Department of Research Methods in Early Child Development, Leipzig University.
Department of Psychology, University of Virginia.
J Comp Psychol. 2021 May;135(2):196-207. doi: 10.1037/com0000255. Epub 2020 Dec 14.
Chimpanzees help conspecifics achieve their goals in instrumental situations, but neither their immediate motivation nor the evolutionary basis of their motivation is clear. In the current study, we gave chimpanzees the opportunity to instrumentally help a conspecific to obtain food. Following recent studies with human children, we measured their pupil diameter at various points in the process. Like young children, chimpanzees' pupil diameter decreased soon after they had helped. However, unlike children, chimpanzees' pupils remained more dilated upon watching a third party provide the needed help instead of them. Our interpretation is that chimpanzees are motivated to help others, and the evolutionary basis is direct or indirect reciprocity, as providing help oneself sets the conditions for a payback. This is in contrast to young children whose goal is to see others being helped-by whomever-presumably because their helping is not based on reciprocity. (PsycInfo Database Record (c) 2021 APA, all rights reserved).
黑猩猩在工具情境中帮助同种个体实现目标，但它们的直接动机及其动机的进化基础尚不清楚。在目前的研究中，我们让黑猩猩有机会通过工具帮助同种个体获得食物。我们借鉴了最近对人类儿童的研究，在整个过程的不同时间点测量了他们的瞳孔直径。与年幼的孩子一样，黑猩猩在帮助他人后不久，其瞳孔直径就会缩小。然而，与儿童不同的是，当黑猩猩看到第三方提供所需的帮助而不是自己提供帮助时，他们的瞳孔仍然保持更大的扩张。我们的解释是，黑猩猩有帮助他人的动机，其进化基础是直接或间接的互惠，因为自己提供帮助为回报创造了条件。这与年幼的孩子形成了对比，他们的目标是看到他人得到帮助——无论帮助者是谁——可能是因为他们的帮助不是基于互惠。
