Dogs can distinguish stress from human scent, affecting their cognitive function.
Dogs are influenced by the smell of people stress leading them to make more pessimistic choices, according to research from the University of Bristol’s Veterinary School published in the journal Scientific Reports”.
Scientists studied 18 groups of dog owners by conducting a series of tests with different human odors.
During the tests, dogs between the ages of eight months and ten years were taught that when the food bowl was placed in one place, it contained food, and when it was placed in another place, it was empty. After learning the difference between these bowl locations, a dog approached the location with the treat sooner than the empty location. The researchers then tested how quickly the dog would approach the new bowl locations between the two originals.
A fast approach reflects “optimism”. while in these positions it was an indicator of the presence of food and a positive emotional state slow approach showed negative emotion. Each dog was exposed to either no odor or odor from sweat and breath samples of humans in a stressed or relaxed state.
Researchers have found that the stress odor caused the dogs to approach the bowl’s new location more slowly was closer to the trained location of the empty container. This effect was not observed with the relief odor. According to the researchers, these findings suggest that the stress odor increased the dogs’ judgment that there was no food in this novel location, even in the vicinity of an empty bowl. Researchers make such a hypothesis this “pessimistic” reaction reflects a negative emotional state.
It has also been found that dogs continue to improve their learning of the presence or absence of food in the two bowls they have been trained with, and develop faster when the stress odor is present.
«Dog owners know how to tune into their pets’ emotions, but here we show that even the scent of a stressful, unfamiliar person affects a dog’s emotional state, reward perception, and learning.” notes Nicola Rooney, a lecturer at the University of Bristol’s School of Veterinary Medicine and lead author of the study.