Consistent second-order motor planning by cotton-top tamarins (Saguinus oedipus): Evidence from a dowel task

One of the hallmarks of complex motor planning in humans involves grasping objects in preparation for future actions, termed second-order motor planning. This ability has an extended developmental trajectory in humans and is also shared with nonhuman primates. Here, we presented seven cotton-top tamarins with a dowel task that has prompted variable grasping behaviors for some primate species. Tamarins could use either an efficient grasp to bring food stuck onto the end of a dowel to their mouth (radial grasp) or an inefficient grasp that required repositioning (ulnar grasp). The tamarins were very consistent in their use of radial grasps. These data support the morphological constraint theory suggesting that species with limited dexterity (inability to perform precision grasps) may demonstrate more consistent second-order motor planning due to the increased cost of inefficient grasping postures. (PsycInfo Database Record (c) 2022 APA, all rights reserved).