Many people know that Bali is famous for its brazen monkeys who steal things from tourists and then exchange them for food. Scientists have found that animals have learned to determine the value of objects, and this is best done by older and more experienced representatives of the species living near the Uluwatu temple.
A study by scientists from the University of Lethbridge in Canada and Udayana University in Indonesia found that monkeys performed unprecedented economic decision-making processes when they stole things and kept them for ransom. This skill has already been preserved in their population, according to tests in captivity.
The researchers analyzed 333 monkeys at large from September 2015 to August 2016, followed by 16 more monkeys in 2019.
Age plays a role in this process, with older monkeys stealing items that people value more. All items that are most often stolen were divided into six groups: empty containers (phone cases and camera bags), accessories (hairpins and key rings), hats (hats and caps), shoes (slippers, sandals), glasses ( glasses and sunglasses), electronic devices and wallets (cell phones, cameras and wallets). The researchers then categorized these items into low-value, medium-value, and high-value groups based on how often people wanted to exchange them with monkeys.
Oddly enough, more often than not, people wanted to get their phones and wallets back. It was them that were stolen by the most adult monkeys. They learned that phones and wallets can be exchanged for more food than other things. Young individuals stole everything, but then learned that some items could not be exchanged for food.
Dr. Jean-Baptiste Leca, lead author of the study and associate professor of psychology at the University of Lethbridge, said that robbery and barter are expressions of the cultural intelligence of apes. This behavior has been observed in this population for 30 years.
This is the first example of such a culturally supported economy in free animals.