Dual Process Theory and the
Political Belief Bias Effect
Makiah R. Nuutinen, Dane G. Wendell, Richard E. Matland, & Robert G. Morrison
● Decades of research in thinking and reasoning suggests that two competing
systems are frequently engaged to make decisions (Kahneman, 2011).
● Dual Process Theory (Evans, 2012) describes a relatively fast, less demanding
system based on prior knowledge and heuristics (type 1) and a slower, more
effortful, deliberative approach based on rational reasoning (type 2).
● Using syllogisms researchers have demonstrated situations where prior
knowledge (type 1) can conflict with reason (type 2) resulting in belief bias.
● A recent study by Pennycook et al. (2013) demonstrated that individuals with
strong religious beliefs are more likely to show belief bias when solving
syllogisms containing general knowledge that may conflict with prior beliefs.
● We explore this finding further and seek to examine how political conservatism,
often associated with cognitive rigidity (Jost & Amodio, 2012), may influence the
type of processing used to solve syllogisms varying in their political content.
● 900 participants recruited through Amazon’s Mechanical Turk completed an
online survey which asked questions about political ideology and knowledge,
religious belief, and demographics. Participants also completed a brief matrix
reasoning task to assess fluid intelligence.
● A randomly chosen subsample of 173 liberals and 118 conservatives
participated in a second survey session where they solved non-political and
● Participants judged the logical validity of 16 randomly ordered syllogistic
statement sets (see examples above). Half of the statement sets were non-
political and half of the statement sets were political.
● Political syllogisms were created based on widely held beliefs for conservatives
● In conflict trials, the participants’ underlying beliefs make solving the syllogism
correctly more difficult. In contrast, underlying beliefs aid in accurately solving
● After the syllogism task, participants independently judged the believability of all
16 syllogism conclusions. Believability ratings were used to sort political
syllogisms into conflict and non-conflict trials for each participant.
● Our results confirm that characteristics of respondents, in one case religiosity,
in the other case political conservatism, are associated with cognitive rigidity in
the context of syllogistic reasoning.
● Our results suggest that conservatives may have more difficulty inhibiting their
fast political knowledge system in order to employ the slow logical reasoning
system in the context of political information.
● In contrast, liberals may have a more flexible cognitive style, allowing them to
engage in analytic reasoning more readily.
● Future studies will use neuroimaging to examine the time course of processing
in liberals and conservatives to determine the mechanism responsible for the
The authors would like to thank the Loyola University Chicago Mulcahy and
Provost Fellowship Programs (MRN, RGM) as well as the Arthur J. Schmitt
Fellowship (DW) for their generous support.
Table 2 Regression analysis predicting political belief bias performance
p = .02
p = .65
p = .005
p = .63
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