Table_1_Chimpanzees Predict the Hedonic Outcome of Novel Taste Combinations: The Evolutionary Origins of Affective Forecasting.docx

Affective forecasting–predicting the emotional outcome of never-before experienced situations–is pervasive in our lives. When facing novel situations, we can quickly integrate bits and pieces of prior experiences to envisage possible scenarios and their outcomes, and what these might feel like. Such affective glimpses of the future often steer the decisions we make. By enabling principled decision-making in novel situations, affective forecasting confers the important adaptive advantage of eluding the potentially costly consequences of tackling such situations by trial-and-error. Affective forecasting has been hypothesized as uniquely human, yet, in a recent study we found suggestive evidence of this ability in an orangutan. To test non-verbal subjects, we capitalized on culinary examples of affective forecasting and devised a behavioral test that required the subjects to make predictions about novel juice mixes produced from familiar ingredients. In the present study, we administered the same task to two chimpanzees and found that their performance was comparable to that of the previously tested orangutan and 10 humans, who served as a comparison group. To improve the comparability of human and animal performance, in the present study we also introduced a new approach to assessing if the subjects’ performance was indicative of affective forecasting, which relies exclusively on behavioral data. The results of the study open for the possibility that affective forecasting has evolved in the common ancestor of the great apes, providing Hominids with the adaptive advantage of e.g., quickly evaluating heterogeneous food patches using hedonic prediction.

情感预测（affective forecasting），即预判从未经历过的情境所催生的情绪结果，在人类生活中无处不在。当面临全新情境时，我们能够快速整合零散的过往经验，构想可能出现的场景及其结局，甚至能预判这些场景将带来的主观感受。这类对未来的“情感预览”往往会主导我们的决策。通过为全新情境下的决策提供规范化指导，情感预测能够规避试错法应对此类情境时可能产生的高昂代价，这一适应性优势至关重要。此前，情感预测曾被认为是人类独有的能力，但在近期的一项研究中，我们在红毛猩猩（orangutan）身上发现了该能力存在的暗示性证据。为了测试非语言受试者，我们依托烹饪场景中的情感预测实例设计了一项行为测试，要求受试者对由熟悉原料调配而成的全新果汁混合饮品进行预判。在本研究中，我们将相同任务施测于两只黑猩猩（chimpanzee），结果发现它们的表现与此前接受测试的红毛猩猩以及作为对照组的10名人类受试者不相上下。为了提升人类与动物受试表现的可比性，本研究还引入了一种全新的评估方法，该方法仅依靠行为数据即可判断受试者的表现是否体现了情感预测能力。本研究的结果显示，情感预测可能演化自类人猿的共同祖先，这为人科动物（Hominids）带来了诸如借助享乐性预测快速评估异质性食物斑块等适应性优势。