Study

Cultures in chimpanzees

Whiten, Andrew; Goodall, Jane; McGrew, William C.; Nishida, Toshisada; Reynolds, Vernon; Sugiyama, Yukimaru; Tutin, Caroline E. G.; Wrangham, Richard W.; Boesch, Christophe

Nature, 1999

Peer-reviewedcomparative studywild

What they did

Researchers from seven long-running chimpanzee field sites pooled their records and compared which behaviours were present at each. Behaviours were counted as cultural only where they were customary at one site, absent at another, and where no ecological or genetic explanation for the difference could be found.

Studied in: Pan troglodytes
Sample size: 7 long-term field study sites, pooled across decades of observation

What they found

Thirty-nine behaviours, many of them involving tools, varied between sites in ways that ecology did not explain. Some communities cracked nuts with stones and others living in similar forest did not; termite-fishing techniques differed by group.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

Chimpanzee communities have distinct behavioural traditions transmitted socially, meeting the definition of culture used for human societies.

How NatureHQ reads it

The importance of this paper for a tool-use page is the method rather than the headline. It set the standard for how a claim about animal culture has to be argued: not "they do different things", but "they do different things and here is why the obvious non-cultural explanations do not work". The absence of a behaviour at a site is doing as much work as its presence.

Limitations

Absence of a behaviour at a site may reflect observation effort rather than genuine absence.
Ecological explanations can only be excluded as far as the ecological data allow.
Pooling records collected by different teams to different protocols introduces inconsistency.