Able-bodied wild chimpanzees imitate a motor procedure used by a disabled individual to overcome handicap
Abstract
Chimpanzee culture has generated intense recent interest, fueled by the technical complexity of chimpanzee tool-using traditions; yet it is seriously doubted whether chimpanzees are able to learn motor procedures by imitation under natural conditions. Here we take advantage of an unusual chimpanzee population as a 'natural experiment' to identify evidence for imitative learning of this kind in wild chimpanzees. The Sonso chimpanzee community has suffered from high levels of snare injury and now has several manually disabled members. Adult male Tinka, with near-total paralysis of both hands, compensates inability to scratch his back manually by employing a distinctive technique of holding a growing liana taut while making side-to-side body movements against it. We found that seven able-bodied young chimpanzees also used this 'liana-scratch' technique, although they had no need to. The distribution of the liana-scratch technique was statistically associated with individuals' range overlap with Tinka and the extent of time they spent in parties with him, confirming that the technique is acquired by social learning. The motivation for able-bodied chimpanzees copying his variant is unknown, but the fact that they do is evidence that the imitative learning of motor procedures from others is a natural trait of wild chimpanzees.
Citation
Hobaiter , C & Byrne , R W 2010 , ' Able-bodied wild chimpanzees imitate a motor procedure used by a disabled individual to overcome handicap ' , PLoS ONE , vol. 5 , no. 8 , e11959 . https://doi.org/10.1371/journal.pone.0011959
Publication
PLoS ONE
Status
Peer reviewed
ISSN
1932-6203Type
Journal article
Description
Fieldwork of CH was generously supported by grants from the Wenner-Gren Foundation (http://wennergren.org) and the Russell Trust. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Collections
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