The researchers showed horses a picture of person with a happy or angry facial expression on a screen and played prerecorded human voice praising or scolding from a speaker behind the screen. | Photo: Kosuke Nakamura

Both horses and dogs have long served humans as working animals and companions in sport and leisure, establishing close relationships with “their people.” Researchers know that dogs can relate human facial expressions and voices to perceive human emotions, but it has remained unclear whether horses can do the same. Scientists in Japan, however, have found the answer.

Ayaka Takimoto, PhD, an associate professor at Hokkaido University; graduate student Kosuke Nakamura of the University of Tokyo; and former Professor Toshikazu Hasegawa, PhD, of the University of Tokyo, recently used the expectancy violation method to investigate whether horses cross-modally perceive human emotion by integrating facial expression and voice tone. They also tested whether the familiarity between the horse and the person affected the horse’s perception.

The expectancy violation method has been used to study infant cognitive development. In this study, the researchers showed horses a picture of person with a happy or angry facial expression on a screen and played prerecorded human voice praising or scolding from a speaker behind the screen. Horses experienced both the congruent condition, in which the emotional values of facial expression and voice tone were matched, and the incongruent condition, in which they were not