The list of distinctive human abilities keeps getting shorter. Once again, our close cousin the chimpanzee has chipped away a bit of our uniqueness. A new study demonstrates that these great apes possess the ability to mix elements of existing techniques to improve efficiency—a part of “cumulative culture.”
Investigators have long established that chimps and other animals develop new behaviors and copy them from each other. Researchers label this process “culture.” For example, chimps in different groups hunt in distinct ways, and succeeding generations learn these skills. But apparently humans are the only species to intentionally modify such techniques across generations, cumulatively creating a behavior or technology that no single human could have devised. (In fact, the incremental discovery of commonalities between humans and other primates is an example of cumulative culture.)
Research recently published in Scientific Reports asked whether chimps might have the ability to do the same—just at a more modest level. The answer was that chimps at least exhibit a type of creativity that’s a necessary part of cumulative culture—but researchers still haven’t observed the full process.
Scientists from the University of St. Andrews, in Scotland, invited chimps held captive at the National Center for Chimpanzee Care, in Texas, to participate in a series of three related tasks. Each task required that they use fingers to move a token out of a linear box with obstacles. In the first two challenges, extracting the token efficiently required different techniques. The third challenge prompted some of the chimps to eventually improve their efficiency by combining the techniques they had learned during the first two rounds.
The researchers argue that this ability to mix methods to increase efficiency represents the type of creativity that humans often employ in the improvement of processes across generations. This finding suggests that the last common ancestors of chimps and humans, perhaps six million years ago, possessed this ability as well.