If you want to know how your cat or dog is feeling, just listen. Happy kittens purr, angry kittens growl. But can we extend the same understanding to creatures that do not share the same home: pigs or even wild animals?
A new study shows we can to some extent. A survey of more than 1,000 people from around the world reveals that most people can capture the excitement of an animal, but not necessarily positive or negative emotions.
“It’s an exciting concept: Even though we’re so different, there are still some commonalities in the voiceovers,” says Jenna Congdon, an ethologist at Concordia University in Edmonton who was not involved in the study. “We don’t speak the same language, but we can understand very basic things.”
An animal’s emotional sounds have two parts. The first is arousal, where something exciting changes the duration, amplitude, or frequency of a particular sound. When shaken, for example, the standard moo of a cow with increasing amplitude becomes a bellows. The second is valency, which is the positive or negative intonation of a particular sound. For example, the high-pitched squeal of a frightened pig is very different from the loud growl of a happy pig.
People are proficient at perceiving other people’s arousal and worth, even if they come from a very different culture or speak another language. But scientists aren’t sure if we can do the same for animals.
So, in the new study, researchers at the University of Copenhagen analyzed records of four domesticated mammals (pigs, horses, goats, and cows) and their two wild relatives (wild boars and Przewalski’s horses, a critically endangered wild horse endemic to Mongolia). they got it. . Recordings were made while the animals were experiencing certain emotions that were categorized as positive, such as a shrill coriander from a horse preparing to eat, or negative, such as a hungry horse’s throat groan. The trial also included audio excerpts of recorded human actors speaking nonsense in an angry, fearful or cheerful tone.
The team then sent the files and a questionnaire to volunteers who responded to an ad circulating on social media, magazines and a TV show. Respondents came from 48 different countries and had the option to participate in the survey in eight different languages, including Italian, Dutch and Hebrew. For each question, they compared two short audio tracks of a particular genre and decided which clip represented high or low arousal, and which vocalization represented a positive or negative emotion.
Volunteers were able to accurately distinguish arousal in pigs, horses, and goats more than half the time.the team is reporting today inside Royal Society Open Science. Emotional valence scores were more variable. Survey respondents were able to distinguish positive sounds from negative sounds (accurately identifying positive vocalizations 56% to 68% of the time) in humans, goats, horses, pigs, and wild boars at an above-average clip, but had difficulty distinguishing between emotions from cows and wild horses. was voiced by (only between 33% and 47% accurate detection).
“Humans are very good at recognizing the sounds of horses and very bad at recognizing others, such as cattle and Przewalski’s horses,” says study author Elodie Briefer, a behavioral ecologist in Copenhagen.
A participant’s gender had little effect on the accuracy of their answers. Instead, younger volunteers and those with experience working with animals were better at grasping both arousal and emotional value.
The study suggests that it may be evolutionarily advantageous for a wide variety of animals to pick up emotional cues from other animals’ vocalizations—for example, a long cry that indicates more than one species is a predator nearby.