Is political extremism supported by an illusion of understanding?

Polarization is rising in most countries in the West. How can we reduce it? One potential strategy is to ask people to explain how a political policy works-how it leads to consequences- because that has been shown to induce a kind of intellectual humility: Explanation causes people to reduce their judgments of understanding of the issues (their "illusion of explanatory depth"). It also reduces confidence in attitudes about the policies; people become less extreme. Some attempts to replicate this reduction of polarization have been unsuccessful. Is the original effect real or is it just a fluke? In this paper, we explore the effect using more timely political issues and compare judgments of issues whose attitudes are grounded in consequentialist reasoning versus protected values. We also investigate the role of social proof. We find that understanding and attitude extremity are reduced after explanation but only for consequentialist issues, not those based on protected values. There was no effect of social proof.