Hunting, Tools, and Sociality: A new evolutionary scenario for chimpanzees
Max Planck Institute for Evolutionary Anthropology
Carnivorouschimpanzee indigenous in the Taï Forest, Ivory
Chimpanzees and humans possess in common three
behavioural properties that distinguish them from the rest of the primates and mammals:
They are the only species in which all know living populations use regularly many
different types of tools, hunt regularly at least a few mammal species for meat, and live
in large groups with a flexible fission-fusion social structure. If some models of human
evolution have considered one or two of these behavioural patterns, none has stressed the
importance of the simultaneous presence of the three of them within the chimpanzee-human
clade. I propose here an evolutionary scenario of the evolution in chimpanzees and humans
of these three abilities and explain how this was possible thank to the appearance of new
cognitive capacities in this clade.
For flexible tool use and hunting to evolve, the acquisition of a
more elaborate understanding of causality as well as some notions of a theory of mind is
required. These cognitive abilities progressively appeared in our common ancestors when
they started to hunt arboreal prey for meat within flexible fission-fusion social groups.
The flexibility required to live in a fission-fusion social structure was an important
precondition for the acquisition of an elaborate understanding of causality and for being
able to adopt the perspective of the prey within trees, both abilities essential to hunt
successfully. Once those cognitive abilities are acquired, it became possible to
anticipate the benefit of tool use in novel situations, which led to both a more flexible
tool repertoire and more complex tool uses.
Boesch, C. and Boesch-Achermann, H. 2000. The Chimpanzees of the Taï Forest:
Behavioural Ecology and Evolution. Oxford: Oxford University Press.