Recent evidence for different tool kits, proposed to be based upon culture-like transmission, have been observed across different
chimpanzee communities across Western Africa. In light of these findings, the reported failures by seven captive juvenile
chimpanzees tested with 27 tool use tasks (Povinelli
2000) seem enigmatic. Here we report successful performance by a group of nine captive, enculturated chimpanzees, and limited
success by a group of six semi-enculturated chimpanzees, on two of the Povinelli tasks, the Flimsy Tool task, and the Hybrid
Tool task. All chimpanzees were presented with a rake with a flimsy head and a second rake with a rigid head, either of which
could be used to attempt to retrieve a food reward that was out of reach. The rigid rake was constructed such that it had
the necessary functional features to permit successful retrieval, while the flimsy rake did not. Both chimpanzee groups in
the present experiment selected the functional rigid tool correctly to use during the Flimsy Tool task. All animals were then
presented with two “hybrid rakes” A and B, with one half of each rake head constructed from flimsy, non-functional fabric,
and the other half of the head was made of wood. Food rewards were placed in front of the rigid side of Rake A and the flimsy
side of Rake B. To be successful, the chimps needed to choose the rake that had the reward in front of the rigid side of the
rake head. The fully enculturated animals were successful in selecting the functional rake, while the semi-enculturated subjects
chose randomly between the two hybrid tools. Compared with findings from Povinelli, whose non-enculturated animals failed
both tasks, our results demonstrate that chimpanzees reared under conditions of semi-enculturation could learn to discriminate
correctly the necessary tool through trial-and-error during the Flimsy Tool task, but were unable to recognize the functional
relationship necessary for retrieving the reward with the “hybrid” rake. In contrast, the enculturated chimpanzees were correct
in their choices during both the Flimsy Tool and the Hybrid Tool tasks. These results provide the first empirical evidence
for the differential effects of enculturation on subsequent tool use capacities in captive chimpanzees.
Keywords Tool use - Enculturation - Social learning - Chimpanzees