Along the line, we evolved with certain animals and decided to keep their use but also their ability to connect with us. This is certainly the reason humans have bonded so closely with dogs and cats. As it turns out, this is the case with livestock as well.
A recent study from the University of Copenhagen found that pigs and domesticated and wild horses can tell if human speech is positive or negative.
Researchers played recordings of human voice actors and animal noises from hidden speakers. The sounds the actors made weren’t words but gibberish in a positive or negative tone to filter out any animals’ familiarity with taught words. The animals were domesticated horses, research pigs, and wild Asian horses.
“The results showed that domesticated pigs and horses, as well as Asian wild horses, can tell the difference, both when the sounds come from their own species and near relatives, as well as from human voices,” said behavioral biologist Elodie Briefer of the University of Copenhagen’s biology department.
The results are broken into three theories as to why these animals can pick up on our emotions and the emotions of their fellow species.
How do animals understand humans?
Phylogeny explains that this could be because the particular evolution of each species with a common ancestry can perceive and interpret each other’s sounds because of their shared biology. Domestication explains that close contact and experience with humans have increased the species’ ability to interpret human emotions and communication. Familiarity states that the involved animals could have learned human emotion and certain tones through personal experience with humans.
“Our results show that these animals are affected by the emotions we charge our voices with when we speak to or are around them. They react more strongly—generally faster—when they are met with a negatively charged voice, compared to having a positively charged voice played to them first. In certain situations, they even seem to mirror the emotion to which they are exposed,” says Briefer.
These findings can be used in the future to better determine the wellbeing and proper care of animals.
Source Study: BMC Biology — Cross-species discrimination of vocal expression of emotional valence by Equidae and Suidae | BMC Biology | Full Text (biomedcentral.com)