Individuals differ in the way they judge ambiguous information: some individuals interpret ambiguous information in a more optimistic, and others in a more pessimistic way. Over the past two decades, such "optimistic" and "pessimistic" cognitive judgment biases (CJBs) have been utilized in animal welfare science as indicators of animals' emotional states. However, empirical studies on their ecological and evolutionary relevance are still lacking. We, therefore, aimed at transferring the concept of "optimism" and "pessimism" to behavioral ecology and investigated the role of genetic and environmental factors in modulating CJB in mice. In addition, we assessed the temporal stability of individual differences in CJB. We show that the chosen genotypes (C57BL/6J and B6D2F1N) and environments ("scarce" and "complex") did not have a statistically significant influence on the responses in the CJB test. By contrast, they influenced anxiety-like behavior with C57BL/6J mice and mice from the "complex" environment displaying less anxiety-like behavior than B6D2F1N mice and mice from the "scarce" environment. As the selected genotypes and environments did not explain the existing differences in CJB, future studies might investigate the impact of other genotypes and environmental conditions on CJB, and additionally, elucidate the role of other potential causes like endocrine profiles and epigenetic modifications. Furthermore, we show that individual differences in CJB were repeatable over a period of seven weeks, suggesting that CJB represents a temporally stable trait in laboratory mice. Therefore, we encourage the further study of CJB within an animal personality framework.

中文翻译：

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曾经乐观，永远乐观？研究小鼠的认知判断偏差。

个体对模糊信息的判断方式有所不同：有些人以更乐观的方式解释模糊信息，而另一些人则以更悲观的方式解释。在过去的二十年里，这种“乐观”和“悲观”的认知判断偏差（CJB）已被动物福利科学用作动物情绪状态的指标。然而，对其生态和进化相关性的实证研究仍然缺乏。因此，我们旨在将“乐观”和“悲观”的概念转移到行为生态学中，并研究遗传和环境因素在调节小鼠 CJB 中的作用。此外，我们还评估了 CJB 个体差异的时间稳定性。我们表明，所选基因型（C57BL/6J 和 B6D2F1N）和环境（“稀缺”和“复杂”）对 CJB 测试中的响应没有统计上的显着影响。相比之下，它们影响了 C57BL/6J 小鼠和来自“复杂”环境的小鼠的焦虑样行为，与 B6D2F1N 小鼠和来自“稀缺”环境的小鼠相比，它们表现出较少的焦虑样行为。由于所选基因型和环境不能解释 CJB 中存在的差异，未来的研究可能会调查其他基因型和环境条件对 CJB 的影响，此外，阐明其他潜在原因（如内分泌谱和表观遗传修饰）的作用。此外，我们发现 CJB 的个体差异在七周内是可重复的，这表明 CJB 代表了实验室小鼠的暂时稳定的特征。因此，我们鼓励在动物人格框架内进一步研究 CJB。