Marmoset monkeys call each other by name, similar to humans. The primates are native to South America. Scientists from the Hebrew University of Jerusalem studied the interaction of 10 marmosets. The team found that the animals used unique calls with other monkeys. The co-author of the study said marmosets are the first non-human primates known to use names. Researchers studied marmosets in a variety of pairings. They then used A.I. to analyze more than 50,000 monkey calls. This allowed the scientists to see that the animals had names for each other.

The findings could shed light on how human language evolved. A researcher said: "People thought that human language was a singular phenomenon that popped out of nothing. We're starting to see evidence that this is not the case." He speculated on how marmosets developed a system of names. He said: "Marmosets live in small, monogamous family groups, and take care of their young together, much like humans do. These similarities suggest that they faced comparable evolutionary social challenges to our early pre-linguistic ancestors."