1. We like to tell tidy stories about why social unrest happens, and those stories usually involve themes of grievance or social injustice—things like hardship, inequality, corruption, discrimination, and political repression. One or more of those forces probably plays a role in many bouts of unrest, especially the ones that emerge from or evolve into sustained action like we’re seeing right now in Hong Kong and Ferguson.
Still, a riot over the weekend at a pumpkin festival in semi-rural Keene, New Hampshire, reminds us that you don’t need those big issues or themes to get to social unrest. According to the L.A. Times, in Keene,
Young people chucked beer cans and cups at each other, jumped off roofs, tore down, kicked and smashed road signs, set a large fire and chanted profanity, celebrated on top of a flipped car, took selfies in front of lines of riot police, got the attention of a police helicopter, chanted “U-S-A!”, pushed barricades and threw a street sign at police, threw bottles at the police after the police threw tear gas, and left behind a huge mess.
Why? Who knows, but the main ingredients in this instance seem to have been youth, alcohol, numbers, and the pleasure of transgression:
The description of the scene in Keene reminded me of the riots that sometimes erupt in college towns and sports-mad cities after big games, some of which have proven extremely destructive. These riots differ qualitatively from the rallies, marches, sit-ins, and the like that social scientists generally study. For two things, they usually aren’t planned in advance, and the participants aren’t making political claims. Still, I think our understanding of those ostensibly more political forms of collective action suffers when we make our causal narratives too tidy and ignore the forces that also produce these other kinds of outbursts.
2. Contagion is one of those forces that seems to operate across many forms of unrest. We’re sure that’s true, but we still don’t understand very well how that process works. Observers often use dominoes as a metaphor for contagion, implying that a given unit must fall in order for the cascade to pass through it.
A new paper on arXiv proposes another mechanism that allows the impulse to “hop” some units—in other words, to pass through them without producing the same type of event or effect. Instead of dominoes, contagion might work more like a virus that some people can catch and transmit without ever becoming symptomatic themselves. The authors think this mechanism could help to explain the timing and sequencing of protests in the Arab Spring:
In models of protests and revolutions, populations can have two stable equilibria—the size of the protest is either large or negligibly small—because of strategic complementarities (protest becomes more attractive as more people protest). During the Arab Spring, each country had unique grievances and agendas, and we hypothesize that each country had a unique proximity to a tipping point beyond which people would protest. Once protests began in one country (Tunisia), inspiration to protest spread to other countries via traditional media (such as newspapers) and via social media (such as Twitter and Facebook). This cross-border communication spread strategies for successful uprisings, and it increased expectations for success. Consequently, the uprisings began within a short window of time, seemingly cascading among countries more quickly than earlier revolutions did.
In coarse-grained data on the number of Facebook friendships between countries, we find evidence of the “cascade hopping” phenomenon described above. In particular, Saudi Arabia and Egypt appear to play the role of an intermediate country Y that propagated influence to protest from protesting countries to non-protesting countries, thereby helping to trigger protest in the latter countries, without themselves protesting until much later. Attributes of these intermediate countries and of the countries that they may have influenced to protest suggest that protests first spread to countries close to their tipping points (high unemployment and economic inequality) and strongly coupled to other countries via social media (measured as high Internet penetration). By contrast, we find that traditional measures of susceptibility to protest, such as political freedoms and food price indices, could not predict the order in which protests began.
As with the structural and dynamic stuff discussed around this weekend’s riot in Keene, this hopping mechanism will never be the only force at work in any instance of social unrest. Even so, it’s a useful addition to the set of processes we ought to consider whenever we try to explain or predict where and when other instances might happen.