Recent news headlines may leave a distinct impression that Americans are a divided nation, but in fact, when it comes to policy, most people still hold moderate views. A new study sheds light on why the two U.S. political parties may polarize without voters doing the same.
The findings, published in a paper by researchers from the Santa Fe Institute (SFI), Northwestern University and UCLA in this month’s SIAM Review – a journal published by Society for Industrial and Applied Mathematics (SIAM) – answers a long-standing question in political science as to why the two parties are so polarized.
According to Vicky Chuqiao Yang, a complexity postdoctoral fellow at SFI who co-authored the paper with researchers from Northwestern University and UCLA, “the polarization we see today is most likely the effect of political games the parties are playing to win votes.”
“It’s intuitive to think the parties are drifting because voters are holding more extreme views on policies and disagreeing with each other more,” Yang said. “It feels true because we see a lot of antipathy in the news and social media, but the true picture of polarization among the population is actually a lot more subtle than people think.”
Yang and her team – which includes Daniel Abrams, Associate Professor of Engineering Sciences and Applied Mathematics at Northwestern University, Adilson Motter, Charles E. and Emma H. Morrison Professor of Physics at Northwestern University, and Georgia Kernell, Assistant Professor in the Departments of Communication and Political Science at UCLA – show how this works in a new dynamic model detailed in the SIAM Review paper. Tested on 150 years’ worth of U.S. Congressional voting data and compiled using complex mathematical formulas, it describes why politicians become more polarized even as their constituents remain steadfast in the middle.
Central to the model is the concept that U.S. voters will vote for a political candidate who is “good enough,” rather than always voting for the best one. Called “satisficing,” the concept is a proven decision-making strategy that shows how people frequently settle for a satisfactory or adequate result rather than the optimal one.
Earlier models of electoral participation, including the popular Downsian model introduced by economist Anthony Downs in the 1950s, were based on a different decision-making assumption called maximizing, which asserts that everyone votes and that voters choose the candidate who is ideologically closest to their opinions. That assumption seems logical enough, said Yang, however, with this approach, political parties should drift toward the center of the political spectrum over time in order to capture the most votes — the exact opposite of what has recently played out in American politics.
Yang’s group takes a different tack in their model, which is the first to apply satisficing as a principle. If a person is satisfied with a candidate, then that candidate gets the vote. If a person is satisfied with both of two candidates, then the vote is cast at random. And if a person isn’t satisfied with either party, they don’t vote.
“Based on our results, we believe the satisficing concept is an important aspect of how people vote that helps us to understand what’s taking place in the real world,” said Abrams, underscoring the important role dynamic models play. “What we found is that if political parties tried to be more inclusive and were to move closer to the center, they would actually lose votes,” he said.
In fact, in test runs of their model, the researchers found that political parties can increase their likelihood of winning votes by sticking to extreme party lines and firmly establishing themselves farther from the middle of the spectrum ideologically.
“Boston Red Sox fans hate New York Yankee fans, but in reality their wider views about the game of baseball itself are moderate,” explained Yang, using the analogy of sports to illustrate the phenomenon. “There’s this tribal mentality that occurs that says you have to dislike the other camp even though both sets of fans love the game.”
The model also helps to explain why people want to identify with divided political groups, even though studies show that parties often don’t accurately represent the opinions of all members, added Kernell. “A crucial element of our model is turnout,” she said. “Parties need to turn out their base and moderating their position may be inversely related to invigorating a party’s core supporters.”
“It may seem like there are vast differences between the two parties today, but that has a lot more to do with party strategy than voters changing their attitudes toward public policies,” she said.