Comparing human and nonhuman primate handedness: Challenges and a modest proposal for consensus

Hopkins, William D.

doi:10.1002/dev.21139

Cited by 47 publications

(58 citation statements)

References 104 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The determination of group-level hand preference is generally based on two factors: the strength of the individual hand preference (i.e., handedness index) and the number of individuals investigated [e.g., Papademetriou et al, 2005]. Because bonobos (and other non-human primates) rarely exclusively use one hand for particular tasks (i.e., they have a relatively low handedness index), larger sample sizes are considered necessary to reliably detect a group-level bias (defined as >65% of the individuals in the group) [Hopkins and Cantalupo, 2005;Hopkins et al, 2012;Hopkins 2013aHopkins , 2013b. In this study, the exclusive use of either the left-or right-hand (i.e., a high handedness index) by the 15 bonobo individuals suggests that use of the right-hand by 66% of the individuals may reliably estimate a group-level right-hand bias for this particular complex manipulative behaviour.…”

Section: Lateralitymentioning

confidence: 99%

Nut‐cracking behaviour in wild‐born, rehabilitated bonobos (Pan paniscus): a comprehensive study of hand‐preference, hand grips and efficiency

Neufuss

Humle

Cremaschi

et al. 2016

American J Primatol

View full text Add to dashboard Cite

There has been an enduring interest in primate tool-use and manipulative abilities, most often with the goal of providing insight into the evolution of human manual dexterity, right-hand preference, and what behaviours make humans unique. Chimpanzees (Pan troglodytes) are arguably the most well-studied tool-users among non-human primates, and are particularly wellknown for their complex nut-cracking behaviour, which has been documented in several West African populations. However, their sister-taxon, the bonobos (Pan paniscus), rarely engage in even simple tool-use and are not known to nut-crack in the wild. Only a few studies have reported tool-use in captive bonobos, including their ability to crack nuts, but details of this complex tool-use behaviour have not been documented before. Here, we fill this gap with the first comprehensive analysis of bonobo nut-cracking in a natural environment at the Lola ya Bonobo sanctuary, Democratic Republic of the Congo. Eighteen bonobos were studied as they cracked oil palm nuts using stone hammers. Individual bonobos showed exclusive laterality for using the hammerstone and there was a significant group-level right-hand bias. The study revealed 15 hand grips for holding differently sized and weighted hammerstones, 10 of which had not been previously described in the literature. Our findings also demonstrated that bonobos select the most effective hammerstones when nut-cracking. Bonobos are efficient nutcrackers and not that different from the renowned nut-cracking chimpanzees of Bossou, Guinea, which also crack oil palm nuts using stones.

show abstract

Section: Lateralitymentioning

confidence: 99%

Nut‐cracking behaviour in wild‐born, rehabilitated bonobos (Pan paniscus): a comprehensive study of hand‐preference, hand grips and efficiency

Neufuss

Humle

Cremaschi

et al. 2016

American J Primatol

View full text Add to dashboard Cite

show abstract

“…See also Figure S2. and is not consistently expressed across a number of different behaviors ( [22][23][24], but see [25] for one exception). Consistent one-hand preference at the population level across a wide range of behaviors (so-called ''true'' handedness [26]) is considered to be a characteristic of humans [8,27,28].…”

Section: Figure 2 Lateralization Of Forelimb Use In Marsupialsmentioning

confidence: 99%

Parallel Emergence of True Handedness in the Evolution of Marsupials and Placentals

et al. 2015

View full text Add to dashboard Cite

Recent studies have demonstrated a close resemblance between some handedness patterns in great apes and humans. Despite this, comparative systematic investigations of manual lateralization in non-primate mammals are very limited. Among mammals, robust population-level handedness is still considered to be a distinctive human trait. Nevertheless, the comprehensive understanding of handedness evolution in mammals cannot be achieved without considering the other large mammalian lineage, marsupials. This study was designed to investigate manual lateralization in non-primate mammals using the methodological approach applied in primate studies. Here we show that bipedal macropod marsupials display left-forelimb preference at the population level in a variety of behaviors in the wild. In eastern gray and red kangaroos, we found consistent manual lateralization across multiple behaviors. This result challenges the notion that in mammals the emergence of strong "true" handedness is a unique feature of primate evolution. The robust lateralization in bipedal marsupials stands in contrast to the relatively weak forelimb preferences in marsupial quadrupeds, emphasizing the role of postural characteristics in the evolution of manual lateralization as previously suggested for primates. Comparison of forelimb preferences in seven marsupial species leads to the conclusion that the interspecies differences in manual lateralization cannot be explained by phylogenetic relations, but rather are shaped by ecological adaptations. Species' postural characteristics, especially bipedality, are argued to be instrumental in the origin of handedness in mammals.

show abstract

“…not as pronounced as in humans [13][14][15]. Additionally, neuroimaging studies of chimpanzees have shown functional lateralization in Broca's area homologue related to communicative behaviour [16] and in the hand knob, the motor-hand region of the precentral gyrus, in relation to reach-and-grasping responses [17].…”

Section: Introductionmentioning

confidence: 97%

The heritability of chimpanzee and human brain asymmetry

et al. 2016

Self Cite

View full text Add to dashboard Cite

Human brains are markedly asymmetric in structure and lateralized in function, which suggests a relationship between these two properties. The brains of other closely related primates, such as chimpanzees, show similar patterns of asymmetry, but to a lesser degree, indicating an increase in anatomical and functional asymmetry during hominin evolution. We analysed the heritability of cerebral asymmetry in chimpanzees and humans using classic morphometrics, geometric morphometrics, and quantitative genetic techniques. In our analyses, we separated directional asymmetry and fluctuating asymmetry (FA), which is indicative of environmental influences during development. We show that directional patterns of asymmetry, those that are consistently present in most individuals in a population, do not have significant heritability when measured through simple linear metrics, but they have marginally significant heritability in humans when assessed through three-dimensional configurations of landmarks that reflect variation in the size, position, and orientation of different cortical regions with respect to each other. Furthermore, genetic correlations between left and right hemispheres are substantially lower in humans than in chimpanzees, which points to a relatively stronger environmental influence on left-right differences in humans. We also show that the level of FA has significant heritability in both species in some regions of the cerebral cortex. This suggests that brain responsiveness to environmental influences, which may reflect neural plasticity, has genetic bases in both species. These results have implications for the evolvability of brain asymmetry and plasticity among humans and our close relatives.

show abstract

Comparing human and nonhuman primate handedness: Challenges and a modest proposal for consensus

Cited by 47 publications

References 104 publications

Nut‐cracking behaviour in wild‐born, rehabilitated bonobos (Pan paniscus): a comprehensive study of hand‐preference, hand grips and efficiency

Nut‐cracking behaviour in wild‐born, rehabilitated bonobos (Pan paniscus): a comprehensive study of hand‐preference, hand grips and efficiency

Parallel Emergence of True Handedness in the Evolution of Marsupials and Placentals

The heritability of chimpanzee and human brain asymmetry

Contact Info

Product

Resources

About