Primate Research Institute, Kyoto University, Inuyama, Aichi 4848506, Japan.
Proc Natl Acad Sci U S A. 2012 Feb 28;109(9):3588-92. doi: 10.1073/pnas.1108517109. Epub 2012 Feb 6.
Humans extensively help others altruistically, which plays an important role in maintaining cooperative societies. Although some nonhuman animals are also capable of helping others altruistically, humans are considered unique in our voluntary helping and our variety of helping behaviors. Many still believe that this is because only humans can understand others' goals due to our unique "theory of mind" abilities, especially shared intentionality. However, we know little of the cognitive mechanisms underlying helping in nonhuman animals, especially if and how they understand others' goals. The present study provides the empirical evidence for flexible targeted helping depending on conspecifics' needs in chimpanzees. The subjects of this study selected an appropriate tool from a random set of seven objects to transfer to a conspecific partner confronted with differing tool-use situations, indicating that they understood what their partner needed. This targeted helping, (i.e., selecting the appropriate tool to transfer), was observed only when the helpers could visually assess their partner's situation. If visual access was obstructed, the chimpanzees still tried to help their partner upon request, but failed to select and donate the appropriate tool needed by their partner. These results suggest that the limitation in chimpanzees' voluntary helping is not necessarily due to failure in understanding others' goals. Chimpanzees can understand conspecifics' goals and demonstrate cognitively advanced targeted helping as long as they are able to visually evaluate their conspecifics' predicament. However, they will seldom help others without direct request for help.
人类广泛地无私帮助他人，这在维持合作社会方面起着重要作用。虽然一些非人类动物也能够无私地帮助他人，但人类被认为在自愿帮助和各种帮助行为方面是独一无二的。许多人仍然认为，这是因为只有人类能够理解他人的目标，因为我们具有独特的“心理理论”能力，尤其是共同意向性。然而，我们对非人类动物帮助行为的认知机制知之甚少，特别是它们是否以及如何理解他人的目标。本研究为黑猩猩根据同种个体的需求灵活地进行有针对性的帮助提供了经验证据。在这项研究中，实验对象从一组随机的七个物体中选择一个合适的工具，然后将其转移给遇到不同工具使用情况的同种伙伴，这表明它们理解自己伙伴的需求。这种有针对性的帮助（即选择合适的工具进行转移）仅在帮助者能够直观评估其伙伴的情况时才会出现。如果视觉通道被阻塞，黑猩猩仍然会在被请求时试图帮助它们的伙伴，但无法选择并捐赠其伙伴所需的合适工具。这些结果表明，黑猩猩自愿帮助的局限性不一定是因为它们无法理解他人的目标。只要黑猩猩能够直观地评估它们同种个体的困境，它们就能理解同种个体的目标，并表现出认知上先进的有针对性的帮助。然而，它们很少会在没有直接求助的情况下帮助他人。
