The case for partisan motivated reasoning

A large body of research in political science claims that the way in which democratic citizens think about politics is motivationally biased by partisanship. Numerous critics argue that the evidence for this claim is better explained by theories in which party allegiances influence political cognition without motivating citizens to embrace biased beliefs. This article has three aims. First, I clarify this criticism, explain why common responses to it are unsuccessful, and argue that to make progress on this debate we need a more developed theory of the connections between group attachments and motivated reasoning. Second, I develop such a theory. Drawing on research on coalitional psychology and the social functions of beliefs, I argue that partisanship unconsciously biases cognition by generating motivations to advocate for party interests, which transform individuals into partisan press secretaries. Finally, I argue that this theory offers a superior explanation of a wide range of relevant findings than purely non-motivational theories of political cognition.


Introduction
How should we understand the psychology of political cognition?Specifically, how do citizens think and reason about those aspects of the world-the economy, the behaviour of politicians, the state of society, and so on-that are relevant to democratic decision making?According to one influential theory, citizens are frequently biased in how they think about politics by partisanship.That is, support for political parties motivates people to embrace biased beliefs-typically beliefs that reflect Synthese (2023) 202:89 favourably on such parties-and so powerfully distorts the processes by which they seek out and process political information (Achen & Bartels, 2016;Brennan, 2016;Campbell et al. 1960;Kahan, 2017;Mason, 2018).Such motivated irrationality is then thought to underlie or at least exacerbate numerous social and political problems, including various forms of political polarisation (Finkel, et al., 2020;Marietta & Barker, 2019;Mason, 2018) and costly group-based misinformation (Ditto, Liu, et al., 2019;Kahan, 2017;Williams, 2021b).I will henceforth refer to this view as the Partisan Bias Hypothesis.
The Partisan Bias Hypothesis is extremely influential (Achen & Bartels, 2016;Bisgaard, 2019;Ditto, et al., 2019a;Federico & Malka, 2021;Kahan, 2017;Mason, 2018).It is also controversial.According to one leading critique, findings advanced as evidence for the hypothesis are consistent with theories in which party allegiances influence political cognition without motivating citizens to embrace biased beliefs (Bullock, 2009;Druckman & McGrath, 2019;Lepoutre, 2020;Levy, 2019Levy, , 2021b;;Singer, et al., 2019;Tappin, et al., 2020).For example, perhaps party allegiances influence what citizens believe simply because supporters of different parties tend to have different experiences, inhabit different social networks, and more generally encounter different information (Lepoutre, 2020;Pennycook, et al., 2022).Or perhaps party allegiances influence what citizens believe simply because supporters of different parties tend to trust different information sources (Levy, 2021b;Nguyen, 2020;Sniderman, et al., 1993;Weatherall & O'Connor, 2021).Or perhaps party allegiances only appear to influence what citizens believe because supporters of different parties tend to hold different beliefs about the world in general-different "priors" in Bayesian parlance (see § 3 below)-and rationally interpret novel information in light of these divergent beliefs (Druckman & McGrath, 2019;Tappin, et al., 2020).Or perhaps it is a confluence of all these factors and more.Importantly, this critique is bolstered by research showing that partisans are not as dogmatic as some earlier findings seemed to suggest (e.g., Lord, et al., 1979;Nyhan and Reifler, 2010), and can in fact revise even strongly-held political beliefs when presented with contrary evidence and counter-arguments (Coppock, 2023;Nyhan, 2021;Tappin, et al., 2023).
I have several aims in this article.After reviewing evidence that party allegiances influence political beliefs ( § 2) and clarifying the question of whether this influence involves motivated cognition ( § 3), I will describe the competing answers given to this question in the scientific literature ( § 4).I will argue that one important reason why this disagreement has been so difficult to resolve is the absence of a welldeveloped theory for understanding the relationship between group attachments and motivated cognition ( § 5).My second aim is to outline such a theory ( § 6).Drawing on research on coalitional psychology (Boyer, 2018;Marie & Petersen, 2022;Tooby & Cosmides, 2010) and the social functions of beliefs and reasoning (Funkhouser, 2017;Mercier & Sperber, 2017;Tetlock, 2002a;von Hippel & Trivers, 2011;Williams, 2021b), I will argue that party allegiances unconsciously bias cognition by generating motivations to advocate for party interests, which transform citizens into automatic partisan press secretaries.My final aim is then to argue that this theory provides a superior explanation of a wide range of relevant findings than alternative non-motivational theories of political cognition ( § 7).
1 3 2 Democratic group cognition I will use the term "group cognition" to describe the fact that what democratic citizens believe in politics is heavily influenced by group allegiances (Achen & Bartels, 2016;Brennan, 2021;Lepoutre, 2020). 1 This characterisation therefore leaves open what form this influence takes and the causal pathways through which it operates.Before turning to such controversies, I will first clarify the phenomenon and highlight some of the evidence for it.
