Although this behavior has been reported at Bali’s Uluwatu Temple for years, it has never been scientifically studied in the wild. Therefore, Fany Brotcorne, a primatologist from the University of Brussels in Belgium, and some of her colleagues set out to discover how and why this talent has spread through the monkey population. This behavior is only found in monkeys who live at this temple, which suggests it’s a learned behavior rather than an innate ability. Brotocorne wanted to discover whether it was indeed cultural, which would give us a better understanding of the monkey’s cognitive abilities, and even human evolution.
Robbing and Bartering
Brotcorne spent four months observing four different groups of monkeys that live near the temple. The two groups that spent more time around tourists had the highest rates of robbing and bartering, supporting the idea that they learn the behavior by watching each other. Groups with more young males, who are known for their risky behavior, also had higher rates than other groups.
Although this was a small study, Brotcorne still believes that her team has found the first preliminary evidence that the behavior is a cultural one that has been transmitted across generations by monkeys learning from one another.
In the years since these observations, she has found more evidence: the members of a new group that moved in around the temple have also learned that they can use stolen goods to get food.
Serge Wich, a primatologist from Liverpool’s John Moores University in the UK, declares that Brotcorne’s study provides us with “A novel and quite spectacular example of flexibility in primate behavior in response to environmental changes.” Furthermore, the fact that this behavior isn’t found in other places where it could occur “indicates that it can indeed be a new behavioral tradition in primates and one that teaches us that new traditions can involve robbing and bartering with different species,” he says.
Brotcorne states that her work will help researchers learn more about the psychology of primates: how information is transmitted among groups, how they plan for the future, and how much they understand their own actions.
Furthermore, it could also help us answer questions about the evolution of our own cognitive abilities. She states that “bartering and trading skills are not well known in animals. They are usually defined as exclusive to humans.” But seeing it in these macaques could help us learn how the early behavior might have come about in the evolution of the human lineage.
Bonus Video: A Cheeky Macaque in Action