Data from: Social network analysis shows direct evidence for social transmission of tool use in wild chimpanzees.

Claims of culture in animals have been stimulated by studies on a wide
range of taxa revealing group-specific behavior patterns that remain
stable through generations, consistent with different behavioral
innovations spreading within groups by social transmission in a manner
similar to human culture. In chimpanzees, 39 behaviors have been
identified as 'cultural', because alternative genetic and
environmental explanations for the observed regional variation appear less
plausible. This interpretation is supported by experimental data from
captive chimpanzee groups. However, there is no experimental evidence for
social learning in the wild, nor has there been direct observation of
social diffusion of spontaneously occurring behavioral innovations. Here,
we document the spread of two novel tool-use variants,
'moss-sponging' and 'leaf-sponge re-use', in the Sonso
chimpanzee community of Budongo Forest, Uganda. We use traditional
network-based diffusion analysis (NBDA) to test whether these novel
behaviors spread by social learning, as well as a newly developed dynamic
version of NBDA, capable of capturing temporal aspects of acquisition,
i.e. how each successive personal observations impact the subsequent
acquisition of behavior. Both models provide strong evidence that
diffusion patterns of moss-sponging, but not leaf-sponge re-use, are
significantly better explained by social than asocial learning, therefore
showing that wild chimpanzees socially learned moss-sponging from each
other. The most conservative estimate of social transmission accounts for
85% of observed events with an estimated 11-fold increase in learning rate
for each time a novice observed an informed individual performing
moss-sponging. We conclude that group-specific behavioral variants in
chimpanzees can be socially learned, suggesting this prerequisite for
culture originated in a common ancestor of great apes and humans, long
before the advent of modern humans.