Center for Adaptive Behavior and Cognition, Max Planck Institute for Human Development, Lentzeallee 94, 14195 Berlin, Germany.
Anim Cogn. 2010 Jul;13(4):663-70. doi: 10.1007/s10071-010-0309-x. Epub 2010 Feb 4.
Helping others at no cost to oneself is a simple way to demonstrate other-regarding preferences. Yet, primates exhibit mixed results for other-regarding preferences: chimpanzees and tamarins do not show these effects, whereas capuchin monkeys and marmosets preferentially give food to others. One factor of relevance to this no-cost food donation is the payoff to the donor. Though donors always receive the same payoffs regardless of their choice, previous work varies in whether they receive either a food reward or no food reward. Here, I tested cotton-top tamarins in a preferential giving task. Subjects could choose from two tools, one of which delivered food to a partner in an adjacent cage and the other of which delivered food to an empty cage. Thus, subjects could preferentially give or withhold food from a partner. I varied whether subjects received food payoffs, whether a partner was present or absent, and whether the partner was a non-cagemate or the subject's mate. Results showed that the subjects' overall motivation to pull either tool declined when they did not receive any food. Additionally, they did not preferentially donate or withhold food, regardless of their own payoff or their relationship with the partner. Thus, cotton-top tamarins do not take advantage of cost-free food giving, either when they might gain in the future (mates) or when they have no opportunity for future interactions (non-cagemates).
帮助他人而不考虑自身利益是体现他人偏好的一种简单方式。然而，灵长类动物在他人偏好方面表现出混合的结果：黑猩猩和绢毛猴没有表现出这些效应，而卷尾猴和狨猴则更倾向于将食物给予他人。与这种无成本食物捐赠相关的一个因素是捐赠者的收益。尽管捐赠者无论选择如何，总是获得相同的收益，但之前的研究在他们是否获得食物奖励或没有食物奖励方面存在差异。在这里，我在偏好给予任务中测试了棉顶狨猴。被试可以从两种工具中选择一种，其中一种将食物传递给隔壁笼子里的伙伴，另一种将食物传递给空笼子。因此，被试可以优先选择给予或 withholding 食物给伙伴。我改变了被试是否获得食物奖励、是否有伙伴在场、以及伙伴是否是非笼伙伴还是被试的伴侣。结果表明，当被试没有获得任何食物奖励时，他们拉动任何工具的整体动机都会下降。此外，无论他们自己的收益或与伙伴的关系如何，他们都不会优先捐赠或 withholding 食物。因此，棉顶狨猴既不会利用免费的食物给予，也不会在未来（伴侣）或未来没有互动机会（非笼伙伴）时利用这种机会。
