When you think of man’s best friend, most people think of a dog. But barking friends are not the only animals that can perceive human emotions. French scientists proved that even horses have this ability. They can sense human fear using their sense of smell. Scientists from the University of Tours investigated this ability in horses.
They found that when horses were exposed to odor samples from humans experiencing fear, they reacted significantly more sensitively. They had an increased heart rate and were more restrained when interacting with caregivers than when exposed to odors associated with positive emotions.
Like dogs, horses also recognize chemical signals released in human sweat during emotional states. These chemosignals are created thanks to volatile organic compounds, the composition of which changes during stress or anxiety. Although they are almost imperceptible to humans, animals with a sensitive sense of smell can detect them.
French researchers sampled odors using cotton swabs placed in the armpits of people watching scary or happy videos. They then attached these samples to the nostrils of 43 mares and monitored their behavior in startle tests, encounters with unfamiliar objects, and interactions with humans. Horses exposed to stressful human odors were more easily startled, observed unfamiliar objects longer and approached people less often. Conversely, odors associated with happiness or neutral samples elicited calmer reactions.
“This study shows how closely animals and humans are connected. We can unconsciously transfer our emotions to animals, which has a rather significant effect on their own emotional state.” said Dr. Léa Lansade from the University of Tours.
