Do protests and social movements matter? Do they really bring about change?

Answering this question is tricky. It’s not obvious, for example, how much the recent shift to the right in American politics reflects the efforts of the Tea Party movement and how much it reflects deeper developments such as increasing racial hostility and negative reactions to globalization. Sometimes a movement matters far less than the social, economic and political forces that give rise to the movement itself.

When social scientists do uncover evidence of a movement’s influence, we have tended to focus on three main pathways by which movements gain power: cultural, disruptive and organizational. On its own, each pathway turns out to be limited in its effect. But movements that have managed to combine all three, such as the civil rights movement in the 1950s and ’60s, have had lasting impact.

Movements are said to exercise “cultural” power when they shape public opinion, language and everyday behavior. Part of what social movements do is create new ideas that challenge the status quo. Some of these ideas never go anywhere, but others take hold even among people who never participate in the movement. People didn’t talk about “the 99 percent” as a way of personalizing the issue of economic inequality before the Occupy movement popularized the phrase. Afterward, the conversation changed: As the sociologists Sarah Gaby and Neal Caren showed in a 2016 article, discussion of inequality in mainstream newspapers increased threefold in the period after Occupy.

But cultural power is not everything. It is difficult to change people’s attitudes about controversial issues. Movements risk “preaching to the choir.” Those opposed to a movement’s goals or hostile to its constituency may also respond by deepening their opposition or hostility. You see this in the polarized reactions of fans to the national anthem protests in the National Football League. In addition, cultural power may change public opinion or discussion of an issue but not translate into other kinds of lasting institutional changes, as was the case with Occupy.