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, <i>Garrulus glandarius</i>, 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，即抵御诱惑、等待更佳却延迟的回报的能力，是支撑决策与规划的重要认知技能。此前已有研究证实，自我控制能力与人类、黑猩猩以及近期被研究的乌贼的智力水平存在关联。本研究针对10只欧亚松鸦（*Garrulus glandarius*）开展了一项延迟维持任务实验，该任务可同时评估个体选择偏好结果的能力，以及在该结果兑现前维持延迟状态的能力。实验结果显示，松鸦能够等待更佳回报，但不同个体的最长等待时长存在显著差异。此外，我们还为其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常被用于衡量一般智力水平。研究发现，松鸦在各项认知任务中的表现存在相关性，这表明其认知表现背后存在一个一般智力因子。同时，这些认知任务的表现与松鸦等待更佳回报的能力显著相关。本研究证实，松鸦的自我控制能力与智力水平存在相关性。这一关联在多个不同物种中均被发现，提示自我控制是认知活动的一项核心特征。本研究结果将在趋同演化的研究框架下展开讨论。本文属于专题专栏"思考可能性：机制、个体发育、功能与系统发育"的一部分。