A useful way of understanding group cognition is by contrasting it with an alternative "folk theory" of democracy (Achen & Bartels, 2016).On this theory, citizens have well-informed policy preferences, which are grounded in their values and ideological commitments, and they vote for candidates and parties that best match these independently-formed preferences.There is overwhelming evidence that this theory is mistaken (Achen & Bartels, 2016;Brennan, 2021;Finkel, et al., 2020;Mason, 2018).Most citizens are extremely low in political interest and knowledge.Their expressed views on policy questions are shallow and inconsistent: not only do they vary in accordance with seemingly minimal variation in question wording or context, but even successive responses to the same question are frequently different (Achen & Bartels, 2016;Brennan, 2021).Summarising such findings over half a century ago, Converse (1964, p.245) thus concluded that most citizens are "innocent of ideology" and "do not have meaningful beliefs, even on issues that have formed the basis for intense political controversy among elites for substantial periods of time."Instead, what seems to drive most citizens' political behaviour is not well-informed policy preferences but group affiliations, such that "for most people, most of the time, party and group loyalties are the primary drivers of vote choice" (Achen & Bartels, 2016, p.299).Specifically, group attachments-for example, attachments to races, religions, social classes, subcultures, and so on-frequently influence party affiliations, which are then highly stable and guide voting behaviour (Achen & Bartels, 2016;Brennan, 2021;Mason, 2018).
A significant minority of citizens is much higher in political engagement.They have much greater political knowledge and hold more stable beliefs that are more consistently aligned with the dominant ideological packages of the time (Converse, 1964;Federico & Malka, 2021).Importantly, however, their attitudes and behaviours appear to be even more influenced by party allegiances (Brennan, 2021;Hannon, 2022).For example, they more strongly identify with political parties, and their beliefs-even on seemingly straightforwardly factual issues-are highly correlated with their partisan identities (Achen & Bartels, 2016;Federico & Malka, 2021;Joshi, 2020).Further, there is extensive evidence that such beliefs are much "more often an effect of partisanship than its cause" (Achen & Bartels, 2016, p.234;see Brennan, 2021;Campbell, et al., 1960;Cohen, 2003;Federico and Malka, 2021).In addition to experimental confirmations of this causal influence (e.g., Barber and Pope, 2019;Cohen, 2003), for example, panel data demonstrate that citizens adjust their beliefs to align with their partisan identities (Layman & Carsey, 2002), in some cases substan-tially and rapidly revising their beliefs when their party switches positions (Slothuus & Bisgaard, 2021).
In general, then, political cognition appears to be strongly influenced by party allegiances.The primary form of group cognition that I will focus on in what follows is therefore what I will call "partisan cognition".Nevertheless, given important differences between citizens, it is not obvious that partisan cognition takes the same form in all cases.As noted, for example, it is plausible that those low in political engagement do not even hold substantive normative and empirical political beliefs on most topics (Achen & Bartels, 2016;Converse, 1964;Hannon, 2021).Moreover, not only are the opinions that they express in surveys highly variable over time, but there is often surprisingly little disagreement in such opinions across different parties, suggesting that partisan cognition for such citizens largely manifests in voting choices, expressive behaviours, and negative feelings towards political outgroups (Finkel, et al., 2020;Hanson, 2021;Mason, 2018).Given that my aim in what follows is to explore how partisan allegiances shape belief formation, I will therefore primarily focus on citizens high in political engagement.

Is partisan cognition motivated cognition? clarifying the question
According to numerous theorists, partisan cognition manifests a kind of bias: it involves the distorting influence of partisan allegiances on cognitive processes (Brennan, 2016;Hannon, 2022;Kahan, 2017;Mason, 2018;Somin, 2006;Williams, 2021b).In technical terms, this perspective is typically understood in terms of directionally motivated reasoning (henceforth just "motivated reasoning"), which occurs when beliefs are unconsciously biased away from accuracy by "directional goals", so-called because they direct cognition towards conclusions that are favoured for reasons independent of their evidential support (Kunda, 1990).The psychological literature documents numerous examples of such directional goals, including emotion regulation, identity expression, and self-aggrandisement (Kahan, 2017;Kunda, 1990;Williams, 2021c).It also documents numerous biases in how individuals gather, evaluate, and recall evidence through which such goals bias cognition, including selective exposure (i.e., selectively exposing oneself to confirmatory evidence); biased evaluation (i.e., selectively applying lower evidential standards to confirmatory evidence than to disconfirmatory evidence); selective forgetting (i.e., selectively encoding and retrieving confirmatory memories); and more (Epley & Gilovich, 2016).Because many of these biases involve cognitive processes that go beyond explicit reasoning-in the language of dual systems theory, they implicate "type 1" processing (Kahneman, 2003)-a more accurate name for motivated reasoning is "motivated cognition," which is the term that I will use in what follows.
