We are all aware of the changes that occur in our bodies when influenced by high stress levels; our heart beats faster, our blood pressure rises and our breath shortens. But most of all, our nervous system is inclined to emit stress hormones or odours that are detected as chemical signals.
Dogs were able to detect stress with 93.75% accuracy
Given dogs early domestication with humans and their successful training as PTSD service dogs where they support humans by detecting physiological changes, it has been hypothesized that dogs have developed the ability to detect the chemical signals humans give out.
A recent study at Queen's University Belfast put this theory to the test!
Researchers took breath and sweat samples from human participants. To induce high-levels of stress (just like those experienced when having to cram for that dreaded exam) samples were collected before and after a fast-pace arithmetic task. The doggy scientists then trained up four of their super sniffers to alert when presented with a sample that came from a stressed human.
Each dog was then presented with multiple samples from both before and after the stress inducing task. And what success they had! The nifty noses were able to detect the stressed samples with a 93.75% accuracy.
Doggy scientists were trained to alert when presented with stressed samples
Whilst this study does not suggest dogs are able to understand that a human is stressed or the emotions a human is experiencing, it does demonstrate a dogs ability to discern between stressed and unstressed samples.
In addition to the many characteristics that dogs offer, this discovery brings a new awareness to human-dog relationships and their applications as anxiety or PTSD service dogs. So next time you're stressing over that overdue essay, or organizing your summer getaway, chances are that your furry friend already knows.
DOI: https://doi.org/10.1371/journal.pone.0274143
