Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, 606-8501, Japan; Japan Society for the Promotion of Science, Chiyoda, Tokyo, 102-0083, Japan.
Department of Psychology, Graduate School of Letters, Kyoto University, Kyoto, 606-8501, Japan.
Behav Processes. 2021 Aug;189:104424. doi: 10.1016/j.beproc.2021.104424. Epub 2021 May 17.
Altruism is often considered as the ultimate form of prosociality and is defined as any act that benefits others without direct benefit to the actor. Many nonhuman species have been reported to express different forms of altruism, although their expression in experimental studies is highly dependent on the paradigm used. Tufted capuchin monkeys are one of the most studied species; however, the evidence for altruism in this species remains inconclusive. This study aimed to investigate whether two paradigms, adapted from those in which great apes have shown altruism, could be useful for revealing signs of altruistic capabilities in capuchins. Pairs of monkeys were tested in two experiments involving a similar mechanism but with different costs to acting altruistically. The first used a more costly operant sharing task in which an operator could unlock a door to allow a recipient to enter the room and share his food. The second consisted of a less costly helping task, in which the operator's food was secured but he could help the recipient to get other food that was in a locked container. The results suggest that capuchins, although apparently unwilling to share their food in a costly operant situation, might altruistically help selected recipients, in response to requesting by the latter. While our small sample size along with procedural limitations preclude firm conclusions, we discuss how further ameliorations of our tasks could further contribute to the study of altruistic capacities in primates.
利他主义通常被认为是亲社会行为的最高形式，它被定义为任何有益于他人而对行为者没有直接益处的行为。许多非人类物种都被报道表现出不同形式的利他主义，尽管它们在实验研究中的表现高度依赖于所使用的范式。卷尾猴是研究最多的物种之一；然而，关于这种物种的利他主义的证据仍然没有定论。本研究旨在探讨两个范式，这两个范式是从表现出利他主义的类人猿中改编而来的，是否可以用于揭示卷尾猴具有利他能力的迹象。在两项实验中，成对的猴子接受了测试，这两个实验涉及到类似的机制，但表现出利他主义的成本不同。第一个实验使用了一个成本更高的操作性分享任务，在这个任务中，一个操作者可以解锁一扇门，让一个接受者进入房间并分享他的食物。第二个实验由一个帮助任务组成，在这个任务中，操作者的食物是安全的，但他可以帮助接受者获得其他锁在容器里的食物。结果表明，虽然卷尾猴显然不愿意在高成本的操作性情况下分享他们的食物，但他们可能会在后者的请求下，表现出利他主义地帮助特定的接受者。虽然我们的小样本量以及程序限制排除了确定的结论，但我们讨论了如何进一步改进我们的任务，以进一步促进对灵长类动物利他能力的研究。
