A new study suggests that dogs can smell stress in humans, which can affect their emotions and decision-making processes, leading to negative decisions.
Previous studies have shown that dogs can indeed smell stress in humans, but how this affects them has yet to be studied.
The published research Scientific Reports The study, conducted on July 22, used odor samples from a variety of people during stressful and relaxing activities and had dogs sniff them to see how they reacted to the stressful smells.
“This is a very interesting study,” said Dr Zoe Per-Cortes, a veterinarian and PhD student at Bristol Veterinary School and lead author of the study. WLIW-FM, “Some people have looked at whether dogs can actually detect differences in smell, and they can. But no one has actually looked at how it affects a dog’s emotions.”
Subjects underwent a stress test and were then given time to relax, during which time smell samples were collected from cloths placed under their armpits.
Eighteen dogs also underwent their own test: They were trained to learn that a food bowl on one side of a room always contained a food reward (called the “positive” location in the study), and the other side was always empty (called the “negative” location).
As time passed, as expected, the dogs began to approach the bowl of food.
The researchers then removed the two bowls from each location and created an “ambiguous” location in the middle.
The dog’s owner then opened the jar using a rag containing a scent sample and let the dog sniff it before placing the bowl in front of it.
“Do they approach the bowl quickly, optimistic that there will be a food reward in it, or do they approach more slowly, pessimistic that there may not be any food in it?” “They’re just like dogs,” Per Cortez said of the dogs.
The researchers tested the stressful and relaxing odor samples multiple times, each in different orders.
The experiment showed that the relaxing smell had little effect, but the dogs who smelled the stressful smell were more hesitant to approach the bowl in an ambiguous location and were very pessimistic about whether the bowl contained food.
Per Cortés explains: “This is basically the smell of stress. [dogs] They are less likely to react to ambiguity, and may be less likely to take risks if they believe they will be disappointed.”
The researchers concluded that these findings may suggest that human scent can influence how dogs perceive risks and rewards.
Molly Byrne, a doctoral student studying comparative cognition at Boston University who was not involved in the study, agreed and said she was impressed by the new findings.
She says dogs think that if their owner is in a bad mood, they won’t get a treat, which makes a lot of sense. “If your owner is really stressed when they’re training you, they probably aren’t giving you as many treats.”
“These findings highlight the need to consider olfactory aspects of dog training and working environments.” the researchers wrote.
