They can’t talk back and they probably can’t understand the words we say, but that doesn’t mean animals don’t feel what we say to them. In a new study, researchers from the University of Copenhagen found that horses, pigs and wild horses were able to distinguish between positively and negatively charged sounds, including those in human speech, as evidenced by their behavior.
“The results showed that domestic pigs and horses, as well as Asian wild horses, can tell the difference, both when the sounds come from their own species and close relatives, and from human voices,” behavioral biologist Elodie Briefer of the university’s department Biology of Copenhagen in a statement.
Humans are emotional and social creatures by nature. In fact, we are so social that our emotions can sync up with the people we talk to during our interactions. If I’m feeling sad and we’re communicating, you might feel sad too. If I’m smiling and very positive while we’re having a conversation, there’s a good chance the emotion will come over you. This phenomenon is known as emotional contagion or mirror and can be caused by facial expressions, indirect human interactions, and by observing other people’s behavior in direct and indirect interactions.
Part of the reason the researchers embarked on this study was to see if animals can also be affected by emotional transference. The animals in the experiment were private horses, pigs from a research station, as well as wild Przewalski horses and wild boars from zoos in Switzerland and France.
The animals were subjected to animal calls and human voices played from hi-fi hidden speakers. The sounds were played in sequences with a positively or negatively charged sound first, followed by a pause and then sounds of opposite emotions to the original record. To avoid any bias caused by reactions to specific words pets may know, the human voices were recorded by a professional actor who uttered emotionally charged gibberish, conveying joy and amusement (positive), as well as anger and fear (negative), but without a specific meaning to the sentences.
The animals showed signs that they could distinguish between the positively or negatively charged sounds, including the human voices. For example, the animals react faster and more fearfully when they hear a negatively charged voice. In certain situations, they even seemed to reflect the emotion they were being exposed to. The exception was wildboards, which didn’t seem to react differently to the human voices. However, the bears changed their behavior accordingly when exposed to positively or negatively charged animal sounds.
“Should future research projects clearly show that these animals mirror emotions, as this study suggests, it will be very interesting in terms of the history of emotion development and the extent to which animals have an emotional life and level of consciousness,” says Korter.
According to the researchers, their findings suggest that the way they speak and interact with animals can matter a lot, with important implications for their well-being. From an ethical perspective, this means that people who work directly with animals, whether in the zoo, research lab or farm, should try to pay more attention to their language. Conversely, if people want to actively improve the daily lives of animals, they can try to use calmer, more positive language and attitude.
“It means that our voices have a direct impact on the emotional state of animals, which is very interesting from an animal welfare point of view,” “Should future research projects clearly show that these animals reflect emotions, as this study suggests, it will be very interesting in relation to the history of the development of emotions and the extent to which animals have a feeling life and level of consciousness,” said Briefer.
The findings appeared in the journal BMC Biology†