The extent of differentiation of social relationships within groups is a means to assess social complexity, with greater differentiation indicating greater social complexity. Socio-ecological factors are likely to influence social complexity, but no attempt has been made to explain the differentiation of social relationships using multiple socio-ecological factors. Here, we propose a conceptual framework based on four components underlying multiple socio-ecological factors that influence the differentiation of social relationships: the extent of within-group contest competition to access resources, the extent to which individuals differ in their ability to provide a variety of services, the need for group-level cooperation and the constraints on social interactions. We use the framework to make predictions about the degree of relationship differentiation that can be expected within a group according to the cumulative contribution of multiple socio-ecological factors to each of the four components. The framework has broad applicability, since the four components are likely to be relevant to a wide range of animal taxa and to additional socio-ecological factors not explicitly dealt with here. Hence, the framework can be used as the basis for the development of novel and testable hypotheses about intra- and interspecific differences in relationship differentiation and social complexity.

群体内部社会关系的分化程度是评估社会复杂性的一种手段，更大的分化表明社会复杂性也更高。社会生态因素可能会影响社会的复杂性，但尚未尝试使用多种社会生态因素来解释社会关系的差异。在此，我们提出一个概念框架，该框架基于影响社会关系差异的多个社会生态因素的四个组成部分：小组内部竞争对资源的竞争程度，个人提供多种商品的能力不同的程度服务，团体合作的需求以及社交互动的限制。我们使用该框架根据多个社会生态因素对这四个组成部分的累加贡献，对一个组内可以预期的关系分化程度进行预测。该框架具有广泛的适用性，因为这四个组成部分可能与广泛的动物类群和此处未明确涉及的其他社会生态因素有关。因此，该框架可以用作发展关于关系分化和社会复杂性的种内和种间差异的新颖且可检验的假设的基础。因为这四个组成部分可能与广泛的动物类群和此处未明确处理的其他社会生态因素有关。因此，该框架可以用作发展关于关系分化和社会复杂性的种内和种间差异的新颖且可检验的假设的基础。因为这四个组成部分可能与广泛的动物类群和此处未明确处理的其他社会生态因素有关。因此，该框架可以用作发展关于关系分化和社会复杂性的种内和种间差异的新颖且可检验的假设的基础。