Societies are complex systems, which tend to polarize into subgroups of individuals with dramatically opposite perspectives. This phenomenon is reflected—and often amplified—in online social networks, where, however, humans are no longer the only players and coexist alongside with social bots—that is, software-controlled accounts. Analyzing large-scale social data collected during the Catalan referendum for independence on October 1, 2017, consisting of nearly 4 millions Twitter posts generated by almost 1 million users, we identify the two polarized groups of Independentists and Constitutionalists and quantify the structural and emotional roles played by social bots. We show that bots act from peripheral areas of the social system to target influential humans of both groups, bombarding Independentists with violent contents, increasing their exposure to negative and inflammatory narratives, and exacerbating social conflict online. Our findings stress the importance of developing countermeasures to unmask these forms of automated social manipulation.

社会是复杂的系统，往往会分化为具有截然相反观点的个人亚组。这种现象在在线社交网络中得到反映，并且经常被放大。在这种情况下，人类不再是唯一的参与者，而是与社交机器人（软件控制帐户）并存的。分析2017年10月1日加泰罗尼亚独立公投期间收集的大规模社会数据，其中包括将近100万用户产生的近400万Twitter帖子，我们确定了独立主义者和立宪主义者两个两极分化的群体，并对结构和情感角色进行了量化由社交机器人玩。我们证明了漫游器从社会系统的外围区域采取行动，以这两个群体的有影响力的人为目标，用暴力内容轰炸独立主义者，增加他们对负面和煽动性叙事的了解，并加剧在线社会冲突。我们的发现强调了开发对策以揭露这些形式的自动社交操纵形式的重要性。