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Laterality in hand use across four tool-use behaviors among the wild chimpanzees of Bossou, Guinea, West Africa

Humle, Tatyana, Matsuzawa, Tetsuro (2009) Laterality in hand use across four tool-use behaviors among the wild chimpanzees of Bossou, Guinea, West Africa. American Journal of Primatology, 71 (1). pp. 40-48. ISSN 0275-2565. (doi:10.1002/ajp.20616) (Access to this publication is currently restricted. You may be able to access a copy if URLs are provided) (KAR id:38032)

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Population-level right handedness is a human universal, whose evolutionary origins are the source of considerable empirical and theoretical debate. Although our closest neighbor, the chimpanzee, shows some evidence for population-level handedness in captivity, there is little evidence from the wild. Tool-use measures of hand use in chimpanzees have yielded a great deal of variation in directionality and strength in hand preference, which still remains largely unexplored and unexplained. Data on five measures of hand use across four tool-use skills-ant-dipping, algae-scooping, pestle-pounding and nut-cracking - among the wild chimpanzees of Bossou, Guinea, West Africa, are presented here. This study aims to explore age- and sex-class effects, as well as the influence of task motor, cognitive and haptic demands, on the strength and directionality of hand preference within and across all five measures of hand use. Although there was no age- or sex-class effect on the directionality of hand preference, immature <10 years old tended to be less lateralized than adults, especially adult females. Nut-cracking, the most cognitively complex of the four behaviors and the only one requiring complementary coordination of both hands, yielded the greatest strength in hand use with all adults expressing exclusive use of one hand over the other, without overall significant directional preference. The least lateralized behavior was pestle-pounding, which required bimanual coordination, but also imposed constraints owing to fatigue. It emerged that only the most hazardous tool use, i.e. ant-dipping, and the sole haptic task, i.e. the extraction by hand of crushed oil-palm heart, were laterally biased and both to the right. Shared motor or grip patterns in tool-use skills failed to reveal any specialization in hand use at the individual level. Finally, Bossou chimpanzees demonstrated a tendency for a population-level right-hand use.

Item Type: Article
DOI/Identification number: 10.1002/ajp.20616
Uncontrolled keywords: Bossou, Chimpanzee, Hand use, Laterality, Tool use, adult, captivity, handedness, hominid, specialization, tool use, wild population, aging, alga, animal, article, cognition, feeding behavior, female, Guinea, hand, hemispheric dominance, male, motor activity, Pan troglodytes, perception, physiology, sexual development, tool use, wild animal, Aging, Algae, Animals, Animals, Wild, Cognition, Feeding Behavior, Female, Functional Laterality, Guinea, Hand, Male, Motor Activity, Pan troglodytes, Perception, Sex Characteristics, Tool Use Behavior, Africa, Bossou, Guinea, Sub-Saharan Africa, West Africa, algae, Elaeis, Pan
Subjects: G Geography. Anthropology. Recreation > GN Anthropology
Q Science
Q Science > QL Zoology
Divisions: Faculties > Social Sciences > School of Anthropology and Conservation
Faculties > Social Sciences > School of Anthropology and Conservation > Biological Anthropology
Depositing User: Tatyana Humle
Date Deposited: 04 Apr 2014 14:22 UTC
Last Modified: 22 Jan 2020 04:06 UTC
Resource URI: (The current URI for this page, for reference purposes)
Humle, Tatyana:
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