The controversy that I am concerned with in this article is whether partisan cognition involves motivated cognition.Thus, on one side of this controversy theorists view party allegiances as a powerful source of directional goals-goals such as expressing group allegiances and viewing one's ingroup favourably-that unconsciously bias how citizens think and reason about politics (e.g., Bisgaard, 2019;Kahan, et al., 2017;Mason, 2018).On the other side theorists argue that party allegiances influence 1 3 political cognition through processes such as divergent information exposure and heightened trust in co-partisans that are consistent with purely accuracy-motivated cognition (e.g., Levy, 2021b;Pennycook, et al., 2022;Singer, et al., 2019).
Before exploring this disagreement, several important clarifications are necessary.First, what I have called the two "sides" of the controversy are obviously just the extreme points on a continuum ranging over many possible views on the degree to which partisan cognition involves motivated cognition.At least in initially characterising the controversy, however, it will often be convenient to write as if there are only two positions (see § 8).
Second, debates about the Partisan Bias Hypothesis are often framed in terms of whether partisan cognition is rational (Levy, 2021b).This question is related to but importantly different from the question of whether it involves motivated cognition.
To begin with, it is important to distinguish epistemic rationality, which concerns whether individuals form beliefs in ways that are sensitive to available evidence, from instrumental rationality, which concerns whether actions promote the practical goals of the relevant agent (Bortolotti, 2015).Not only are these two forms of rationality distinct, but many proponents of the Partisan Bias Hypothesis view partisan cognition as an instrumentally rational form of epistemic irrationality (Brennan, 2016;Somin, 2006;Williams, 2021b).It is instrumentally rational, they argue, because while there is typically little advantage to being well-informed in politics, partisan bias often yields considerable emotional, social, and even material benefits.
Given this, the main area of disagreement concerns whether partisan cognition is epistemically rational.This raises the difficult question of how to understand epistemic rationality, however.One common approach in psychology appeals to formal models of rationality such as logic and probability theory (Kahneman, et al., 1982).For example, theorists often appeal to Bayesian inference as the benchmark against which to evaluate whether group cognition is epistemically rational (Bullock, 2009;Dorst, 2022;Levy, 2021a;Stanovich, 2021;Tappin, et al., 2020).In Bayesian inference, the probability assigned to a hypothesis when exposed to new evidence (its posterior probability) is proportional to how well the hypothesis predicts the evidence (its likelihood) weighted by the probability of the hypothesis prior to receiving the evidence (its prior probability).It derives from Bayes' theorem, a derivation of probability theory which can be stated as follows when applied to hypothesis updating: Importantly, the question of whether partisan cognition involves motivated cognition is different from the question of whether it is consistent with Bayesian inference.Specifically, if group cognition involves motivated cognition, it involves a departure from Bayesian inference (see § 4 below), 2 but group cognition might depart from Bayesian inference for reasons independent of motivated cognition.Human cognition routinely falls short of optimal epistemic rationality for a range of non-motivational reasons (Kahneman, 2003;Sniderman, et al., 1993), and many alternatives to the Partisan Bias Hypothesis describe partisan cognition in terms of fast and frugal cognitive heuristics, not the use of computationally expensive Bayesian updating (Sniderman, et al., 1993).
Given that my focus in what follows is on the question of whether partisan cognition involves motivated cognition, I will therefore explore the potentially Bayesian character of partisan cognition only insofar as it is relevant to answering this question (see § 4 below).Not only is this the question that most theorists in the relevant socialscientific literature attempt to address (Kahan, 2017;Pennycook, et al., 2022;Tappin, et al., 2020;Williams, 2021c), but it also seems to have the greater importance.To the extent that partisan cognition involves motivated cognition, this has pessimistic implications for our understanding of public discourse and democratic accountability, implying that citizens routinely subordinate the pursuit of truth to practical goals rooted in partisan allegiances (Achen & Bartels, 2016;Bisgaard, 2019;Brennan, 2016;Hannon, 2022;Somin, 2006;Williams, 2021c).To the extent that partisan cognition involves the genuine and disinterested pursuit of truth, in contrast, this seems to have far more optimistic implications when it comes to our collective capacities to address misinformation, respond to rational persuasion, and converge on the facts, and these more optimistic implications hold even if citizens are not ideal Bayesian reasoners (Federico & Malka, 2021;Lepoutre, 2020;Pennycook & Rand, 2019;Tappin, et al., 2020).

Is partisan cognition motivated cognition? the current debate
In this section, I will review the kinds of observational and experimental evidence that proponents of the Partisan Bias Hypothesis typically appeal to in its defence, and I will explain why critics argue that such evidence is consistent with-and perhaps better explained by-theories of partisan cognition in which motivated cognition plays no role.

