Widespread conspiracy theories, like those motivating anti-vaccination attitudes or climate change denial, propel collective action and bear society-wide consequences. Yet, empirical research has largely studied conspiracy theory adoption as an individual pursuit, rather than as a socially mediated process. What makes users join communities endorsing and spreading conspiracy theories? We leverage longitudinal data from 56 conspiracy communities on Reddit to compare individual and social factors determining which users join the communities. Using a quasi-experimental approach, we first identify 30K future conspiracists-(FC) and 30K matched non-conspiracists-(NC). We then provide empirical evidence of importance of social factors across six dimensions relative to the individual factors by analyzing 6 million Reddit comments and posts. Specifically in social factors, we find that dyadic interactions with members of the conspiracy communities and marginalization outside of the conspiracy communities, are the most important social precursors to conspiracy joining-even outperforming individual factor baselines. Our results offer quantitative backing to understand social processes and echo chamber effects in conspiratorial engagement, with important implications for democratic institutions and online communities.

中文翻译：

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是什么让人们加入阴谋社区？：社会因素在阴谋参与中的作用

广泛的阴谋论，如那些激发反疫苗接种态度或否认气候变化的阴谋论，推动集体行动并承担全社会的后果。然而，实证研究在很大程度上将阴谋论的采用作为个人追求，而不是作为社会中介过程进行研究。是什么让用户加入支持和传播阴谋论的社区？我们利用 Reddit 上 56 个阴谋社区的纵向数据来比较决定哪些用户加入社区的个人和社会因素。使用准实验方法，我们首先确定了 3 万名未来的阴谋家（FC）和 3 万名匹配的非阴谋家（NC）。然后，我们通过分析 600 万条 Reddit 评论和帖子，提供了社会因素在六个维度上相对于个人因素的重要性的实证证据。特别是在社会因素方面，我们发现与阴谋社区成员的二元互动和阴谋社区之外的边缘化是阴谋加入的最重要的社会先兆——甚至优于个人因素基线。我们的结果为理解阴谋参与中的社会过程和回声室效应提供了定量支持，对民主制度和在线社区具有重要意义。