The Evolutionary Roots of Social Comparison
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).