  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.
