Results_Data.xlsx from Chimpanzees prepare for alternative possible outcomes

When facing uncertainty, humans often build mental models of alternative outcomes. Considering diverging scenarios allows agents to respond adaptively to different actual worlds by developing contingency plans (covering one's bases). In a pre-registered experiment, we tested whether chimpanzees (<i>Pan troglodytes</i>) prepare for two mutually exclusive possibilities. Chimpanzees could access two pieces of food, but only if they successfully protected them from a human competitor. In one condition, chimpanzees could be certain about which piece of food the human experimenter would attempt to steal. In a second condition, either one of the food rewards was a potential target of the competitor. We found that chimpanzees were significantly more likely to protect both pieces of food in the second relative to the first condition, raising the possibility that chimpanzees represent and prepare effectively for different possible worlds.

当面临不确定性时，人类往往会构建对应不同备选结果的心理模型。通过考量不同的情境分支，行为主体可通过制定应急计划（即做好万全准备），适应性地应对不同的真实世界情境。在一项预注册实验中，我们检验了黑猩猩（Pan troglodytes）是否会为两种互斥的可能性做好准备。实验设置为：黑猩猩仅在成功阻止人类竞争者盗取食物的前提下，才能获取两份食物。其中一种实验条件下，黑猩猩能够明确知晓人类实验者会试图盗取哪一份食物；另一种实验条件下，人类竞争者的潜在目标为两份食物奖励中的任意一份。研究结果显示，相较于第一种条件，黑猩猩在第二种条件下显著更有可能同时保护两份食物，这提示黑猩猩能够表征不同的可能世界并据此开展有效的准备行为。