Horses can smell fear in people.

The study shows that horses can distinguish human emotions by smell alone.

To determine whether horses react to cold sweats in humans, a team led by scientist Agnieszka Sabiniewicza from the University of Warsaw collected odor samples from 10 people. Sterile cotton pads were placed under people's arms while they were watching a horror film, and while being shown a funny cartoon. During the experiment, the researchers presented the pads to 21 test horses. To rule out individual differences, they combined odor samples from four anxious and four happy people. There was also a control round with odorless pads. While the horses sniffed the scents, two people were present each time - one known to the horse and one unknown. The people behaved calmly and neutrally.

The research team found that horses showed different behaviors in response to the odors.

When the horses smelled a "happy" smell, it seemed to have a calming effect. When the scent of fear and the odorless control pads were detected, the horses raised their heads much more frequently and for longer. In addition, when the horses smelled fear, they tended to touch the person they knew more often and for longer than when they smelled "happiness." Depending on the smell presented, the length of time the horses had their ears also flattened varied.

The researchers concluded that the presentation of human body odor from humans in different emotional states is enough to induce different behavioral responses in the horse.

The fact that horses can smell fear underlines how important human feelings are for horse training and everyday dealings.

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You can read the study here:

Olfactory-based interspecific recognition of human emotions: Horses (Equus ferus caballus) can recognize fear and happiness body odour from humans (Homo sapiens)

Agnieszka Sabiniewicza, Karolina Tarnowska, Robert Świątek, Piotr Sorokowski, Matthias Laska

Applied Animal Behaviour Science (2020) vol 230; 105072

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