Intelligence and culture in chimpanzees
Tetsuro MATSUZAWA, Primate Research Institute of Kyoto University
I have been conducting studies of chimpanzee intelligence both in the laboratory and in
the wild. Since 1986, I have visited Africa each year, as part of my continuing research
focusing on a community of around 20 wild chimpanzees near the small village of Bossou,
Guinea. The chimpanzees at Bossou are known to use a pair of stones as hammer and anvil to
crack open the hard shells of oil-palm nuts thereby gaining access to kernels. It takes
3.5 to 5 years for young chimpanzees to acquire this skill. Chimpanzees at Bossou have
developed a unique culture of manufacturing and using various kinds of tools including
leaf-folding for drinking water, ant-dipping, pestle-pounding, algae-scooping, and
leaf-cushion, in addition to nut-cracking. The culture is transmitted from one generation
to the next, with young individuals observing the behavior of adults carefully and then
attempting to imitate them. In another long-term project, begun in 1977, a chimpanzee
named Ai has been raised in the laboratory and learned visual symbols and ways of
interacting with humans. So far, she has acquired about 100 visual symbols including
lexigrams, Japanese Kanji characters, letters of the alphabet, and Arabic numerals, as
well as human speech and gestures to some extent. There is a community of 11 chimpanzees
at PRI at present, including the now pregnant Ai. Recent studies have focused on
imitation, tool use, and symbol use among members of this captive community. They have
revealed processes involved in the emergence and social propagation of skills unique to
the group. Careful observation over extended periods seems to play an important role in
the acquisition of skills both in the laboratory and in the wild, comparable to a
master-apprentice relationship in humans. My studies have led me to recognise the
importance of laboratory simulation in connection with field observation in understanding
chimpanzee intelligence.
Myowa-Yamakoshi, G. and Matsuzawa, T. (1999) Factors influencing imitation of
manipulatory actions in chimpanzees (Pan troglodytes). Journal of Comparative Psychology,
113, 128-136.
Biro, D. and Matsuzawa, T. (1999) Numerical ordering in a chimpanzee (Pan troglodytes):
Planning, executing, and monitoring. Journal of Comparative Psychology, 113, 178-185.
Matsuzawa, T. (1999) Communication and tool use in chimpanzees: Cultural and social
context. In: Hauser, M and Konishi, M. (eds.), "Neural mechanisms of
communication", MIT Press.