Hand preferences in human adults: Non-communicative actions versus communicative gestures

Evolutionary origins of human handedness: evaluating contrasting hypotheses

“…This study also showed that the strength of right-handedness for manipulative activities was much greater in adults than that reported in young children, whereas the difference with age was rather slight for pointing gestures. This comparison suggests that the emergence of hand preference in the course of human ontogeny may be driven by communicative gestures, and the later strengthening of right-hand preference for object manipulations may relate to an increasing need to use complex tools (Cochet and Vauclair 2012). In addition to changes in individual lateral bias with age, population-level right-handedness may also derive from communicative gesturing during development, although empirical data are still needed to further support this hypothesis.…”

“…A more reliable overview of hand preferences may be given by spontaneous behavior because it reflects an immediate motor component, unlike data collected with questionnaires (e.g., Cavill and Bryden 2003), but such studies are time-consuming. More recently, researchers have used experimental tasks in ecologically relevant contexts, namely contexts in which object use is necessary to reach a specific goal rather than those in which participants are directly asked to use a particular object (e.g., Cochet and Vauclair 2012). These different conditions lead to wide variations in sample sizes, which contribute to explaining the differences across studies in the reliability with which handedness is shown at the group level.…”

“…However, whereas the use of self-report questionnaires and complex experimental tasks is widespread in adults (e.g., Johansson et al 2006), ethological activities have seldom been coded (Marchant et al 1995). A recent study has assessed hand preferences in natural situations, through tasks eliciting familiar object manipulations and pointing gestures (Cochet and Vauclair 2012). Results revealed (1) significant but moderate correlations between hand-preference scores for pointing gestures and bimanual manipulation, and (2) no significant difference between communicative gestures and manipulative actions in the mean strength of hand preference.…”

“…First, we must compare tasks that are similar, which may be easier for noncommunicative activities than for communicative activities. Bimanual coordination activities can, for example, be observed with the same task in different ape species, including human infants and adults (e.g., Cochet and Vauclair 2012; Hopkins et al 2011; Meunier and Vauclair 2007). Between-species comparison may be more intricate for communicative activities because the gestures produced by human and nonhuman primates may not share the same properties, for example, in terms of communicative functions (e.g., Pika 2008), as illustrated by the case of triadic gestures, namely gestures that refer to an external entity for the benefit of another agent.…”

“…1Adapted from Vauclair and Cochet (2013). Mean handedness indices for communicative gestures and bimanual manipulation in chimpanzees (Meguerditchian et al 2010), human infants (Vauclair and Imbault 2009), and human adults (Cochet and Vauclair 2012). The handedness index is calculated using the formula (R − L)/(R + L), where R and L represent the total number of right- and left-hand responses.…”