Yamamoto Shinya, Tanaka Masayuki
Primate Research Institute, Kyoto University, Aichi, Japan.
J Comp Psychol. 2009 Aug;123(3):242-9. doi: 10.1037/a0015838.
Reciprocity is considered to be an explanation for altruism toward nonkin. Although there have been many theoretical studies and reciprocity is arguably prevalent in humans, little experimental work has investigated the proximate mechanism of reciprocity in nonhuman animals. The authors tested whether pairs of chimpanzees (Pan troglodytes) would achieve reciprocal cooperation, that is, whether chimpanzees take turns playing donor and recipient roles in an other-rewarding token insertion task. In this task, when a chimpanzee inserts a token into a vending machine, a food reward is delivered to another chimpanzee in an adjacent booth. For 3 pairs of chimpanzees, token insertion persisted in an alternate condition, in which the participants necessarily had to insert tokens alternately, but not in a free condition, in which they freely took turns inserting tokens. In the free condition, one of the chimpanzees was observed to perform a possible solicitation toward the partner who had previously inserted fewer tokens. These findings suggest that there is some difficulty in the occurrence of reciprocal cooperation in chimpanzees. Chimpanzees, differently from humans, might play a donor's role only on the partner's request, but not spontaneously.
互惠被认为是对非亲属利他行为的一种解释。尽管已经有许多理论研究，并且互惠行为在人类中可以说是普遍存在的，但很少有实验工作研究非人类动物互惠行为的近因机制。作者测试了成对的黑猩猩（Pan troglodytes）是否会实现互惠合作，也就是说，黑猩猩在一个给予对方奖励的代币插入任务中是否会轮流扮演给予者和接受者的角色。在这个任务中，当一只黑猩猩将一个代币插入自动售货机时，一份食物奖励会被送到相邻笼子里的另一只黑猩猩那里。对于3对黑猩猩来说，代币插入在交替条件下持续进行，在这种条件下参与者必须交替插入代币，但在自由条件下则不然，在自由条件下它们自由轮流插入代币。在自由条件下，观察到其中一只黑猩猩对之前插入代币较少的伙伴进行了可能的请求行为。这些发现表明黑猩猩发生互惠合作存在一些困难。与人类不同，黑猩猩可能仅在伙伴的请求下扮演给予者的角色，而不是自发地这样做。
