In behavioral studies, observer effects can be substantial, even for habituated animals, but few studies account for potential observer-related phenomenon empirically. We used wild, habituated chacma baboons to explore two key assumptions of behavioral ecology (i) that observers become a “neutral” stimulus and (ii) that habituation is “equal” across group members. Using flight initiation distance (FID) methods within a personality paradigm, the behavioral responses of baboons suggested that observers were not perceived as neutral but instead viewed as a high-ranking social threat. Habituation was also not equal across group members, with repeatable individual differences more important than contextual factors (e.g., habitat) in determining the distance at which baboons visually oriented or displaced from observers. A strong correlation between individual visual tolerance and displacement tolerance (i.e., convergent validity) indicated a personality trait. We offer several suggestions for how to account for these factors and minimize potential bias in future studies.

在行为研究中，即使对于习惯的动物来说，观察者效应也可能很大，但很少有研究从经验上解释潜在的观察者相关现象。我们使用野生的、已习惯的查克玛狒狒来探索行为生态学的两个关键假设：（i）观察者成为“中性”刺激；（ii）群体成员之间的习惯是“平等的”。在人格范式中使用飞行起始距离（FID）方法，狒狒的行为反应表明，观察者并不被视为中立，而是被视为高级社会威胁。不同群体成员的习惯也不相同，在决定狒狒视觉定向或远离观察者的距离时，可重复的个体差异比背景因素（例如栖息地）更重要。个体视觉容忍度和位移容忍度之间的强相关性（即收敛效度）表明了人格特质。我们就如何考虑这些因素并最大限度地减少未来研究中的潜在偏差提供了一些建议。