Axelrod - "Preventing extreme polarization of political attitudes"

December 15, 2021

After the 2020 general election and the January 6 insurrection, the country seems more politically polarized than ever. Ford School professor Robert Axelrod, the William D. Hamilton Distinguished University Professor Emeritus, along with Joshua J. Daymude, a postdoctoral research associate at Arizona State University, and Stephanie Forrest, professor of Computer Science at Arizona State University, explores ideological polarization and how it can become a runaway process in a new article published by the Proceedings of the National Academy of Sciences

The article, “Preventing extreme polarization of political attitudes,” defines ideological polarization as “the extent to which political views are dispersed.” To investigate it and its dangers, the authors develop an agent-based model (ABM). They also utilize an attraction-repulsion model (ARM). In their model, there are individual actors and rules. The rules include that actors tend to interact with those with similar views and that interactions between similar actors reduce their difference, while interactions between different actors increase their difference.

The authors point out a few particularities of their model: 1) Its simplicity represents opinion change based only on an individual’s attraction to or repulsion from others’ positions. 2) It avoids the assumption that the direction and magnitude of opinion change are correlated. 3) It includes discoveries, including conditions under which a population approaches convergence, or under which a few extremists can prevent polarization, and more. 

After analyzing their models results using these categories, they report their results through assessing six different categories: tolerance, or “the level of ideological difference that actors find attractive rather than repulsive; responsiveness, or how far actors move when another attracts or repulses them; exposure, or the amount a person is exposed to opinions that are different from their own; multiple ideological dimensions; economic self-interest, and how that affects the actor’s ideological position; and external shock, or events that exogenously shift actors’ ideological positions so that they become less polarized.

Then, the authors turn two to questions: Is there a level of ideological polarization above which polarization feeds upon itself to become a runaway process? And, if so, what policy interventions could prevent such dangerous positive feedback loops?

They confirm that there is a level of ideological polarization where it becomes a runaway process, which eventually leads to extremism. The biggest influence in this runaway polarization is intolerance, “especially when enhanced by high exposure that enables frequent repulsive interactions between dissimilar individuals,” the authors write. They go on to explain that this conclusion holds in other ideological dimensions. 

To answer their second question, the authors discuss how tolerance and responsiveness are inadequate policy interventions to prevent runaway polarization. Instead, exposure to dissimilar views works quite well. 

“Encouraging interactions among those with different views might be expected to decrease polarization by fostering increased tolerance. However, the ARM treats tolerance and exposure as independent features of a population,” they write. “If a population is stubbornly intolerant and on a trajectory to runaway polarization, low exposure decreases the probability of interactions between mutually intolerant groups. This, in turn, preserves ideological diversity by inhibiting repulsion.”

The authors also explore different ideological dimensions and external shocks as solutions, but neither work quite as well as exposure. 

They conclude by discussing how helpful the ARM is: “With just two simple rules, the ARM yields complex dynamics that provide policy-relevant insights into mechanisms for preventing extreme polarization.”

Read the entirety of the article, “Preventing extreme polarization of political attitudes,” here