TY - JOUR
T1 - Chimpanzees copy dominant and knowledgeable individuals
T2 - Implications for cultural diversity
AU - Kendal, Rachel
AU - Hopper, Lydia M.
AU - Whiten, Andrew
AU - Brosnan, Sarah F.
AU - Lambeth, Susan P.
AU - Schapiro, Steven J.
AU - Hoppitt, Will
N1 - Publisher Copyright:
© 2015 Elsevier Inc.
PY - 2015/1/1
Y1 - 2015/1/1
N2 - Evolutionary theory predicts that natural selection will fashion cognitive biases to guide when, and from whom, individuals acquire social information, but the precise nature of these biases, especially in ecologically valid group contexts, remains unknown. We exposed four captive groups of chimpanzees (Pan troglodytes) to a novel extractive foraging device and, by fitting statistical models, isolated four simultaneously operating transmission biases. These include biases to copy (i) higher-ranking and (ii) expert individuals, and to copy others when (iii) uncertain or (iv) of low rank. High-ranking individuals were relatively un-strategic in their use of acquired knowledge, which, combined with the bias for others to observe them, may explain reports that high innovation rates (in juveniles and subordinates) do not generate a correspondingly high frequency of traditions in chimpanzees. Given the typically low rank of immigrants in chimpanzees, a 'copying dominants' bias may contribute to the observed maintenance of distinct cultural repertoires in neighboring communities despite sharing similar ecology and knowledgeable migrants. Thus, a copying dominants strategy may, as often proposed for conformist transmission, and perhaps in concert with it, restrict the accumulation of traditions within chimpanzee communities whilst maintaining cultural diversity.
AB - Evolutionary theory predicts that natural selection will fashion cognitive biases to guide when, and from whom, individuals acquire social information, but the precise nature of these biases, especially in ecologically valid group contexts, remains unknown. We exposed four captive groups of chimpanzees (Pan troglodytes) to a novel extractive foraging device and, by fitting statistical models, isolated four simultaneously operating transmission biases. These include biases to copy (i) higher-ranking and (ii) expert individuals, and to copy others when (iii) uncertain or (iv) of low rank. High-ranking individuals were relatively un-strategic in their use of acquired knowledge, which, combined with the bias for others to observe them, may explain reports that high innovation rates (in juveniles and subordinates) do not generate a correspondingly high frequency of traditions in chimpanzees. Given the typically low rank of immigrants in chimpanzees, a 'copying dominants' bias may contribute to the observed maintenance of distinct cultural repertoires in neighboring communities despite sharing similar ecology and knowledgeable migrants. Thus, a copying dominants strategy may, as often proposed for conformist transmission, and perhaps in concert with it, restrict the accumulation of traditions within chimpanzee communities whilst maintaining cultural diversity.
KW - Chimpanzees
KW - Cultural diversity
KW - Culture
KW - Social learning strategies
KW - Transmission biases
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U2 - 10.1016/j.evolhumbehav.2014.09.002
DO - 10.1016/j.evolhumbehav.2014.09.002
M3 - Article
C2 - 27053916
AN - SCOPUS:84916878399
SN - 1090-5138
VL - 36
SP - 65
EP - 72
JO - Evolution and Human Behavior
JF - Evolution and Human Behavior
IS - 1
ER -