Data from: Are capuchin monkeys (Sapajus spp.) sensitive to lost opportunities? The role of opportunity costs in intertemporal choice

Principles of economics predict that the costs associated with obtaining rewards can influence choice. When individuals face choices between a smaller, immediate option and a larger, later option, they often experience opportunity costs associated with waiting for delayed rewards because they must forego the opportunity to make other choices. We evaluated how reducing opportunity costs affects delay tolerance in capuchin monkeys. After choosing the larger option, in the High cost condition subjects had to wait for the delay to expire, whereas in the Low cost different condition they could perform a new choice during the delay. To assess the effect of intake rate on choices, the Low cost same condition had the same intake rate ratio as the High cost condition. We found that capuchins attended both to intake rates and to opportunity costs. They chose the larger option more often in the Low cost different and Low cost same conditions than in the High cost condition, and more often in the Low cost different condition than in the Low cost same condition. Understanding how non-human primates represent and use costs in making decisions not only helps to develop theoretical frameworks to explain their choices but also addresses similarities with and differences from human decision making. These outcomes provide insights into the origins of human economic behaviour.经济学基本原理指出，与获取奖励相关的成本会影响个体的决策选择。当个体在小额即时奖励与大额延迟奖励之间进行抉择时，往往会因等待延迟奖励而承担机会成本（opportunity cost）——因为他们不得不放弃做出其他选择的机会。本研究以卷尾猴（capuchin monkeys）为研究对象，探究了机会成本的降低如何影响其延迟耐受能力。在选择大额奖励选项后，高成本组（High cost condition）的被试需等待至延迟时长结束；而在不同低代价组（Low cost different condition）中，被试可在延迟期间进行新一轮选择。为评估摄入速率对决策的影响，相同低代价组（Low cost same condition）与高成本组具有完全一致的摄入速率比。研究结果显示，卷尾猴同时会考量摄入速率与机会成本。相较于高成本组，卷尾猴在不同低代价组与相同低代价组中选择大额奖励选项的频率更高；且相较于相同低代价组，其在不同低代价组中选择大额奖励的频率更高。探明非人灵长类动物如何表征并利用成本进行决策，不仅有助于构建解释其选择行为的理论框架，也能为揭示人类决策的异同提供参考。本研究结果可为人类经济行为的起源提供新的洞见。