But that's because it's a difficult question. Or at least is if one treats it as one of "measurement" & "weight of the evidence." I remain convinced that it is not of great practical significance--that is, even if "motivated reasoning" and like dynamics are "asymmetric" across the ideological spectrum (or cultural spectra) that define the groups polarized on policy-consequential facts, the evidence is overwhelming and undeniable that members of all such groups are subject to this dynamic, & to an extent that makes addressing its general impact -- rather than singling out one or another group as "anti-science" etc. -- the proper normative aim for those dedicated to advancing enlightened self-govt.
But issues of "measurement" & "weight of the evidence" etc. are still, in my view, perfectly legitimate matters of scholarly inquiry. Indeed, pursuit of them in this case will, I'm sure, enlarge knowledge, theoretical and practical.
"Asymmetry" is an open question--& not just in the sense that nothing in science is ever resolved but in the sense that those on both "sides" (i.e., those who believe politically motivated reasoning is symmetric and those who believe it is asymmetric) ought to wonder enough about the correctness of their own position to wish that they had more evidence.
Here's an excerpt from my The Politically Motivated Reasoning Paradigm survey/synthesis essay addressing the state of the "debate":
4. Asymmetry thesis
The “factual polarization” associated with politically motivated reasoning is pervasive in U.S. political life. But whether politically motivated reasoning is uniform across opposing cultural groups is a matter of considerable debate (Mooney 2012).
In the spirit of the classic “authoritarian personality” thesis (Adorno 1950), one group of scholars has forcefully advanced the claim that it is not. Known as the “asymmetry thesis,” their position links biased processing of political information with characteristics associated with right-wing political orientations. Their studies emphasize correlations in observational studies between conventional ideological measures and scores on self-report reasoning-style scales such as “need for closure” and “need for cognition” and on personality-trait scales such “openness to experience” (Jost, Glaser, Kruglanski & Sulloway 2003; Jost, Hennes & Lavine 2013).
But the research that the “neo-authoritarian personality” school features supplies weak evidence for the asymmetry thesis. First, the reasoning style measures that they feature are of questionable validity. It is a staple of cognitive psychology that defects in information processing are not open to introspective observation or control (Pronin 2007) –a conclusion that applies to individuals high as well as more modest in cognitive proficiency (West, Meserve & Stanovich 2012). There is thus little reason to believe a person’s own perception of the quality of his reasoning is a valid measure of the same.
Indeed, tests that seek to validate such self-report reasoning style scales consistently find them to be inferior in predicting the disposition to resort to conscious, effortful information processing than performance-based measures such as the Cognitive Reflection Test and Numeracy (Toplak, West & Stanovich 2011; Liberali, Reyna, Furlan & Pardo 2011). Those measures, when applied to valid general population samples, show no meaningful correlation with party affiliation or liberal-conservative ideology (Kahan 2013; Baron 2015).
More importantly, there is no evidence that individual differences in reasoning style predict vulnerability to politically motivated reasoning. On the contrary, as will be discussed in the next part, evidence suggests that proficiency in dispositions such as cognitive reflection, numeracy, and science comprehension magnify politically motivated reasoning (Fig. 6).
Ultimately, the only way to determine if politically motivated reasoning is asymmetric with respect to ideology or other diverse systems of identity-defining commitments is through valid experiments. There are a collection of intriguing experiments that variously purport to show that one or another form of judgment—e.g., moral evolution, willingness to espouse counter-attitudinal positions, the political valence of positions formed while intoxicated, individual differences in activation of “brain regions” etc.—is ideologically asymmetric or symmetric (Thórisdóttir & Jost 2011; Jost, Nam, Jost & Van Bavel 2013; Eidelman et al. 2012; Crawford & Brandt 2013; Schreiber, Fonzo et al. 2013). These studies vary dramatically in validity and insight. But even the very best and genuinely informative ones (e.g., Conway, Gideon, et al. 2015; Liu & Ditto 2013; Crawford 2012) are in fact examining a form of information processing distinct from PMRP and with methods other than the PMRP design or its equivalent.
One study that did use the PMRP design found no support for the “asymmetry thesis” (Kahan 2013). In it, individuals of left- and right-wing political outlooks displayed perfectly symmetric forms of politically motivated fashioning in evaluating evidence that people who reject their group’s position on climate change have been found to engage in open-minded evaluation of evidence (Figure 5).
But that’s a single study, one that like any other is open to reasonable alternative explanations that themselves can inform future studies. In sum, it is certainly reasonable to view the “asymmetry thesis” issue as unresolved. The only important point is that progress in resolving it is unlikely to occur unless studied with designs that reflect PMRP design or ones equivalently suited to support inferences consistent with the PMRP model.
Adorno, T.W. The Authoritarian personality (Harper, New York, 1950).
Baron, J. Supplement to Deppe et al.(2015). Judgment and Decision Making 10, 2 (2015).
Conway, L.G., Gornick, L.J., Houck, S.C., Anderson, C., Stockert, J., Sessoms, D. & McCue, K. Are Conservatives Really More Simple‐Minded than Liberals? The Domain Specificity of Complex Thinking. Political Psychology (2015), advance on-line, DOI: 10.1111/pops.12304.
Crawford, J.T. The ideologically objectionable premise model: Predicting biased political judgments on the left and right. Journal of Experimental Social Psychology 48, 138-151 (2012).
Eidelman, S., Crandall, C.S., Goodman, J.A. & Blanchar, J.C. Low-Effort Thought Promotes Political Conservatism. Pers. Soc. Psychol. B. (2012).
Jost, J.T., Glaser, J., Kruglanski, A.W. & Sulloway, F.J. Political Conservatism as Motivated Social Cognition. Psychological Bulletin 129, 339-375 (2003).
Jost, J.T., Hennes, E.P. & Lavine, H. “Hot” political cognition: Its self-, group-, and system-serving purposes. in Oxford handbook of social cognition (ed. D.E. Carlson) 851-875 (Oxford University Press, New York, 2013).
Liberali, J.M., Reyna, V.F., Furlan, S., Stein, L.M. & Pardo, S.T. Individual Differences in Numeracy and Cognitive Reflection, with Implications for Biases and Fallacies in Probability Judgment. Journal of Behavioral Decision Making 25, 361-381 (2012).
Nam, H.H., Jost, J.T. & Van Bavel, J.J. “Not for All the Tea in China!” Political Ideology and the Avoidance of Dissonance. PLoS ONE 8(4) 8, :e59837. doi:59810.51371/journal.pone.0059837 (2013).
Pronin, E. Perception and misperception of bias in human judgment. Trends in cognitive sciences 11, 37-43 (2007).
Thórisdóttir, H. & Jost, J.T. Motivated Closed-Mindedness Mediates the Effect of Threat on Political Conservatism. Political Psychology 32, 785-811 (2011).
Toplak, M., West, R. & Stanovich, K. The Cognitive Reflection Test as a predictor of performance on heuristics-and-biases tasks. Memory & Cognition 39, 1275-1289 (2011).
West, R.F., Meserve, R.J. & Stanovich, K.E. Cognitive sophistication does not attenuate the bias blind spot. Journal of Personality and Social Psychology 103, 506 (2012).