Chimpanzees in the Congolese rainforests exhibit advanced foraging techniques, such as using sticks to create tools for extracting termites from the ground. This behavior raises questions about how these apes developed such sophisticated methods.
A team led by Andrew Whiten from the University of St. Andrews has investigated the cultural transmission of these tool-using behaviors among chimpanzee populations in Central and East Africa. Their research suggests that these techniques, including complex tool use, have been passed down through generations and may reflect a form of cumulative culture. This concept has traditionally been thought to be unique to humans.
The study, published in the journal Science, argues that chimpanzees possess a "tiny degree of cumulative culture," which indicates that some cultural learning occurs among these animals. While many species display cultural behaviors, cumulative culture emerges when individuals build upon the techniques of others, leading to more sophisticated practices that could not be independently acquired.
Cassandra Gunasekaram, a doctoral candidate at the University of Zurich, examined genetic data from 35 chimpanzee populations and compared it with their tool use. She discovered that populations exhibiting more complex tool use are often genetically related, while those utilizing simpler tools or none at all showed less genetic connection. This suggests that social learning and the exchange of ideas across populations play a significant role in the development of advanced foraging techniques.
The researchers propose that sexually mature female chimps may act as cultural bearers, migrating between groups and facilitating the sharing of techniques. This intermingling of populations is thought to contribute to the modestly cumulative culture observed in chimpanzees, challenging the notion that only humans possess such cultural capabilities.
However, some experts, including Claudio Tennie from the University of Tübingen, question whether the evidence presented truly supports the idea of humanlike cumulative culture in chimpanzees. He argues that the complexity of the skills exhibited might still be achievable through independent invention rather than social learning.
Dr. Whiten contends that his experiments provide evidence that these behaviors are significantly influenced by cultural transmission. While the exact mechanisms through which chimpanzees acquire these techniques remain uncertain, the study highlights the lengths to which these apes will go in pursuit of food.