Vicky Arias, FISM News
Dogs determine a person’s state of mind, in part, based on their scent, according to a new study.
The study, published in September in a Public Library of Science journal, reveals that dogs can smell stress in humans.
When humans experience stress or anxiety, chemicals change in their bodies. In their study, researchers in Ireland and England illustrated that dogs are capable of detecting these chemical changes and reacting to them.
According to the study, “the principal physiological process associated with anxiety, panic attacks, and PTSD is the stress response” in addition to a chemical profile that fluctuates up and down depending on whether or not a person is calm or stressed.
The team conducting the study first trained four dogs to recognize various stress chemicals released by humans.
Researchers then took breath and sweat samples of 36 human subjects when they were calm, to obtain a baseline, and again after they were asked to solve a stressful task, specifically a difficult math problem. In total, researchers conducted 720 trials.
During the trials, the trained dogs were presented the baseline scent and the stressed scent of a specific person. The animals performed exceptionally well. According to Clara Wilson, one of the principal researchers on the team, “dogs were given one person’s relaxed and stressed samples, taken only four minutes apart. In 94% of 720 trials, the dogs were able to correctly alert [researchers] to the stress sample.”
#Dogs can sniff out the scent of stress from human sweat and breath, say @ClaraHBWilson of @QUBelfast and colleagues.
🔎 @PLOSONE paper: https://t.co/Hbg9Gk9XcP
📰 @Gizmodo article: https://t.co/OQgY7zNh1r
📰 @Independent article: https://t.co/DEbkGxvNnL— PLOS (@PLOS) September 30, 2022
The researchers found that the “dogs were able to discriminate, with a high degree of accuracy, between human breath and sweat samples taken at baseline and when experiencing psychological stress. [The] results suggest that there is a [chemical] profile associated with acute psychological stress that is detectable by trained dogs.”
Research into dog-to-human stress reactions could strengthen the service-dog industry exponentially. According to the American Kennel Club, service dogs are used by 80 million Americans. The Americans with Disabilities Act describes service dogs as animals “that are individually trained to do work or perform tasks for people with disabilities. Examples of such work or tasks include…calming a person with Post Traumatic Stress Disorder (PTSD) during an anxiety attack.”
Service dogs receive training in many areas, like cancer detection, alerting diabetics of dangerous blood sugar levels, and sniffing out drugs. Some of these dogs also aid in psychiatric care.
Currently, psychiatric service dogs are trained to interrupt nightmares, turn on lights in dark rooms to reduce stress-inducing anxiety, and “[alert] a handler before a panic attack or other episode occurs,” according to the American Kennel Club.
Air Force veteran Stacy Pearsall explained that her service dog helped with her PTSD.
“If I’m thrashing in my sleep from a PTSD nightmare, he’ll nudge me awake or pull off the covers and put his head on my lap to be petted until my heart rate comes down….I used to feel like a burden to loved ones, but now, I feel the shackles have been taken off.”
The scent-study researchers concluded that “it is possible that an odor component may be useful as a training aid for service dogs tasked with responding to acute stress responses in their owner. More broadly, establishing that dogs can detect an odor associated with stress sheds light on the human-dog relationship and adds to our understanding of how dogs may interpret, and interact with, human psychological states.”