According to new research, people can understand vocalizations associated with negative situations experienced by these animals.
A study by the University of Amsterdam, in the Netherlands, the University of York, in the United Kingdom, and the Max Planck Institute for Evolutionary Anthropology, in Germany, found evidence of the human ability to deduce meaning from chimpanzee vocalizations. The research was published on June 17 in the scientific journal Proceedings of Royal Society B.
Previous studies have pointed out that we humans are able to interpret what animals mean from the sounds they make – such as the cat’s purr, the dog’s bark, and even the lion’s roar. However, research was still lacking on how far this ability can go.
Therefore, the international team of scientists decided to investigate how people interpret the vocalizations of a species very close to ours: the chimpanzee. They carried out two experiments involving more than 3,400 volunteers, who heard the sounds of chimpanzees and then tried to deduce their context.
In the first test, the researchers asked participants to select, from a list of 10 behavior categories, those that were most associated with a sound emitted by the primates. People were unable to accomplish the task, so the researchers took another approach: they asked the volunteers to answer only “yes” or “no” when a sound was compatible with a behavioral word displayed on a computer.
The behavioral characteristics of chimpanzees were related to different situations: separated from the mother, attacked by an aggressor, being threatened, being denied food they like or dislike, discovering a large amount of food, getting scared, and copulating.
The researchers found that the volunteers were good at connecting vocalizations with just a few animal behaviors. They were able to understand the sounds made by chimpanzees when discovering a good meal, for example, or when they were denied food that they really liked. People more often failed to associate sounds produced during copulation or when a young chimpanzee was separated from its mother.
Scientists realized that, in general, people were better at connecting negative vocalizations. They believe that this may be related to the identification of vocalizations between species that are linked to survival skills in the wild.