The Evolutionary Roots of Social Comparison

社会比较过程是人类行为的一个基本特征，其背后的心理机制和过程在过去的几十年里得到了深入的研究。然而，到目前为止，人们对社会比较的进化基础知之甚少。非人类的动物也会进行自我-他人比较吗？或者这些广泛的社会比较仅限于人类？对非人类灵长类动物的研究表明，动物可能对他人的行为很敏感，并会调整自己的反应。例如，黑猩猩和卷尾猴拒绝参加实验，如果伴侣动物在相同的任务中得到更好的回报。乌鸦和乌鸦也表现出这种“不公平的厌恶”。这些研究表明，社会比较可能存在一个进化基础，但到目前为止，潜在的机制从未被系统地探索过。为了填补这一重要的理解空白，本项目旨在阐明社会比较的进化根源。我们将采用比较的方法，将社会心理学的实验范式与动物行为研究方法相结合。具体地说，与人类社会比较过程的经典研究类似，我们将研究伴侣的表现如何影响受试者在猴子(长尾猕猴、短尾猴)和鸟类(腐肉乌鸦、乌鸦)中的表现行为。这些物种特别擅长社会任务，因此非常适合我们的比较研究工作。更具体地说，为了研究社会比较的具体特征在非人类动物中是否已经明显，我们将使用已经开发的经典范式来研究人类社会比较的潜在机制。我们将使用触摸屏上的平行表演来调查猴子和鸟类的社交比较是否分别受到受试者S和合作演员S之间的相对差异以及他们之间的个人关系(第一行)、受试者在其群体中的社会地位(第二行)以及将焦点转移到相似或不同特征的事先启动程序的影响(第三行)。为了验证比较方法，我们还将进行1号线和3号线的人类参与者实验。此外，2号线的试验与P7密切合作，反映了我们努力实现真正跨学科方法的雄心。

Social comparison processes are a fundamental characteristic of human behavior, and the underlying psychological mechanisms and processes have been intensively investigated in the last decades. Yet, until now, relatively little is known about the evolutionary foundations of social comparisons. Do non-human animals also engage in self-other comparisons or are these extensive social comparisons restricted to humans? Studies on non-human primates indicate that animals may be sensitive to the actions of others and adjust their responses. Chimpanzees and capuchin monkeys, for example, refuse to participate in experiments, if a partner animal is receiving better rewards for the same task. Crows and ravens also show this `inequity aversion¿. These studies suggest that there may be an evolutionary basis for social comparisons, but until now the underlying mechanisms have never been explored systematically. In an attempt to fill this important gap in understanding, the present project aims to elucidate the evolutionary roots of social comparisons. We will adopt a comparative approach and combine experimental paradigms from social psychology with animal behavior research methods. Specifically, in an analogy to classic research on social comparison processes in humans, we will examine how the performance of a partner influences subjects¿ performance behavior in monkeys (long-tailed macaques, Macaca fascicularis) and birds (carrion crows, Corvus corone). These species are particularly skilled at social tasks and thus ideally suited for our comparative research endeavor. More specifically, to examine whether specific features of social comparisons are already evident in non-human animals, we will use classic paradigms that have been developed to examine the underlying mechanisms of social comparisons in humans. Using parallel performances on touch-screen setups, we will investigate whether social comparisons in monkeys and birds are influenced by the relative difference between the subject¿s and the co-actor¿s performance as well as the personal relationship between them (Line 1), the social status of the subject within its group (Line 2) as well as prior priming procedures to shift the focus to similarity or dissimilarity features, respectively (Line 3). To validate the comparative approach we will conduct the experiments of Line 1 and 3 with human participants, too. Furthermore, experiments of Line 2 are in close collaboration to P7 reflecting our ambition to strive for a truly interdisciplinary approach.