Hand preferences in coordinated bimanual tasks in non-human primates: A systematic review and meta-analysis

The evolutionary significance of hand preferences among non-human primates and humans has been studied for decades with the aim of determining the origins of the population-level tendency. In this study, a meta-analysis was conducted to statistically integrate data on hand preferences in non-human primates performing the tube task and other bimanual tasks to determine the presence and direction of manual laterality. Significant individual-level lateralization was obtained for these bimanual tasks. In nonhuman primates, 82% of the animals analysed showed right or left-hand preference performing the tube task, this figure being 90% for other bimanual tasks. In contrast with humans, no asymmetry was found at the population level. Additionally, population-level preferences were not found in either of the tasks, although a strong manual preference was found when performing the tube task and other bimanual tasks. Species was studied as a variable moderator throughout the meta-analysis. These results highlight the importance of standardized testing methodologies across species and institutions to obtain comparable data and fill the gaps in the taxonomy. •We systematically reviewed and meta-analysed data on hand preferences for the tube task and other bimanual tasks.•82% of animals (n = 2376) present individual preferences for the tube task and 90% (n = 917) for other bimanual tasks.•No population-level asymmetry was detected.•The strength of hand preferences was strong for both bimanual typologies of tasks.•We identified heterogeneity in results due to biological and psychological differences between non-human primate species.