Horses Can Sense Your Fear, Bizarre Sweating Study Finds

Horses that were presented with cotton pads soaked in the sweat of a frightened human showed more signs of fear themselves.

By Marta Hill edited by Claire Cameron

Horses can sense human fear and it changes their behavior.

This is the result of a rather unusual experiment which consisted of making horses smell material soaked in human sweat and observe what they did next. The conclusions were published today In PLOS One.

Horses exposed to sweat samples People who had a frightening experience seemed more frightened themselves: the animals were easily startled, hesitated to approach researchers, and became less likely to interact with unfamiliar objects.

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“Our emotions are central when we interact with horses,” says Plotine Jardat, lead author of the study and researcher on horse behavior and well-being at France’s National Institute for Research on Agriculture, Food and the Environment. “If your horse isn’t cooperating with an exercise you suggest, perhaps trying it another day, when you feel differently, can be a game-changer.”

Researchers already knew that horses can respond to emotional signals from humans, including facial expressions And tones of voice. But the new study went further by examining whether horses could sense different emotions emanating from humans without these visual or oral cues.

In the experiment, a group of people wearing cotton pads under their armpits watched video clips intended to produce a feeling of joy; these included the dance scene in the film Singing in the rain and the song “We Go Together” from the film Fat. The researchers then asked the participants, armed with new cotton pads, to watch 20 minutes of the horror film. Sinister to stimulate fear.

The sweat samples were then stapled into a custom muzzle that the horses could wear. To limit the stress of each test horse, a “public horse” served as a control for the behavior tests.

The researchers first measured the frequency with which a trial horse would interact with the experimenter based on what it smelled, both during grooming and when the experimenter stood slightly away from the animal. Horses that smelled the fear samples touched the experimenter less than those in a control group or those that smelled the happy sweat samples.

The team then tested the horses’ responsiveness by opening an umbrella near a bucket of food. Once again, horses that smelled of fear sweat showed a different reaction than those that smelled something else. Their physical reactions to surprise were stronger and their heart rates were higher.

The last test consisted of presenting the horses with a new object: a sort of sculpture, made of linoleum, plastic and string. The researchers recorded how often a horse looked at the object and how often the animal touched it. Horses in the fear group touched the new object less often and looked at it from a distance more than their peers.

Taken together, the horses’ reactions indicate that they can sense fear through scent alone, the researchers conclude. What the study doesn’t answer is why horses can apparently do this: this ability could be the result of domestication, or it could come from an underlying characteristic of mammals. Either way, maybe don’t go horseback riding immediately after watching a horror movie.