Understanding the potential promotion mechanism for the formation and maintenance of cooperation is a pivotal issue in the development of human society and the natural world. Evolutionary games provide a forceful theoretical tool to probe into the essence of cooperative behaviors. It is considered that diversity (heterogeneity) is a common attribute of individuals and their interaction environment. We explore the propagation of cooperation under the influence of diversity and identify the similarities and discrepancies in the impact of internal and external sources of heterogeneity. The results show that heterogeneity, regardless of its origin, can promote the diffusion of cooperative behaviors. However, our researches further demonstrate that diversity of individual internal attributes is more conducive to the formation of cooperative behaviors than environmental heterogeneity. Moreover, we discuss the impact of asymmetry on the results and verify the robustness of the conclusions in different mixed game models. Our explorations shed some light on the promotion mechanism of cooperation from the perspective of sources of heterogeneity and highlight the role of diversity in the spread of altruistic behaviors.

了解合作形成和维持的潜在促进机制是人类社会和自然界发展的关键问题。进化博弈为探究合作行为的本质提供了强有力的理论工具。人们认为多样性（异质性）是个体及其交互环境的共同属性。我们探讨了在多样性影响下的合作传播，并确定了内部和外部异质性来源影响的异同。结果表明，异质性，无论其来源如何，都可以促进合作行为的扩散。然而，我们的研究进一步表明，个体内部属性的多样性比环境异质性更有利于合作行为的形成。此外，我们讨论了不对称性对结果的影响，并验证了结论在不同混合博弈模型中的稳健性。我们的探索从异质性来源的角度揭示了合作的促进机制，并突出了多样性在利他行为传播中的作用。