Observational findings
Supporters of different political parties often express different factual beliefs about a range of social, economic, and cultural phenomena: the state of the economy and direction of economic growth; the rate and effects of immigration; the existence or non-existence of societal threats such as climate change; the degree to which race determines life outcomes; the extent to which recent elections were undermined by electoral fraud; and so on (Ditto, Liu, et al., 2019;Finkel, et al., 2020;Kahan, et al., 2017;Marietta and Barker, 2019;Nyhan, 2020).Moreover, such beliefs are not only frequently inaccurate and at odds with widely accessible evidence; they are also placed on new information (i.e., their likelihoods) based on its alignment with non-epistemic goals (Williams, 2021d).rationally orthogonal (Joshi, 2020).For example, in the USA a partisan's beliefs about abortion are predictive of their beliefs about climate change, the effects of minimum wage policy, and a range of other economic and cultural phenomena, even though there is no obvious rational relationship between such beliefs.Instead, the packages of beliefs that get bundled with any political party at a given time largely reflect the practicalities of coalition formation and the strategic activity of elites (Federico & Malka, 2021;Groenendyk, et al., 2022;Stanovich, 2021).
To many, findings such as this strongly suggest that partisan cognition involves motivated cognition: in holding a package of rationally orthogonal beliefs that are often inaccurate and at odds with widely available evidence, citizens are assumed to be subordinating the pursuit of truth to non-epistemic concerns such as ingroup favouritism and loyalty (Brennan, 2016;Joshi, 2020;Nyhan, 2020;Stanovich, 2021;Williams, 2021c).
As several theorists have pointed out, however, this inference is too quick.At best, these findings demonstrate that what people believe is heavily influenced by party affiliation.There are many reasons why belief formation might be influenced by group identities such as partisan affiliations that have nothing to do with motivated cognition, however.For example, supporters of different parties often have different experiences, inhabit different social networks, and more generally encounter different information, including different forms of misinformation and disinformation (Lepoutre, 2020;Pennycook, et al., 2022).Thus, the correlations between partisan identities and beliefs might simply reflect exposure to different information, and false beliefs might simply reflect exposure to false or misleading information.In fact, there are modelling results demonstrating that substantial polarisation in what different groups believe can emerge under conditions in which their members are solely motivated by accuracy (Benoît & Dubra, 2019;O'Connor & Weatherall, 2019;Singer, et al., 2019;Weatherall & O'Connor, 2021).Moreover, a growing body of research shows that citizens are in fact capable of abandoning partisan beliefs when presented with counter-evidence and persuasive arguments (Nyhan, 2021;Tappin, et al., 2023), which suggests that such beliefs typically arise not because citizens bury their heads in the sand but because of exposure to selective information.
This response leads to a second argument that theorists often appeal to in defence of the Partisan Bias Hypothesis: namely, that insofar as partisans actively seek out evidence and arguments from different information sources (e.g., different political elites or media) that are biased in favour of different parties, this reflects a kind of selective exposure whereby citizens are motivated to seek out information that confirms politically congenial beliefs (Iyengar & Hahn, 2009;Williams, 2022).Once again, however, any direct inference of motivated cognition from the fact that people seek out information from ideologically congruent sources is unwarranted.There are many reasons why people might seek out information from partisan sources.For example, it might reflect a rational disposition to assign greater trustworthiness to those who share the same beliefs (Tappin, et al., 2020) or a truth-seeking tendency to defer to ingroup members on the grounds that they share your values and so are less likely to deceive you (Levy, 2019).
More generally, we are completely dependent on trust in forming beliefs about almost all political topics.When it comes to complex policy questions or politi-cally relevant scientific issues such as climate change, for example, most citizens do not just lack access to the evidence that bears directly on the question but lack the knowledge and skills to even understand the evidence (Levy, 2021b).Coupled with divergent estimations of the trustworthiness of different information sources, this dependence on trust can therefore easily drive polarisation and false beliefs even in the face of widely available contrary evidence (Nguyen, 2020).For example, if the evidence for climate change is disseminated by liberal scientists that conservatives view as untrustworthy and challenged by right-wing pundits that they view as reliable, being conservative might come to be associated with climate change denialism for reasons independent of motivated cognition (Druckman & McGrath, 2019;Levy, 2021b;Tappin, et al., 2020).Moreover, this point is strengthened once one recalls that critics of the Partisan Bias Hypothesis need not claim that group cognition involves optimal epistemic rationality.That is, not only do supporters of different parties encounter different information and trust different information sources, but through both carelessness and cognitive limitations they no doubt also fall prey to various "cold" (i.e., non-motivated) inferential errors (Kahneman, 2003;Pennycook & Rand, 2019;Sniderman, et al., 1993).
Stepping back, then, the basic problem with appeals to many observed psychological findings in this area is that such phenomena appear to be consistent with both motivational and non-motivational explanations.Given this, it is plausible to think that the way to adjudicate between these competing explanations is to turn to experiments that can probe for the causal mechanisms underlying partisan cognition.

