ESM delay maintenance data from Waiting for a better possibility: delay of gratification in corvids and its relationship to other cognitive capacities

Self-control, the ability to resist temptation and wait for better but delayed possibilities, is an important cognitive skill that underpins decision-making and planning. The capacity to exert self-control has been linked to intelligence in humans, chimpanzees and most recently cuttlefish. Here, we presented 10 Eurasian jays, Garrulus glandarius, with a delayed maintenance task, which measured the ability to choose a preferred outcome as well as the ability to sustain the delay prior to that outcome. Jays were able to wait for better possibilities, but maximum wait times varied across the subjects. We also presented them with five cognitive tasks that assessed spatial memory, spatial relationships and learning capacity. These tasks are commonly used as measures of general intelligence within an ecological context. Individual performance was correlated across the cognitive tasks, which suggests that there was a general intelligence factor underlying their performance. Performance in these tasks was correlated significantly with the jays' capacity to wait for better possibilities. This study demonstrates that self-control and intelligence are correlated in jays. The fact that this correlation exists in diverse species suggests that self-control is a fundamental feature of cognition. Our results are discussed in the context of convergent evolution.This article is part of the theme issue ‘Thinking about possibilities: mechanisms, ontogeny, functions and phylogeny’.

自我控制（Self-control）指抵御诱惑、等待更佳但延迟的回报的能力，是支撑决策与规划的重要认知技能。已有研究证实，人类、黑猩猩以及近期研究中的乌贼均存在自我控制能力与智力水平相关联的现象。本研究中，我们为10只欧亚松鸦（Garrulus glandarius）设置了延迟维持任务，该任务可同时评估受试个体选择偏好回报的能力，以及在获得该回报前维持等待状态的能力。松鸦能够等待更佳回报，但个体间的最长等待时长存在差异。我们还为它们设置了五项认知任务，分别评估空间记忆、空间关系认知与学习能力。这类任务在生态学语境下通常被用作一般智力（general intelligence）的评估手段。各项认知任务中的个体表现呈现显著相关性，这表明松鸦的认知表现背后存在一个一般智力因子。上述认知任务中的表现与松鸦等待更佳回报的能力存在显著相关性。本研究证实，松鸦的自我控制能力与智力水平存在关联。这一关联在多个不同物种中均被发现，这表明自我控制是认知活动的一项核心特征。我们将结合趋同演化（convergent evolution）的视角对本研究结果展开讨论。本文属于专题栏目“可能性思考：机制、个体发育、功能与系统发育”的组成部分。