Chimpanzees are not just among the most brilliant of the animals. They also share the same ancestor with humans and this may be the reason why these mammals share a number of characteristics and traits that are similar to those of the humans.
In a new study, Catherine Hobaiter, from the School of Psychology and Neuroscience at the University of St. Andrews in the U.K., and colleagues have found that just like humans, chimps also engage in social learning, a behavioral trait that influences chimpanzee culture allowing it to gradually change overtime and which researchers hope could provide insights on how human culture has evolved.
"Researchers have been fascinated for decades by the differences in behavior between chimpanzee communities; some use tools some don't, some use different tools for the same job. These behavioral variations have been described as 'cultural', which in human terms would mean they spread when one individual learns from another," Hobaiter said.
For the new study "Social Network Analysis Shows Direct Evidence for Social Transmission of Tool Use in Wild Chimpanzees," which was published in the journal PLOS Biology on Sept. 30, Hobaiter and colleagues revealed how Sonso chimpanzees adopted two variations of using "leaf sponge," which was not detected in the animals in over two decades of observation.
One method involves making the sponge using moss or moss with a mixture of leaves while the other involves reusing sponges that were left by other chimps behind. The monkeys use the sponges as a feeding tool dipping them into the pond and sucking water out of them.
Video footages of the monkeys in the wild that were taken by the researchers showed an alpha male chimpanzee making the sponge while being watched by a dominant female. Within six days, seven additional chimps started to make and use the sponges, six of whom observed how it was made before adopting it and one simply reused a discarded sponge.
"Our study adds new evidence supporting the hypothesis that some of the behavioral diversity seen in wild chimpanzees is the result of social transmission and can therefore be interpreted as cultural, especially when considered together with previous results from the wild and captivity," the researchers wrote.
The researchers said that studying this behavior in chimpanzees, man's closest relative, and in other animals could shed light on early hominin culture and the evolutionary process that has given birth to modern human cultures.