Experimental findings
There is a large experimental literature that purports to demonstrate that what people are motivated to believe based on their partisan identities influences how they interpret, evaluate, and process information (Bisgaard, 2019;Ditto, et al., 2019a;Kahan, et al., 2017).For example, in a recent meta-analysis including fifty-one experiments with over eighteen thousand participants, Ditto et al. (2019, p.274) argue that there is strong evidence for partisan bias in how both Democrats and Republicans in the USA handle information, where they define "partisan bias" as the "general tendency for people to think or act in ways that unwittingly favor their own political group or cast their own ideologically based beliefs in a favorable light."To probe for this bias, their meta-analysis includes studies that ask experimental subjects to evaluate what they call "matched information…that is as identical as possible in every way except that in one case it favors the participant's political affinities… and in the other it challenges those affinities" (Ditto, Liu, et al., 2019, p.274).Given this, I will refer to such studies as employing matched-information designs.
Here are some examples of the kinds of experimental results that Ditto et al. ( 2019) include in their meta-analysis: • Influential "party cue" designs (Tappin, et al., 2020) demonstrate that participants are more likely to endorse a policy if told that their party supports it, in some cases endorsing policies that they would otherwise oppose because of their association with party endorsement (Cohen, 2003;see Finkel, et al., 2020).
• Kahan et al. (2012) show that liberals and conservatives form different judgements about identical protest behaviour-for example, about whether the protestors obstruct and threaten pedestrians-depending on whether the protest is described as being pro-life or pro-gay rights.
• Several experiments demonstrate that people evaluate the quality of otherwise identical studies more favourably when they support their strongly-held political views (e.g., Lord, et al., 1979;Taber and Lodge, 2006).• Kahan et al. (2017) find that partisans who can correctly interpret quantitative information when framed in terms of the effects of skin cream are less capable of interpreting identical quantitative information when it is framed as challenging their attitudes about gun control.
Such experimental findings thus appear to show that how people interpret, evaluate, and process information depends on the congeniality of that information to their partisan allegiances.That is, they seem to provide strong evidence for the existence of partisan motivated cognition (Ditto, Liu, et al., 2019;Kahan, et al., 2017).
Once again, critics have argued that this interpretation is misguided.The basic problem is that the conclusions that partisans are assumed to be motivated to reach in such experiments correlate with what they in fact believe (Stanovich, 2021;Tappin, et al., 2020).Thus, when you vary the implications of otherwise identical information for such desired conclusions, you also vary the background beliefs that participants bring to bear in interpreting that information.However, what one believes influences how one processes information for reasons independent of motivated cognition.Thus, the results of matched-information designs appear to be consistent with purely cognitive explanations in which beliefs are influenced by other beliefs in the absence of any motivational biases.
Consider some of the experimental results just described, for example.First, as has long been noted (Sniderman, et al., 1993), the results of party cue designs might simply reflect people's divergent beliefs about the trustworthiness of different parties.That is, if you trust your political party's judgement, you will defer to this judgement in the absence of motivated cognition.
Second, Kahan et al.'s (2012) finding about how partisans interpret protest behaviour might simply reflect the influence of strong prior beliefs that co-partisans are more virtuous than opposing partisans (Baron & Jost, 2019;Tappin, et al., 2020).As noted above ( § 3), it is a basic tenet of Bayesian inference that how one responds to evidence should factor in one's prior beliefs, and strong beliefs about the relative virtues and characteristics of different kinds of protestors will inevitably colour how one perceives their behaviour.
Third, the fact that people evaluate the quality of otherwise identical studies more favourably when they support their political views is consistent with non-motivated cognition (Stanovich, 2021;Tappin, et al., 2020).Given uncertainty about the reliability of the source of information, even optimally rational agents will draw upon their prior beliefs to evaluate the reliability of that information.There are formal arguments demonstrating this (Coppock, 2023;Koehler, 1993), but the underlying idea is intuitive: scientists, for example, should be more sceptical of studies purporting to undermine well-established scientific claims.In fact, divergent prior beliefs alone can even give rise to the phenomenon of belief polarisation, which occurs when individuals with opposed beliefs increase their confidence in such beliefs-and thus polarise even further-when exposed to the same body of mixed evidence (Lord, et al., 1979;Taber & Lodge, 2006).Although this phenomenon is often taken as extremely strong evidence of motivated irrationality (e.g., Lord, et al., 1979Lord, et al., , p.2106)), Benoît and Dubra (2019) demonstrate that this intuition is mistaken: belief polarisation can occur under conditions in which people are solely motivated by accuracy, and experimental research into the phenomenon provides no reason to believe that such conditions do not obtain.
Finally, the fact that people's strong beliefs about a topic such as gun control interfere with their ability to rationally evaluate arguments and data in tension with such beliefs need not reflect any motivational bias.Human cognition is susceptible to belief bias, a purely cognitive tendency in which people find it difficult to rationally evaluate arguments whose conclusions challenge their beliefs (Tappin, et al., 2020).Thus, people are more likely to judge otherwise identical arguments as valid (or invalid) when they agree (or disagree) with their conclusions, including when it comes to neutral conclusions such as "Roses are living things" and "Mice are insects" (Stanovich, 2021).
