It is nothing new that people tell you to be calm around animals that you are afraid of because they can smell fear. However, a lot of people dismissed this as more of an “old wives tale” than fact. The idea was your demeanor changes when you are scared, thus giving visual signals to those animals, more than an actual smell. The most common two animal groups that this theory exists for, are horses and dogs. However, research now suggests that it is a fact that they can actually smell fear.
The study took humans and showed them videos that either made them happy or scared and then took swabs from the seat in their armpits. In the test, they let horses smell three swabs, those of the scared and happy people, but also a clean control swab. While checking the horse’s heart rate with an ECG, they noticed that the change was obvious when compared to the baseline ECG. Horses can smell fear and happiness, and their biological systems change, too.