Non-human primates evaluate choices based on quantitative information and subjective valuation of options. Non-human primates can learn to value tokens as placeholders for primary rewards (such as food). With those tokens established as a potential form of ‘currency’, it is then possible to examine how they respond to opportunities to earn and use tokens in ways such as accumulating tokens or exchanging tokens with each other or with human experimenters to gain primary rewards. Sometimes, individuals make efficient and beneficial choices to obtain tokens and then exchange them at the right moments to gain optimal reward. Sometimes, they even accumulate such rewards through extended delay of gratification, or through other exchange-based interactions. Thus, non-human primates are capable of associating value to arbitrary tokens that may function as currency-like stimuli, but there also are strong limitations on how non-human primates can integrate such tokens into choice situations or use such tokens to fully ‘symbolize’ economic decision-making. These limitations are important to acknowledge when considering the evolutionary emergence of currency use in our species.

This article is part of the theme issue ‘Existence and prevalence of economic behaviours among non-human primates’.

非人类灵长类动物根据定量信息和选项的主观估值来评估选择。非人类灵长类动物可以学习将代币作为主要奖励（例如食物）的占位符来评估。随着这些代币被确立为一种潜在的“货币”形式，就可以检查它们如何应对赚取和使用代币的机会，例如积累代币或彼此或与人类实验者交换代币以获得主要奖励。有时，个人会做出有效且有益的选择来获得代币，然后在适当的时候交换它们以获得最佳奖励。有时，他们甚至通过延迟满足或通过其他基于交换的互动来积累这种奖励。因此，非人类灵长类动物能够将价值与可能起到类似货币刺激作用的任意代币相关联，但对于非人类灵长类动物如何将此类代币整合到选择情况或使用此类代币来完全“象征”经济也存在很大限制做决定。在考虑我们物种中货币使用的进化出现时，承认这些限制很重要。

本文是主题“非人类灵长类动物经济行为的存在和流行”的一部分。