Given this, experimental results widely believed to demonstrate partisan motivated cognition appear to be consistent with non-motivational explanations in which, as Baron and Jost (2019, p.296) put it, "the true source of the alleged bias… [is] purely cognitive, with no motivation involved-that is, purely a case of beliefs affecting beliefs rather than desires affecting beliefs." In response to this argument, some proponents of the existence of partisan motivated cognition concede that the experiments are consistent with purely beliefbased (i.e., cognitive) explanations but argue that the prior beliefs themselves result from motivated cognition.For example, Stanovich (2021) suggests that the results of matched-information designs often reflect motivated cognition (what he calls "myside bias") not because of the cognitive processing within the experiments but because the divergent priors that underlie such processing reflect what the participants are motivated to believe.
The basic problem with this response is that the experiments provide no insight into the origins of the beliefs that people bring to them.Thus, Stanovich's suggestion that such beliefs result from motivated cognition might be true, but it is not something that can be determined by the experiments.Given that the experiments are often cited as the chief source of evidence for partisan motivated cognition, it is difficult to see what is supposed to justify the suggestion.As we have seen ( § 4.1), the mere fact that partisans hold divergent and sometimes inaccurate beliefs is insufficient: even optimally rational truth-seeking agents can end up with divergent and inaccurate beliefs if exposed to selective and misleading information from trusted sources, and critics of the Partisan Bias Hypothesis need not think that people are optimally rational in this sense anyway.

Summary
In summary, even though the Partisan Bias Hypothesis seems to be vindicated by a wide range of observational and experimental findings, such findings appear to be consistent with non-motivational explanations.Importantly, this basic situation is not new.It reflects one of the oldest methodological problems in social psychology: namely, that even though there is a broad consensus among psychologists that motivated cognition is widespread, it has proven remarkably difficult to experimentally vindicate its existence in ways that clearly rule out alternative non-motivational explanations (see Kunda, 1990;Stanovich, 2021;Tetlock and Levi, 1982).In this specific case, however, non-motivational explanations are bolstered by a wealth of findings showing that citizens are not the dogmatic partisans that some earlier research seemed to suggest: far from simply clinging to partisan beliefs-or even doubling down (Nyhan & Reifler, 2010)-when such beliefs are challenged, people are capable of changing their minds in response to contrary evidence and persuasive arguments, even when such evidence and arguments reflect unfavourably on their side (Bisgaard, 2019;Coppock, 2023;Nyhan, 2021;Tappin, et al., 2023).
Stepping back, we therefore find ourselves in the following situation.On the one hand, a large body of research in political science and the social sciences more broadly assumes that partisan cognition involves motivated cognition and draws on this assumption to generate a wide range of conclusions about the nature of democracy and the limitations of democratic accountability (Brennan, 2016;Hannon, 2022;Kahan, et al., 2017;Somin, 2006;Williams, 2021c).As we have seen, however, the evidence base for this assumption appears to be weak.

Making progress
How should we make progress in this debate?Most obviously, if the problem with existing experimental research is that prior beliefs are confounded with conclusions that partisans are motivated to reach, scientists could develop better experimental designs that can discriminate between their effects.For example, this might include running experiments in which participants lack prior beliefs about the topic altogether, extracting people's prior beliefs in such a way as to rule out their influence in driving observed outcomes, or intervening directly on directional goals (Tappin, et al., 2020).
Such experimental innovations are important, and recent experiments that attempt to disentangle the effects of prior beliefs from directional goals appear to find compelling evidence in favour of the existence of partisan motivated cognition (Thaler, 2022).Nevertheless, new experimental designs are not a panacea.A lesson from nearly a century of psychological research is that it is extremely difficult to conclusively rule out the possibility of non-motivational explanations of experimental results (Kunda, 1990;Tetlock & Levi, 1982).If one is sufficiently creative in the beliefs and expectations that one attributes to experimental participants, even forms of informational sampling and processing that seem highly biased can be interpreted as purely accuracy-motivated cognition, and it is difficult to find decisive evidence against such attributions, especially given that non-motivational explanations need not posit ideal epistemic rationality.
Of course, a natural response to this worry is that the question is not whether nonmotivational explanations can be fitted to experimental results post hoc but whether such explanations are plausible.This is obviously correct.Although many commentators on this debate have argued that the controversy has reached an impasse due to the problem of "observational equivalence" (Bullock, 2009;Druckman & McGrath, 2019;Tappin, et al., 2020)-that is, the fact that motivational and non-motivational theories of political cognition are consistent with empirical findings-observational adequacy in this sense is not the sole aim of scientific explanation.Instead, scientific theories should be evaluated based on a range of criteria such as their simplicity, their coherence with well-established theories and results elsewhere in science, their ability to unify diverse findings and illuminate subtle patterns in those findings, and their fruitfulness in generating surprising predictions (Lipton, 2003;Newton-Smith, 1981).When considering such richer forms of theory evaluation, the fact that one can construct non-motivational theories of observed patterns and experimental results is insufficient for establishing the plausibility of such theories.
