Comparative assessment of handedness for a coordinated bimanual task in chimpanzees (Pan troglodytes), gorillas (Gorilla gorilla) and orangutans (Pongo pygmaeus).

Abstract

Hand preferences for a coordinated bimanual task were assessed in a sample of 31 captive gorillas (Gorilla gorilla) and 19 captive orangutans (Pongo pygmaeus) and were compared with chimpanzee (Pan troglodytes) hand preferences in subjects that were matched on the basis of age, sex, and rearing history. The task required that the apes remove food from the inside edges of a symmetrical polyvinyl chloride pipe presented to them in their home cages. The results indicate significant species differences with chimpanzees showing population-level right-handedness and orangutans showing population-level left-handedness. The gorillas showed a nonsignificant trend toward righthandedness. The results are discussed in terms of possible ecological or biomechanical factors that may influence hand preferences in different ape species.The evolution of handedness has been a topic of historical (Warren, 1980) and contemporary debate (Fagot & Vauclair, 1991;Hopkins, 1996Hopkins, ,1999MacNeilage, Studdert-Kennedy, & Lindblom, 1987;Marchant & McGrew, 1991;McGrew & Marchant, 1997). The central issues surrounding evolutionary theories of handedness have focused on whether population-level right-handedness is a uniquely human adaptation and whether the mechanisms selecting for handedness are associated with the emergence of complex cognitive processes such as language or tool use (see Bradshaw & Rogers, 1993, for a review). Since the seminal review article on nonhuman primate handedness by MacNeilage et al. (1987), there have been a plethora of studies on the distribution of limb and hand preference in a variety of animal species, notably nonhuman primates. Although there continues to be considerable debate over whether population-level handedness is expressed in nonhuman primates, evidence has emerged for several measures suggesting population-level handedness in limb preferences in a variety of vertebrates (for reviews, see Bradshaw & Rogers, 1993;Hook-Costigan & Rogers, 1997;Rogers & Andrews, 2002;Ward & Hopkins, 1993 One difficulty with the interpretation of findings on handedness between species has been the lack of common measures of hand use. The most commonly used measure of hand preference is simple reaching, and many primate species have been tested for handedness using this task (see Lehman, 1993). For simple reaching, some have reported increasing preferential use of the right hand for nonhuman primate species more closely related to humans than for species more distantly related (see Westergaard, Kuhn, & Suomi, 1998, for a review), whereas others have not reported such effects (see Hopkins & Morris, 1993;McGrew & Marchant, 1997). Direct comparative studies of simple reaching in great apes that have used the same measures and testing procedures have revealed mixed results with some authors reporting populationlevel right-handedness (Olson, Ellis, & Nadler, 1990) and others not (Heestand, 1986). However, simple reaching is not a particularly complex motor task and is not the most sensitive measure of hand preference ...

Handedness in captive gorillas (Gorilla gorilla)

“…For the less complex tasks, i.e. leading limb (hand or foot), scratching, gesturing and carry/object manipulation, the majority of individuals showed no significant preferences, which supports previous findings (Fagot and Vauclair 1988;Hopkins et al 2003). As predicted by previous research (Fagot and Vauclair 1988;Olson et al 1990), a greater proportion of individuals were significantly lateralised when a more complex behaviour was performed, i.e.…”

“…Fagot and Vauclair (1988) found significant population-level left-hand preferences for feeding tasks that were complex in terms of biomechanical and cognitive demands required. Significant preferences at an individual but not population level have been found for general feeding and for coordinated bimanual feeding tasks (Fagot and Vauclair 1988;Hopkins et al 2003). In contrast other studies have found a lack of population-level preference while feeding (Olson et al 1990;Annett and Annett 1991) and for manipulating food (Olson et al 1990).…”

“…Previous results from feeding studies, bimanual feeding and food manipulation in captive populations have produced varied results, showing population-level preferences for either left or right hand, individual-level preferences or a lack of preferences (Fagot and Vauclair 1988;Olson et al 1990;Annett and Annett 1991;Hopkins et al 2003). In studies of food processing in wild populations, individual but no population-level preferences have been found (Byrne and Byrne 1991;Parnell 2001).…”

Further evidence of an association between handedness and neuroanatomical asymmetries in the primary motor cortex of chimpanzees (Pan troglodytes)

“…However, recent studies have documented evidence of population-level behavioral asymmetries in a host of nonhuman vertebrate species (Rogers & Andrew, 2002). With specific reference to primates, there is increasing evidence of population-level handedness in prosimians (Ward, Milliken, & Stafford, 1993), Old and New World monkeys (Hook-Costigan & Rogers, 1997;Spinozzi, Castornina, & Truppa 1998;Vauclair Mequerditchian, & Hopkins, 2005;Westergaard, Kuhn, & Suomi, 1998) and great apes (Hopkins, Stoinski, Lukas, Ross, & Wesley, 2003;Hopkins, Wesley, Izard, Hook, & Schapiro, 2004). Moreover, evidence of population-level neuroanatomical asymmetries have been reported in great apes.…”

Exploring the relationship between cerebellar asymmetry and handedness in chimpanzees (Pan troglodytes) and capuchins (Cebus apella)

“…While there is increasing evidence that captive and wild chimpanzees are similar to humans in expressing a tendency towards population-level right-handedness (Hopkins, Stoinski, Lucas, Ross & Wesley, 2003;Hopkins, Wesley, Izard, Hook & Shapiro, 2004;Lonsdorf & Hopkins, 2005) albeit to a lesser degree, the data for capuchins are less clear, with some research groups reporting population-level preferences (e.g., Spinozzi, Castorina, & Truppa, 1998) and others not (e.g., Fragaszy, Fedigan, & Visalberghi, 2004;Westergaard & Suomi, 1996). Individual capuchins do, however, express strong and consistent hand preferences during tasks that require complex bimanual coordination (Fragaszy & Mitchell, 1990;Limongelli, Sonetti, & Visalberghi, 1994;Westergaard & Suomi, 1993a,1993b.…”