We’ve all heard the phrase “animals can smell fear” and a recent study has suggested that horses can indeed pick up on emotions from human sweat. An Italian investigation monitored the heart rate of horses in response to human body odors, and appeared to show that equines displayed different responses to “fear” and “happiness”.
“Our results revealed that human body odors induce sympathetic and parasympathetic changes and stimulate horses emotionally, suggesting inter-species transfer of emotions via body odors,” said the authors of the study, conducted by Dr. Antonio Lanata and colleagues at the University of Pisa. Sterile pads were used to collect sweat from the armpits of human subjects, who were watching 25-minute “fear or happiness-inducing” videos. These were arranged into pooled samples for fearful and happy states.
Seven horses were then recruited for the study, and after baseline ECGs were taken, they were approached in their boxes by an unfamiliar person, who scented their hands in turn with test tube samples of fearful and happy odors, as well as a third “no odor” sample. The horses’ ECG signals were recorded under these conditions and then analyzed. Statistics showed that human fear odor caused an increase in spectral power on both the low frequency and high-frequency bandwidths of the ECG and that happiness and fear elicitation were statistically different in low-frequency peak values.
“The results showed that human chemosignals affect the physiological status of horses as seen by the changes in their autonomic activity,” the study concluded. The research aimed to explore the mechanism by which human emotions could influence equine behavior, particularly the tendency of horses to perform “unexpected reactions” when ridden by a “nervous person”.
