Human Ability to Determine Affective States in Domestic Horse Whinnies

Abstract

Horses use whinnies as a communication tool that potentially indicates positive or negative situations reflective of their felt experience. Being able to interpret the emotional state of horses allows humans to respond appropriately to mitigate a negative situation or repeat or enhance a positive situation. This study investigated whether humans can accurately categorize positive and negative whinnies from the domestic horse according to known positive and negative situations validated by behavioral indicators. Using an online survey, participants (n = 309) were asked to categorize 32 horse whinny audio samples based on whether they believed the vocalization was positive or negative and to rate the horse’s arousal level from 1 (calm) to 10 (highly excited). Participants also provided demographic information (age, gender, geographical location, horse experience). Humans were able to correctly categorize the emotional valence of domestic horse vocalizations as positive or negative 64.4% of the time (p < 0.0001). Female participants significantly outperformed male participants (p = 0.0307) in this ability. Age (p = 0.0979), level of horse experience (p = 0.3228), and geographical location (p = 0.0834) did not play a role in an individual’s ability to correctly classify emotional valence, but arousal levels were more likely to be rated higher by older people (p < 0.0001) and females (p = 0.0036) than younger people or males. Positive and negative vocalizations may be indicative of the horse’s emotional state; correct interpretation by humans facilitates an appropriate response to varying situations in training, housing, and husbandry practices.