Face masks are one of the cheapest and most effective non-pharmaceutical interventions available against airborne diseases such as COVID-19. Unfortunately, they have been met with resistance by a substantial fraction of the populace, especially in the U.S. In this study, we uncover the latent moral values that underpin the response to the mask mandate, and paint them against the country's political backdrop. We monitor the discussion about masks on Twitter, which involves almost 600k users in a time span of 7 months. By using a combination of graph mining, natural language processing, topic modeling, content analysis, and time series analysis, we characterize the responses to the mask mandate of both those in favor and against them. We base our analysis on the theoretical frameworks of Moral Foundation Theory and Hofstede's cultural dimensions. Our results show that, while the anti-mask stance is associated with a conservative political leaning, the moral values expressed by its adherents diverge from the ones typically used by conservatives. In particular, the expected emphasis on the values of authority and purity is accompanied by an atypical dearth of in-group loyalty. We find that after the mandate, both pro- and anti-mask sides decrease their emphasis on care about others, and increase their attention on authority and fairness, further politicizing the issue. In addition, the mask mandate reverses the expression of Individualism-Collectivism between the two sides, with an increase of individualism in the anti-mask narrative, and a decrease in the pro-mask one. We argue that monitoring the dynamics of moral positioning is crucial for designing effective public health campaigns that are sensitive to the underlying values of the target audience.

翻译：口罩是应对COVID-19等空气传播疾病最廉价且最有效的非药物干预措施之一。然而，这一措施在美国等地区遭到了相当比例民众的抵制。本研究旨在揭示支撑民众对口罩强制令反应的潜在道德价值观，并将其置于国家政治背景下进行分析。我们追踪了Twitter上关于口罩的讨论，时间跨度7个月，涉及近60万用户。通过结合图挖掘、自然语言处理、主题建模、内容分析和时间序列分析等方法，我们分别刻画了支持与反对口罩强制令的群体反应。分析基于道德基础理论和霍夫斯泰德文化维度理论框架展开。研究结果显示，尽管反口罩立场与保守派政治倾向相关，但反口罩者所表达的道德价值观却与保守派常用的价值观存在差异。具体而言，对权威和纯洁价值观的预期强调伴随着非典型的群体内部忠诚缺失。我们发现，强制令实施后，支持与反对方均降低了对关怀他人的重视程度，同时增强了对权威和公平的关注，进一步加剧了该议题的政治化。此外，口罩强制令逆转了两个群体间的个人主义-集体主义表达模式：反口罩叙事中的个人主义倾向增强，而支持方的个人主义倾向减弱。我们认为，监测道德立场动态对于设计敏感于目标受众潜在价值观的有效公共卫生宣传至关重要。