Evolution of prosocial behavior: a meta-analysis and new experiments

亲社会行为也许是将人类社会团结在一起的最重要的粘合剂，但在许多动物社会中也发现了各种形式的相互作用，其中一个个体为一个或多个同种提供了利益。尽管对哺乳动物和鸟类的亲社会行为进行了大量的实验研究，但是对于其进化原因还没有一致的解释。在本项目中，我们的目标是一方面使用荟萃分析系统地评估现有研究的结果，另一方面对具有不同社会制度的灵长类动物、食肉动物和啮齿动物进行额外的实验。通过元分析，我们研究了不同的实验方法和不同的实验选择选项可以解释亲社会行为的变化。我们自己的初步实验表明，区分无私和互利的亲社会行为可能很重要。前者似乎与合作和共同繁殖有关，而后者分布更广，可能为群体生活物种之间的合作行为提供基础。 通过这种方法，我们可以确定物种在社会组织、父母照顾类型、社会容忍度和认知能力方面的差异对无私和互利的亲社会行为分布的相对解释价值。为此，我们比较了相同的测量无私和互惠的亲社会行为的8种哺乳动物，不同的社会组织和照顾系统。通过这种系统和控制的比较方法，我们希望有助于更好地理解亲社会行为的原因和后果，由于术语不一致，研究方法和解释水平，直到现在还不可能。

Prosocial behavior is perhaps the most important glue that holds human societies together, but various forms of interactions in which an individual provides a benefit to one or more conspecifics are also found in many animal societies. Despite numerous experimental studies of prosocial behavior in mammals and birds, however, there are as yet no consensual explanations for its evolutionary causes. In this project, we aim to systematically evaluate the results of existing studies using a meta-analysis on the one hand, and to conduct additional experiments with primates, carnivores, and rodents with different social systems on the other hand. With the meta-analysis we investigate how much variation in prosocial behavior is explained by different experimental approaches and different experimental choice options. Our own preliminary experiments suggest that it might be important to distinguish between selfless and mutualistic prosocial behavior. The former appears to be associated with cooperative and communal breeding, whereas the latter is more widely distributed and may provide the basis for cooperative behavior among group-living species. With this approach, we can determine the relative explanatory value of species differences in social organization, type of parental care, social tolerance and cognitive abilities for the distribution of selfless and mutualistic prosocial behavior. To this end, we compare the identically measured selfless and mutualistic prosocial behavior of eight mammalian species that differ in their social organization and care system. With this systematic and controlled comparative approach, we hope to contribute to a better understanding of the causes and consequences of prosocial behavior, which has not been possible until now due to inconsistent terminology, study methods, and levels of explanation.