Humans and dogs can form incredible bonds. Some people even believe that their canine companions can understand their emotions. Well, a new study suggests that this could be true. Scientists at Queen's University Belfast in Ireland conducted an experiment with four dogs and 36 humans, and they found that dogs were able to distinguish between people's baseline scent from their stressed odor.
For the first part of this study, scientists collected two sweat and breath samples from the human volunteers. One reflected their normal state and the other indicated them in a period of stress—which was triggered by having the candidates solve a difficult math problem. Afterward, the conductors of the experiment had the dogs sniff out the stressed samples from the collection, finding that they were able to detect the correct sample with a 93.5% accuracy rate.
“The take-home message of this study is that our bodies’ psychological stress response changes the smell of our breath and sweat and that dogs can detect this change,” Clara Wilson, a Ph.D. student in the School of Psychology at Queen's University, said. The evidence from this study has potential implications for the way service dogs are trained. “Knowing that there is a detectable odor component to stress,” she continues, “may raise discussion into the value of olfactory-based training (e.g., taking samples from a person when relaxed and experiencing stress) and positively reinforcing the dog to attend or perform attention-seeking behaviors in response to this odor.”
You can read more about the research in the PLOS ONE journal.