Chimpanzees are much more rational than previously thought. They, like humans, are capable of revising their beliefs when stronger evidence becomes available. This conclusion was reached by an international group of scientists who published their research in the journal Science.

Observations were made at the chimpanzee sanctuary on Ngamba Island in Uganda. The researchers, including specialists from the University of California (USA) and Utrecht University (Netherlands), set the animals a simple but revealing task.

The monkeys were offered two boxes, one of which contained food. First, they were given a weak hint to suggest the correct choice. And then they showed new, more convincing evidence that pointed to another box. It turned out that chimpanzees often changed their initial decision, following a more compelling argument.

“This kind of flexibility of thinking is often found in four-year-old children. It was interesting to show that chimpanzees can do this too,” said Emily Sanford, a researcher at the University of California.

To make sure that the monkeys’ behavior was not simply instinctive – such as reacting to the latest or brightest clue – the scientists conducted careful analysis and used computer simulations. It confirmed that the chimpanzees’ decisions corresponded precisely to a rational strategy.

This discovery challenges old ideas that the ability to form and change beliefs based on evidence is a unique human privilege.

“This research could help us take new insights into how we approach early development or how we model thinking in artificial intelligence systems,” Sanford said.

The next stage of the work will be to conduct similar experiments with children aged two to four years. Scientists want to compare how babies and chimpanzees revise their beliefs. In the long term, scientists hope to study other primates to create a comparative map of the mental abilities of different species. As Emily Sanford points out, the main takeaway from her work is simple: animals are capable of much more than we often think.