Here, however, a problem arises: for richer forms of theory evaluation to be possible, well-developed theories are necessary.When it comes to the Partisan Bias Hypothesis, however, we seem to lack such a theory.Thus, in their critique of the hypothesis, Tappin et al. (2020, p.85) complain that evaluating the hypothesis is hampered by what they call its "conceptual imprecision".We see this imprecision in Ditto and colleague's (2019, p.274) schematic definition of partisan bias as the "general tendency for people to think or act in ways that unwittingly favor their own political group or cast their own ideologically based beliefs in a favorable light."Although this definition captures something important (see § 7), it is left unspecified what it means to unwittingly favour one's political group, what drives this bias, and what precise phenomena its existence predicts.
The main attempt to provide such a theory in this area comes from social identity theory (Achen & Bartels, 2016;Mason, 2018;Tajfel, 1974).At its core, social identity theory claims that ingroup biases result from processes of social identification in which an individual treats their membership of a group as central to their self-image.Because of an allegedly basic desire to maintain a positive self-image, this identification then drives ingroup favouritism and-at least under conditions of intergroup competition-prejudiced views of rival outgroups (Tajfel, 1974(Tajfel, , 1982)).In more recent research, theorists have argued that social identification and its associated tendencies also serve other putatively basic psychological needs, such as belonginess and certainty (see Mason, 2018).
Research within the tradition of social identity theory has been valuable in documenting a range of groupish psychological tendencies and various modulators of those tendencies (Huddy, 2001;Mason, 2018;Tajfel, 1982).As a theory of group psychology, however, it is inadequate for two fundamental reasons.First, it explains ingroup biases by appeal to their psychological benefits.Such explanations are at best merely proximate explanations: even if it is true that ingroup biases produce intrapsychic benefits, why is the mind configured in such a way that this is true?From an evolutionary perspective, outcomes that solely concern the individual's own 1 3 subjective experience are irrelevant to fitness (Kurzban, 2011;Mercier & Sperber, 2017;von Hippel & Trivers, 2011).Moreover, even setting aside such evolutionary considerations, ingroup biases and intergroup psychology are manifestly related to concrete social and material goals in ways that social identity theory does not capture or explain (Cikara, 2021).
Second, the putatively basic "psychological needs" posited by proponents of social identity theory fail to predict much of what we observe when it comes to group cognition, both in politics and more generally.As I return to below ( § 7), for example, the idea that ingroup biases are driven by psychological benefits fails to explain the fact that partisans are often biased towards beliefs that they do not want to be true and that they find distressing, or why there appear to be significant evidential constraints on what partisans can convince themselves of.
What's needed, then, is a superior theory.In the remainder of this article, I will begin to sketch such a theory.Of course, this sketch can only be preliminary.Nevertheless, I will outline just enough of the theory and its theoretical attractions to demonstrate how a combination of better-developed theories with richer forms of theory evaluation can help to advance the debate.
The theory builds on existing work on politically motivated cognition (e.g., Ditto, et al., 2019a, b;Kahan, 2017;Kahan, et al., 2017;Kunda, 1990;Taber and Lodge, 2006) but situates such work in a deeper theoretical framework rooted in coalitional psychology (Boyer, 2018;Cikara, 2021;Petersen, 2020;Pietraszewski, et al., 2015;Tooby & Cosmides, 2010) and the social functions of beliefs and reasoning (Butterworth, et al., 2022;Clark, et al., 2019;Funkhouser, 2017Funkhouser, , 2022;;Haidt, 2001;Hoffman & Yoeli, 2021;Mercier, 2020;Mercier and Sperber, 2017;Pinsof, et al., 2023;Simler and Hanson, 2016;Tetlock, 2002a;von Hippel and Trivers, 2011;Williams, 2021b).In this theory, party allegiances generate motivations to advocate for party interests.Such advocacy goals then drive powerful forms of motivated cognition, transforming citizens into partisan press secretaries in ways that unconsciously bias how they seek out, interpret, and process political information.This simple idea, I will argue, aligns with a large body of existing research on group psychology and biased beliefs, and it parsimoniously explains a wide range of relevant findings when it comes to partisan cognition.I will first motivate and describe the theory (S6) and then highlight its explanatory power over purely non-motivational theories of partisan cognition (S7).

