Despite the enormous strides made in recent years in the field of animal cognition, in the popular imagination other animals are still regarded as creatures of limited rationality, driven mostly by instincts useful to their survival. This is of course not the case, and we are far less unique than we like to think. Great apes, for example, build and use a wide variety of tools (chimpanzees use between 15 and 25 different ones per community), even ants are capable of selecting the most suitable tools and learning to use new ones, while a recent study has shown that chickens possess remarkable logical abilities and are capable of arithmetic and empathy. The latest confirmation that we have for too long underestimated the rest of the animal kingdom comes from Brazil, where it has been discovered that bearded capuchins, a species of monkey, also have traditions.

The traditions of monkeys

Bearded capuchins (Cebus libidinosus) that inhabit the forests of Fazenda Boa Vista in Brazil pass down useful behaviours from generation to generation — such as using tools to crack open palm nuts — as genuine cultural traditions. This is the finding of a new study entitled "Synchronized practice helps bearded capuchin monkeys learn to extend attention while learning a tradition", which made the cover of the scientific journal Proceeding of the national academy of science (Pnas).

An Italian among the researchers

The study, conducted on a population of bearded capuchins by a group of researchers that includes the Italian scientist Elisabetta Visalberghi of the Institute of Cognitive Sciences and Technologies of the National Research Council in Rome (Istc-Cnr), found that these animals learn from a young age how to use the tools needed to open hard-shelled fruit, and that the technique is passed down from generation to generation.

How learning takes place

"When an experienced capuchin uses tools, the attention of inexperienced ones is captured, significantly increasing the frequency with which these individuals perform behaviours relevant to learning tool use, such as striking a nut against an anvil or a stone against the nut," explained Elisabetta Visalberghi. "Even after the experienced capuchin has cracked its nut, the inexperienced ones continue to carry out these activities for several minutes."

The wisdom of elders

Just as with human cultural traditions, perpetuated through mechanisms such as imitation and teaching, young monkeys too learn by observing older, more experienced individuals. "The attention and activities of inexperienced individuals are triggered by the tool use of those who know more, and these influences are long-lasting," said the Istc-Cnr researcher. "It follows that the repeated practice of the actions required to use a tool correctly significantly increases the likelihood that young, inexperienced individuals will hone their skills and achieve the desired result."

The importance of teaching

The ability to crack open hard-shelled fruit — critically important to these monkeys' diet — is therefore not innate but the result of a lengthy period of "study" and years of practice. It is only around the age of 3–4 that young capuchins begin to successfully crack open the occasional nut, yet some individuals still struggle even at seven years of age, demonstrating the importance of the social context, which promotes the acquisition of this skill through the example set by experienced individuals.

The transmission of tradition

"The transmission of traditional behaviours is therefore not an exclusively human prerogative, however much humanity may be the most technologically advanced species with the most marked cultural differences," concluded Elisabetta Visalberghi. "Through the methodology we have developed to understand how young capuchins learn to use tools, it may be possible to discover that in other animal species too, social influences are equally powerful."