Behaviour and Evolution Research Group and Scottish Primate Research Group, Psychology, School of Natural Sciences, University of Stirling, Stirling FK9 4LA, UK.
Anim Cogn. 2013 Jul;16(4):677-84. doi: 10.1007/s10071-013-0603-5. Epub 2013 Jan 31.
In most experimental work on animal cognition, researchers attempt to control for multiple interacting variables by training subjects prior to testing, allowing subjects to participate voluntarily, and providing subjects with food rewards. However, do such methods encourage selection bias from subjects' personalities? In this study, we trained eighteen zoo-housed capuchin monkeys (Sapajus apella) for two experiments, under conditions of positive reinforcement (i.e. food rewards) and free-choice participation. Using a combination of behavioral and rater-based methods, we identified and validated five personality dimensions in these capuchins (Assertiveness, Openness, Neuroticism, Sociability, and Attentiveness). Scores on Openness were positively related to individual differences in monkey task participation, reflecting previous work showing that such individuals are often more active, curious, and willing to engage in testing. We also found a negative relationship between scores on Assertiveness and performance on tasks, which may reflect the trade-offs between speed and accuracy in these animals' decision-making. Highly Assertive individuals (the most sociable within monkey groups) may also prioritize social interactions over engaging in research. Lastly, monkeys that consistently participated and performed well on both tasks showed significantly higher Openness and lower Assertiveness compared to others, mirroring relationships found between personality, participation, and performance among all participants. Participation and performance during training was clearly biased toward individuals with particular personalities (i.e. high Openness, low Assertiveness). Results are discussed in light of the need for careful interpretation of comparative data on animal cognition and the need for researchers to take personality selection bias more seriously.
在大多数动物认知的实验工作中，研究人员试图通过在测试前对被试进行训练、允许被试自愿参与以及提供食物奖励来控制多个相互作用的变量。然而，这些方法是否会鼓励被试个性的选择偏差？在这项研究中，我们对十八只圈养的卷尾猴（Sapajus apella）进行了两项实验，实验条件为正强化（即食物奖励）和自由选择参与。通过结合行为和评价者的方法，我们在这些卷尾猴中确定并验证了五个个性维度（果断性、开放性、神经质、社交性和注意力）。开放性得分与猴子任务参与的个体差异呈正相关，反映了先前的工作表明，这类个体通常更活跃、好奇，愿意参与测试。我们还发现果断性得分与任务表现之间存在负相关，这可能反映了这些动物在决策过程中速度和准确性之间的权衡。高果断性的个体（猴子群体中最善于社交的个体）可能也会将社交互动置于参与研究之上。最后，在两项任务中始终积极参与且表现良好的猴子的开放性得分明显较高，果断性得分明显较低，这与所有参与者中个性、参与度和表现之间的关系相吻合。训练期间的参与和表现明显偏向于具有特定个性的个体（即开放性高、果断性低）。研究结果在讨论中考虑了需要谨慎解释动物认知的比较数据，以及研究人员需要更加认真地对待个性选择偏差的问题。
