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Research Article
Population-level right-handedness for a coordinated bimanual task in
naturalistic housed chimpanzees: replication and extension in 114
animals from Zambia and Spain
Article first published online: 15 OCT 2010
DOI: 10.1002/ajp.20895
© 2010 Wiley-Liss, Inc.
Issue
American Journal of Primatology
Special Issue: Special Section on the Effects of Bonds Between Human and Non-human Primates on Primatological Research and Practice
Volume 73, Issue 3, pages 281–290, March 2011
Abstract
Recently, many studies have been conducted on manual laterality in chimpanzees. Nevertheless, whether nonhuman primates exhibit population-level handedness remains a topic of considerable debate. One of the behaviors studied has been bimanual coordinated actions. Although recent studies have highlighted that captive chimpanzees show handedness at population level for these tasks, some authors have questioned the validity and consistency of these results. The first reason has been the humanization of the samples. The second one has been that the results refer to animals in American biomedical centers and the studies were conducted by the same team [WD Hopkins et al.]. This article aims to assess the laterality in bimanual coordination (tube task) activities in animals housed in an intermediate environment (Chimfunshi, Zambia). This has been conducted by replicating previous studies on similar samples (Mona Foundation, Spain), and then by extending the results to chimpanzees housed in intermediate settings. Individuals were evaluated through four experimental sessions (tests). Results indicated that 86% of the Chimfunshi sample was lateralized (48% RH, 38% LH). Furthermore, the sample showed population-level right-handedness in the mean handedness index, in Test 1, Test 2, and the first half of the study (Test 1+2). Rearing experience did not have an influence on hand preference. Taken together, the two sample (intermediate settings: Chimfunshi and Mona) results indicate a clear right-handedness. In conclusion, this replication and extension shows that (1) the Mona and Chimfunshi chimpanzees are right-handed in certain conditions, (2) the results are consistent with those obtained by Hopkins in captive settings, (3) the humanization of the samples does not affect manual laterality, (4) females are right-handed at population-level, but not males, and (5) these results reinforce the fact that the complexity of the task plays a dominant role in the expression of hand laterality among chimpanzees. Am. J. Primatol. 73:281–290, 2011. © 2010 Wiley-Liss, Inc.
Author Information
Email: Miquel Llorente (mllorente@fundacionmona.org)
*Correspondence: Miquel Llorente, Unitat de Recerca i Laboratori d'Etologia, Centre de Recuperació de Primats, Fundació Mona. Carretera de Cassà 1 km, 17457, Riudellots de la Selva, Girona, Spain
Publication History
- Issue published online: 27 JAN 2011
- Article first published online: 15 OCT 2010
- Manuscript Accepted: 22 SEP 2010
- Manuscript Revised: 15 SEP 2010
- Manuscript Received: 16 APR 2010
Funded by
- Fundación Atapuerca, Generalitat de Catalunya (Ajut de mobilitat d'estudiants de Master)
- Spanish Ministerio de Ciencia e Innovación. Grant Number: MICIIN-HAR2009-07223/HIST
- Universitat Rovira i Virgili. Grant Number: URV-2009AIRE-05
