"This study demonstrates apes do copy members of their own species and they develop different traditions by doing so," said Dr. Horner. "It makes it likely differences in tool use between wild chimpanzee communities in Africa indeed reflect a form of culture and establishes another link between human and chimpanzee societies."
The conformity bias finding was an unexpected, but equally important, result of this culture study, according to Dr. Horner. A few members of each group independently discovered the alternative method for freeing food from the Pan-pipes, but this knowledge did not endanger the groups' traditions because most of these chimpanzees reverted back to the norm set by their local expert. "Choosing the group norm over the alternative method shows a level of conformity we usually associate only with our own species," said Dr. Horner. "By using the group's technique rather than the alternative method, we see the conformity is based more on a social bond with other group members than the simple reward of freeing the food."
A characteristic traditionally thought to be solely human, the propensity to conform, may be part of an evolutionary progression. "These results suggest an ancient origin for the cultural conformism that is so evident in humans," said de Waal. "Further research may reveal these findings to be more widespread throughout the animal kingdom."