Bonobos and chimpanzees exhibit human-like framing effects

Humans exhibit framing effects when making choices, appraising decisions involving losses differently from those involving gains. To directly test for the evolutionary origin of this bias, we examined decision-making in humans' closest living relatives: bonobos (Pan paniscus) and chimpanzees (Pan troglodytes). We presented the largest sample of non-humans to date (n = 40) with a simple task requiring minimal experience. Apes made choices between a ‘framed’ option that provided preferred food, and an alternative option that provided a constant amount of intermediately preferred food. In the gain condition, apes experienced a positive ‘gain’ event in which the framed option was initially presented as one piece of food but sometimes was augmented to two. In the loss condition, apes experienced a negative ‘loss' event in which they initially saw two pieces but sometimes received only one. Both conditions provided equal pay-offs, but apes chose the framed option more often in the positive ‘g...人类在做出选择时会表现出框架效应（framing effect），即对涉及损失的决策与涉及收益的决策采取不同的评估方式。为直接检验该偏差的进化起源，我们对与人类亲缘关系最近的现存类群——倭黑猩猩（Pan paniscus）与黑猩猩（Pan troglodytes）——开展了决策行为测试。本研究向迄今为止规模最大的非人动物受试样本（n = 40）呈现了一项仅需极少实践经验即可完成的简易任务。猿类需在两类选项间进行选择：一类为“框架式”选项，可获得偏好性食物；另一类为替代选项，可获得固定数量的中等偏好性食物。在收益情境下，猿类会经历正向“收益”事件：框架式选项初始仅呈现1份食物，但有时会追加至2份。在损失情境下，猿类则会经历负向“损失”事件：初始可见2份食物，但有时仅能获得1份。两种情境的最终收益完全一致，但猿类在正向“收益”场景中选择框架式选项的频率更高（原文内容未完整展示）