Department of Evolutionary Anthropology, Center for Cognitive Neuroscience, Duke University, Durham, NC 27708, USA.
Biol Lett. 2011 Feb 23;7(1):15-8. doi: 10.1098/rsbl.2010.0927. Epub 2010 Nov 24.
Although recent research has investigated animal decision-making under risk, little is known about how animals choose under conditions of ambiguity when they lack information about the available alternatives. Many models of choice behaviour assume that ambiguity does not impact decision-makers, but studies of humans suggest that people tend to be more averse to choosing ambiguous options than risky options with known probabilities. To illuminate the evolutionary roots of human economic behaviour, we examined whether our closest living relatives, chimpanzees (Pan troglodytes) and bonobos (Pan paniscus), share this bias against ambiguity. Apes chose between a certain option that reliably provided an intermediately preferred food type, and a variable option that could vary in the probability that it provided a highly preferred food type. To examine the impact of ambiguity on ape decision-making, we interspersed trials in which chimpanzees and bonobos had no knowledge about the probabilities. Both species avoided the ambiguous option compared with their choices for a risky option, indicating that ambiguity aversion is shared by humans, bonobos and chimpanzees.
尽管最近的研究调查了动物在风险下的决策，但对于当动物缺乏有关可用选择的信息时，它们在模糊条件下如何选择的问题，知之甚少。许多选择行为模型假设模糊性不会影响决策者，但对人类的研究表明，人们往往更不愿意选择模糊的选择，而不是具有已知概率的风险选择。为了阐明人类经济行为的进化根源，我们研究了与人类最亲近的亲属，黑猩猩（Pan troglodytes）和倭黑猩猩（Pan paniscus），是否也存在这种对模糊性的偏见。猿类在一个确定的选择和一个可变的选择之间做出选择，前者可以可靠地提供一种中等偏好的食物类型，后者提供一种高度偏好的食物类型的概率可能会有所不同。为了研究模糊性对猿类决策的影响，我们在实验中穿插了一些实验，让黑猩猩和倭黑猩猩对概率一无所知。与选择风险选择相比，这两个物种都回避了模糊的选择，这表明模糊厌恶是人类、倭黑猩猩和黑猩猩所共有的。
