Horses Sense Human Fear Through Scent study

Horses Can Smell Human Fear, Study Finds

Research Shows Fear Is Detected Scent Alone

Horses really can sense your fear. A new study suggests that when a person feels afraid near a horse, the animal can detect the emotion purely scent — a change that can alter both its behaviour and its physiology. The findings were published in the journal PLOS One.

Scientists Investigate Whether Horses Can Smell Emotions

While it is already well established that dogs can smell human stress, researchers at France's National Research Institute for Agriculture, Food and the Environment (INRAE) set out to discover whether horses, long domesticated companions of humans, share this remarkable ability.

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The Scent of Fear

How Sweat Samples Were Collected

To collect scent samples, researchers asked 30 volunteers to wear cotton pads while watching the horror film Sinister, capturing sweat produced during moments of fear. The same participants later wore pads again while viewing uplifting or humorous clips, when they were calm and in a more positive emotional state. This allowed the team to directly compare how horses responded to fear and joy.

Exposure of Horses to Human Scents

The pads were then placed inside specially designed Lycra muzzles worn by 43 female Welsh horses. The animals were randomly divided into three groups:

• One exposed only to fear-related scent
• One exposed to sweat collected during joyful moments
• One control group fitted with scent-free pads

Behavioural and Physiological Changes Observed

The horses were then put through four behavioural tests:

• Grooming
• Responding to a suddenly opening umbrella
• Being approached by a person
• Investigating a novel object

Researchers closely monitored the animals' reactions throughout each test.

Horses React Strongly to Fear-Related Scents

When exposed to fear-related sweat, the horses became noticeably more alert. They startled more easily, fixated longer on unfamiliar objects, showed sharper spikes in heart rate and were less inclined to approach or make contact with a person.

As the animals could not see the volunteers, there were no facial expression or body-language cues involved, suggesting their reactions were driven purely by scent. Although the researchers did not analyze the chemical make-up of the samples, the response points to chemical signals as the trigger.

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What the Findings Reveal About Animal Communication

In their paper, the research team said the results underline the importance of chemosignals in interactions between different species and offer fresh insight into how domestication may have shaped emotional communication.

Improved Animal Welfare Implications

The findings could have far-reaching consequences for animal welfare, suggesting that a handler's emotional state can be passed to a horse through scent alone — even when those emotions are consciously concealed. This insight may reshape approaches to horse training and the way overall equine wellbeing is managed.

Practical Takeaway for Horse Handlers

The researchers added that the practical takeaway is clear: handlers' emotional states matter and these emotions may be transmitted via chemosingnals during everyday human-horse interactions.

Source

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