Some scientists define culture as a product of language and thus unique to humans. Whiten's team focused on seven groups of common chimps observed in Africa for periods ranging from 8 to 38 years. Careful review of studies yielded 39 such behaviors that were potentially available to all the communities. Chimps' cultural traditions included cracking nuts by using pieces of wood as hammer and anvil, sucking ants off sticks, clasping a comrade's arms overhead, and slapping tree branches to get attention. Whether such acts spread via imitation or other learning is unclear, Whiten says.
Scientists also know little about how chimps invent traditions.
Nevertheless, the study underscores a growing willingness to grant chimps at least rudimentary cultural capacities. Moreover, field-workers continue to uncover chimp cultural practices, adding to those that Whiten's group tallied. In a noncultural example of mental sophistication, de Waal and Emory coworker Lisa A. Parr report that chimps recognize facial similarities between unfamiliar chimp mothers and their sons, but not between chimp mothers and their daughters. Chimps' cultural affinity with humans has a particular poignancy, Whiten says. Chimpanzees are dying out, partly due to a thriving bush-meat trade in Africa.