Baboons' hand preference resists to spatial factors for a communicative gesture but not for a simple manipulative action

Abstract

Olive baboons (Papio anubis) do acquire and use intentional requesting gestures in experimental contexts. Individual's hand preference for these gestures is consistent with that observed for typical communicative gestures, but not for manipulative actions. Here, we examine whether the strength of hand preference may also be a good marker of hemispheric specialization for communicative gestures, hence differing from the strength of hand preference for manipulative actions. We compared the consistency of individuals' hand preference with regard to the variation in space of either (i) a communicative partner or (ii) a food item to grasp using a controlled set-up. We report more consistent hand preference for communicative gestures than for grasping actions. Established hand preference in the midline was stronger for gesturing than for grasping and allowed to predict the consistency of hand preference across positions. We found no significant relation between the direction of hand preference and the task.

Patterns of hemispheric specialization for a communicative gesture in different primate species

“…When grasping, hand preferences of all the species were shown to depend on item's position, which is in accordance with several studies in monkeys, apes, and humans (Bourjade et al, 2013;Carlson & Harris, 1985;Chapelain et al, 2012;Cronholm, Grodsky, & Behar, 1963;Doyen, Dufour, Caroff, Cherfouh, & Carlier, 2008;Fagard, 1998;Lehman, 1980;Meunier et al, 2011), agreeing that reaching is strongly influenced by situational factors. In other words, humans (infants, children, and adults, e.g., Calvert & Bishop, 1998;Leconte & Fagard, 2006), as well as nonhuman primates, strongly prefer to use the hand that is closest to the item to be reached for in a simple reaching task.…”

“…We adapted this task in such a way that it could be used to investigate both human infants and nonhuman primates. Moreover, our adaptation of the QHP task included the design of two experiments to compare both hand preferences while subjects grasped an object and hand preferences while subjects displayed a communicative gesture (see also Bourjade, Meunier, Blois-Heulin, & Vauclair, 2013). One can remark that nonhuman primates do usually not point spontaneously for each other (but see in apes Inoue-Nakamura &Matsuzawa, 1997 andVeà &Sabater-Pi, 1998) and that pointing is a gesture more specific for nonhuman primate-human interactions (e.g., Call & Tomasello, 1994;Mitchell & Anderson, 1997).…”

“…Thus, our experimental paradigm allowed us to assess hand preferences in several species both in a communication task and a simple (manipulative) grasping task, while controlling spatial and postural factors, two factors considered to affect hand preferences (Bishop et al, 1996;Calvert & Bishop, 1998;Leconte & Fagard, 2004). Even though these positional factors may have a crucial influence on hand preferences, they have almost never been quantified in nonhuman primates (but see Bourjade et al, 2013;Chapelain et al, 2012;Meunier, Blois-Heulin, & Vauclair, 2011). The present report grouped results issued from several studies taking into consideration all of these critical methodological points.…”

Handedness in gestural and manipulative actions in male hunter‐gatherer Aka pygmies from Central African Republic

“…However, such results are also impressively consistent with the only similar previous study available on hunter‐gatherers (the Hadza, Tanzania, Cavanagh et al, ). In contrast, in non‐human primates and in western human infants (but not in adults, Cochet & Vauclair ), the strength of the hand preference is higher in gestures than in motor actions (e.g., primates: Bourjade et al, ; Hopkins & Leavens, ; Meguerditchian et al, ; infants: Cochet, Jover, & Vauclair, ). However, more surprisingly, we found that nonexplicitly informative gestures were more lateralized than explicitly informative ones.…”

“…We also recorded the position of the target of each behavior (i.e., the position of the objects collected or the localization of the target of the speech, Hopkins & Wesley, 2002; Bryden, Mayer, & Roy, ; Meunier et al, ; Bourjade, Bourjade, Meunier, Blois‐Heulin, & Vauclair, ). The different target positions were defined considering as 0° all the points constituting the bilateral mirror plan: target between ± 10° = “central” position, target between 10°‐180° = “right” and otherwise as “left”‐positioned.…”