U.S. political division has outpaced other democracies

"There are good reasons to think that when people in different political camps cease to respect each other, it's harder to make political compromises and create good public policy." (Credit: Getty Images)

Americans’ feelings toward members of the other political party have worsened over time faster than those of residents of European and other prominent democracies, according to a new study.

Political polarization among Americans has grown rapidly in the last 40 years—a phenomenon possibly due to increased racial division, the rise of partisan cable news, and changes in the composition of the Democratic and Republican parties, researchers say.

In the study, the researchers present evidence showing long-term trends in “affective polarization”—a phenomenon in which citizens feel more negatively toward other political parties than toward their own. They found that in the US, affective polarization has increased more dramatically since the late 1970s than in the eight other countries they examined—the UK, Canada, Australia, New Zealand, Germany, Switzerland, Norway, and Sweden.

“A lot of analysis on polarization is focused on the US, so we thought it could be interesting to put the US in context and see whether it is part of a global trend or whether it looks more exceptional,” says coauthor Jesse Shapiro, a professor of political economy at Brown University. “We found that the trend in the US is indeed exceptional.”

Worsening political polarization

Using data from four decades of public opinion surveys conducted in the nine countries, the researchers used a so-called “feeling thermometer” to rate attitudes on a scale from 0 to 100, where 0 reflected no negative feelings toward other parties. They found that in 1978, the average American rated the members of their own political party 27 points higher than members of the other major party. By 2016, Americans were rating their own party 45.9 points higher than the other party, on average. In other words, negative feelings toward members of the other party compared to one’s own party increased by an average of 4.8 points per decade.

The researchers found that polarization had also risen in Canada, New Zealand, and Switzerland in the last 40 years, but to a lesser extent. In the UK, Australia, Germany, Norway, and Sweden, polarization decreased.

Why has the US become so much more polarized? Shapiro says it may be partly because, since the 1970s, major political parties have become increasingly aligned with certain ideologies, races, and religious identities. For example, Republicans are now more likely to be religious, while Democrats are more likely to be secular.

“There’s evidence that within the US, the two major political parties have become more homogeneous in certain ways, including ideologically and socially,” Shapiro says. “So when you identify with a certain party and you’re looking across the aisle, the people you’re looking at are more different from you than they were a few decades ago.”

That “party sorting” seems to be less pronounced in some of the other countries included in the study, Shapiro says—but it has perhaps played a role in deepening divisions in Canada.

The role of media

Another explanation for the increase in polarization—one that also seems relatively unique to the US, according to Shapiro—is the rise of 24-hour partisan cable news. Shapiro notes that in the countries where political polarization has fallen in the last four decades, public broadcasting received more public funding than it did in the US

The trio argue that the data speak against the rise of the internet as a major cause of political polarization because all nine countries have seen a pronounced rise in internet use, but not all of them have seen a rise in polarization.

The conclusion is consistent with other studies they have conducted, including one in 2018 that cast doubt on the hypothesized role of the web in the 2016 US presidential election and another in 2017 that concluded greater internet use among Americans is not associated with faster growth in polarization.

Shapiro says that understanding the root causes of political polarization, both in the US and elsewhere in the world, could help politicians and citizens alike understand how the phenomenon may be driving their decisions and preferences—and it could ultimately reveal strategies for bridging divides.

“There are good reasons to think that when people in different political camps cease to respect each other, it’s harder to make political compromises and create good public policy,” Shapiro says. “There’s also some evidence that a person’s political identity can influence their behavior—what they buy, where they live, who they hire. If we can understand what’s driving partisan divides, we may be able to take steps to reduce them.”

Additional researchers from Stanford University contributed to the study, which appears online as a National Bureau of Economic Research working paper.

Source: Brown University