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Sunday, December 13, 2020

Polarization and extremism emerge from rational choice

Kvam, P. D., & Baldwin, M. 
(2020, October 21).


Polarization is often thought to be the product of biased information search, motivated reasoning, or other psychological biases. However, polarization and extremism can still occur in the absence of any bias or irrational thinking. In this paper, we show that polarization occurs among groups of decision makers who are implementing rational choice strategies that maximize decision efficiency. This occurs because extreme information enables decision makers to make up their minds and stop considering new information, whereas moderate information is unlikely to trigger a decision. Furthermore, groups of decision makers will generate extremists -- individuals who hold strong views despite being uninformed and impulsive. In re-analyses of seven previous empirical studies on both perceptual and preferential choice, we show that both polarization and extremism manifest across a wide variety of choice paradigms. We conclude by offering theoretically-motivated interventions that could reduce polarization and extremism by altering the incentives people have when gathering information.


In a decision scenario that incentivizes a trade-off between time and decision quality, a population of rational decision makers will become polarized. In this paper, we have shown this through simulations, a mathematical proof (supplementary materials) and demonstrated it empirically in seven studies.   This  leads  us  to  an  unfortunate  but  unavoidable  conclusion that decision making is a bias-inducing process by which  participants  gather  representative  information  from their environment and, through the decision rules they implement, distort it toward the extremes. Such a process also generates extremists, who hold extreme views and carry undue influence over cultural discourse (Navarro et al.,2018) despite being relatively uninformed and impulsive (low thresh-olds;Kim & Lee,2011). We have suggested several avenues for interventions, foremost among them providing incentives favoring estimation or judgments as opposed to incentives for timely decision making. Our hope is that future work testing and implementing these interventions will reduce the prevalence of polarization and extremism across social domains currently occupied by decision makers.