The branch of social science known as “legacy studies” has identified the stubborn persistence of political differences, such as levels of prejudice and trust, even between communities that are geographically proximate and otherwise largely similar. The theoretical focus of this literature has largely been on establishing the origin of political divergence. I add instead to theories explaining why such differences manage to persist across time, focusing explicitly on how neighbouring communities with political differences can, under certain circumstances, neither influence nor be influenced by each other. Using a series of simple evolutionary games, I demonstrate that differences can persist so long as intra-community interactions are sufficiently more likely than cross-community interactions. These conditions remain substantively easy to meet across a variety of basic game designs, providing further theoretical basis for the empirical findings of legacy studies.

中文翻译：

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邻近社区之间持续且自我延续的政治分歧

被称为“遗产研究”的社会科学分支已经发现了顽固的政治差异，例如偏见和信任程度，即使是在地理位置接近且其他方面基本相似的社区之间也是如此。这些文献的理论焦点主要集中在确定政治分歧的根源上。相反，我补充了一些理论来解释为什么这种差异能够随着时间的推移而持续存在，并明确关注具有政治差异的邻近社区如何在某些情况下既不会相互影响，也不会被彼此影响。通过使用一系列简单的进化游戏，我证明只要社区内互动比跨社区互动更有可能，差异就可以持续存在。这些条件在各种基本游戏设计中仍然很容易满足，为遗留研究的实证结果提供了进一步的理论基础。