How precisely do bonobos (Pan paniscus) grasp small objects?

The general objective of this study was to compare the precise grasping behavior and inter-manual differences in performance between three Pan paniscus and five Homo sapiens in grasping small objects. We compared the temporal pattern of two submovements of consecutive grasping cycles, the (visuomotor) reaching and the (sensorimotor) grasping. Both species were similarly successful in this task, they showed a behavioral right-hand preference and preferred specific types of grips Bonobos required less time for reaching an object but a much longer time to grasp it than humans did. Thus, the species pursued different strategies. We assumed that this might be due to the different grip techniques. However, grip preferences did not serve a quicker intramanual performance but they pronounced differences between hands. Intermanual differences in timing were restricted to the reaching part and more strongly in bonobos than in humans. However the light hand need not necessarily perform quicker. As in the case of humans, we assume that attentional cues were focused more on preparing a proper grip with the light hand than on a quick performance. However strong intermanual differences in bonobos may indicate an overall stronger neuronal asymmetry in the motor organization of the finger musculature that prepare a proper grip than is true of humans.