogs can smell stress on humans and it’s hurting their mood.
Dogs and humans have been companions for 30,000 years, which is a long enough time to become emotionally co-regulating cohabitants on a genetic level. Previous research has shown that dogs are apt at reading verbal and visual cues as well as sniffing out physical and mental illnesses in people.
Now researchers can add human stress to the list of canines’ super scent skills.
“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,” said Zoe Parr-Cortes, lead study author and a Ph.D. student at Bristol Veterinary School at the University of Bristol, per LiveScience.
Researchers recruited 18 dogs along with 11 human volunteers with little dog experience to be the demonstrators of human stress — ensuring the pets and people had no familiarity prior to the experiment. After completing a battery of stress-inducing, and then relieving, tests, sweat samples were collected from each volunteer.
Based on tests to tempt dogs into swiping snacks from pet food bowls, scientists found that the smell of stressed-out sweat often threw dogs off the trail of treats.
The results implied that dogs expected more pessimistic outcomes when following the scent of stress.
“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,” said Parr-Cortes.