New research published in Science Advances suggests that economic decline and economic inequality are both tied to the emergence of polarization. The new study indicates that an unwillingness to interact with people outside one’s group is a contagious phenomenon that cannot be easily reversed.
“Polarization has long been a concern in US politics, and over the last decade or so it has become a highly visible problem all over the world. Obvious examples can be found in Brexit and the Presidency of Donald Trump, but also in the politics of India, Brazil and internally in the European Union,” said study author Alexander J. Stewart, a senior lecturer of Mathematical Biology at the University of St. Andrews.
“One important shift in recent years has been the emergence of increasingly polarized attitudes and discourse among the public at large, especially online. As someone who studies cultural evolution, this problem struck me as both socially important, but also an area where the perspective of cultural evolution could be valuable.”
“Cultural evolution is a framework for thinking about how beliefs, behaviors and ideas spread through a population via cultural transmission. That’s why I ended up working with Joanna Bryson and Nolan McCarty, who bring a wealth of expertise in Public Policy and Political Science, to try to model the way polarized attitudes develop from a cultural evolution perspective,” Stewart said.
The researchers created a mathematical model based on the study of cultural evolution and evolutionary game theory to examine the dynamics of in- and out-group interactions amid changing economic conditions. The model simulates the success of individuals who are repeatedly faced with the choice of interacting either with someone who is like them or unlike them, and assumes that in-group interactions tend to be less risky but offer fewer economic benefits compared to out-group interactions.
In addition, the model assumes that an individual’s economic success is tied to the performance of the economy and that individuals tend to mimic the behavior of other successful individuals.
Based on this model, Stewart and his colleagues found evidence that individuals tend to switch to more risk-averse strategies during both general economic decline and rising economic inequality, resulting in increasing polarization.
“We show that under a broad range of conditions, the trade-off between risk reduction and benefit maximization decreases out-group interactions, that is, increases polarization, when a population is faced with economic decline. We show that such group polarization can be contagious, and a subpopulation facing economic hardship in an otherwise strong economy can tip the whole population into a state of polarization,” the researchers explained in their study.
“Moreover, we show that a population that becomes polarized can remain trapped in that suboptimal state, even after a reversal of the conditions that generated the risk aversion and polarization in the first place.”
After analyzing data from the Cooperative Congressional Election Study (CCES) and American National Election Studies (ANES), the researchers also found that state-level economic inequality was positively associated with levels of political polarization in the United States.
“For me there are two big take aways from our study,” Stewart told PsyPost. “The first is that the health of our economy, especially the level of inequality, is strongly connected to the health of our public discourse. And the concern is that these things can reinforce each other — more polarization leads to worse governance which leads to more inequality which leads to more polarization and so on.”
“The second take away is that we have to think more carefully about how we can prevent polarization before it gets started. One important thing our model shows is that polarization is much harder to reverse than it is to prevent.”
Of course, it is unlikely that economic inequality is the only factor related to political polarization.
“Our work focusses on one particular mechanism that can lead to polarization. It’s a mechanism we believe is important and we show how it can work. But the real world is much more messy than any model, and so our work must be put in the wider context of inter-group conflict and cooperation, which of course is the subject of a great deal of fascinating research,” Stewart said.
“The major question that I think needs to be addressed is how the feedback loop between polarization, governance and inequality actually plays out, and how we can use our understanding of that to reverse polarization once it becomes entrenched.”
“As I mentioned above, this was an interdisciplinary collaboration between people with expertise in mathematical biology, political science and public policy. And now I’m talking to an audience interested in psychology. I think that kind of interdisciplinary approach is really important for tackling problems like this. It’s also really fun, so I figured I’d just point that out to everybody,” Stewart added.
The study, “Polarization under rising inequality and economic decline“, was published December 11, 2020.