AC3 talk: Radical flanks and public support for protest groups


Brent Simpson, University of South Carolina


Social movements are critical agents of social change but are rarely monolithic. Movements are often composed of distinct factions with unique agendas and tactics, and there is little consensus on how these factions complement – or impede – one another’s influence. A central debate concerns the effects of radical flanks. Do they increase support for more moderate factions – by making the latter seem more credible by contrast – or reduce support for moderate factions – by making an entire movement seem unreasonable? No prior work has presented casual evidence for radical flank effects. Here we present the results of two survey-experiments (total N = 2,772), including a study of the animal rights movement and a preregistered study of the climate change movement. Results consistently show that the presence of a radical flank within either movement leads to greater support for a moderate faction within the same movement. Further, it is the use of radical activist tactics, such as property destruction or violence – moreso than a radical agenda – that drives this effect. Results indicate this owes to a contrast effect: the use of radical tactics by one flank led a more moderate faction to appear less radical, even though all characteristics of the moderate faction were held constant. This perception led to greater identification with and, in turn, greater support for the more moderate faction. These dynamics suggest that collective action groups that employ unpopular tactics can increase popular support for other groups within the same movement, pointing to a hidden way in which movement factions can be complementary, despite their highly divergent approaches to social change.

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