It is a known fact that animals can read human emotions, and now there is scientific base to ascertain that. Horses can read human facial expressions and distinguish between happy and angry faces, researchers have found for the first time.
The results of a study presenting the first evidence of horses' abilities to spontaneously discriminate between happy and angry human facial expressions were published in the journal Biology Letters Wednesday.
Psychologists at the School of Psychology, University of Sussex, studied 28 horses selected from stables in Sussex and Surrey between April 2014 and February 2015.
They monitored how these horses reacted to seeing photographs of positive versus negative human facial expressions. When viewing angry faces, horses looked more with their left eye, a behavior associated with perceiving negative stimuli. Their heart rate also increased more quickly and they showed more stress-related behaviors.
This response indicates that the horses had a functionally relevant understanding of the angry faces they were seeing, the study says. The effect of facial expressions on heart rate has not been seen before in interactions between animals and humans.
A tendency for viewing negative human facial expressions with the left eye specifically have been documented previously only in dogs.
Research shows that many species view negative events with their left eye due to the right brain hemisphere's specialization for processing threatening stimuli (information from the left eye is processed in the right hemisphere). It's interesting to note that the horses had a strong reaction to the negative expressions but less so to the positive. This may be because it is particularly important for animals to recognize threats in their environment. In this context, recognizing angry faces may act as a warning system, allowing horses to anticipate negative human behavior such as rough handling, Amy Smith, a doctoral student at the University of Sussex who co-led the research, said.
"There are several possible explanations for our findings. Horses may have adapted an ancestral ability for reading emotional cues in other horses to respond appropriately to human facial expressions during their co-evolution," according to Professor Karen McComb, a co-lead author of the research.
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