Coalitional press secretaries
Human beings are groupish (Boyer, 2018;Tajfel, 1982).People form strong attachments to groups of diverse kinds: bands, tribes, nations, religions, unions, businesses, subcultures, political parties, and so on.Such attachments are in turn typically associated with a cluster of co-occurring groupish psychological tendencies: for example, a tendency to sharply distinguish ingroup (us) from outgroup (them); numerous ingroup biases, including not just ingroup favouritism but greater trust in and empathy for ingroup members over outsiders; the internalisation of costs and benefits to the group and motivations to advance its relative status; the experience of emotions such as pride, shame, and anger on behalf of the group; and much more (Boyer, 2018;Mason, 2018;Tooby & Cosmides, 2010).As noted, social identity theory understands such tendencies in terms of intrapsychic processes of social identification and their subjective benefits (Mason, 2018;Tajfel, 1982).From a deeper functional perspective, however, a significant body of empirical research demonstrates: first, that groups are typically treated by those who identify with them as coalitions, bounded collectives that cooperate and coordinate to promote shared interests; and second, that much of group psychology involves motivations and capacities specialised for navigating a world of such coalitions, enabling us to detect, form, join, support, defend, defect from, and compete against them (Boyer, 2018;Cikara, 2021;Petersen, 2020;Pietraszewski, et al., 2015;Pinsof, et al., 2023;Tooby & Cosmides, 2010).From this perspective, group identification involves aligning one's interests with the interests of a coalition and acquiring motivations to advance its power and status.
Democratic politics involves complex relations of cooperation and competition between coalitions of multiple kinds, including political parties, factions, social movements, interest groups, ideological communities, and so on.In many democracies, however, there is a tendency for such diverse coalitions to become subsumed into an overarching conflict between a small number of rival political parties, which function as coalitions of coalitions (Federico & Malka, 2021).In the USA, for example, the Republican and Democrat Parties increasingly function as so-called "mega-identities" because of the degree to which party affiliation is predictive of a range of other group allegiances (Mason, 2018), and people intuitively treat parties as socially important alliances that determine patterns of cooperation and conflict between citizens even outside of political contexts (Pietraszewski et al., 2015;Pinsof, et al., 2023).Given this, people who identify with political parties can be understood as aligning their interests with the interests of a coalition that functions to promote shared interests and outcompete rival coalitions.Why might this alignment of interests drive motivated cognition?

Advocacy goals and press secretaries
In society, some professions function to advocate for the interests of specific individuals and institutions (Haidt, 2013;Mercier & Sperber, 2017;Simler & Hanson, 2016;Tetlock, 2002b).For example, the aim of press secretaries and public relations teams is to promote the interests of their clients by interpreting events and framing facts in ways that protect their reputations, justify their decisions, and cast them in a favourable light.Likewise, lawyers are assigned to advocate for specific positionsfor example, the innocence of their client or the guilt of an accused-and their job is to synthesise and present the most persuasive arguments in defence of those conclusions.In such cases, the goal of reasoning and argument is not truth; it is to frame, package, and spin reality in ways conducive to justifying a predetermined conclusion.These professions therefore illustrate two basic lessons: first, that the goal of advocacy is distinct from the disinterested pursuit of truth, a lesson that goes back at least as far as Socrates' arguments with the sophists; and second, that extreme biasspecifically, recruiting evidence and arguments in the service of rationalising predetermined conclusions-sometimes co-exists with a genuine sensitivity to reality.
Lawyers and press secretaries almost never just completely fabricate things.To function effectively as persuasive advocates, they must respond to evidence and engage with arguments (Mercier & Sperber, 2017;Simler & Hanson, 2016;Tetlock, 2002b).
In recent years, a large body of experimental research has demonstrated that advocacy goals automatically and unconsciously bias belief formation in powerful ways (see Butterworth, et al., 2022;Hoffman & Yoeli, 2021).For example, when individuals are incentivised to advocate for conclusions in experimental contexts-including conclusions that they are randomly assigned to argue for and that they have no independent stake in-their beliefs rapidly shift in the direction of such conclusions (Babcock, et al., 1995;Melkinoff & Strohminger, 2020;Schwardmann & van der Weele, 2019;Schwardmann, et al., 2022).Of course, in ordinary life advocacy goals are not randomly assigned in this way.As ultra-social animals for which individual success depends on winning friends and influencing people, individuals are strongly motivated to advocate for their own interests: to portray their motives as prosocial and norm conforming, to persuade others that they have socially desirable traits, and to justify their attitudes and decisions (Mercier & Sperber, 2017;Simler & Hanson, 2016;Tetlock, 2002a).Given this, people are susceptible to strong self-serving biases in what they think and how they reason: they uphold flattering self-images; they take responsibility for good outcomes and externalise responsibility for bad ones; they frame their future prospects in a positive light; they minimise the harms that they inflict and exaggerate the harms inflicted upon them; and they seek to diminish the qualities and achievements of rivals (Alexander, 1987;Bortolotti, 2015;Kurzban, 2011;Mercier and Sperber, 2017;Pinsof, et al., 2023;Taylor and Brown, 1988;von Hippel and Trivers, 2011).3Such self-serving biases reflect automatic and adaptive tendencies to behave as one's own defence lawyer and press secretary (Haidt, 2013;Simler & Hanson, 2016;Williams, 2021b).Given such social goals, however, the tendencies are also constrained by evidence and arguments: just as with real lawyers and press secretaries, self-serving spin doctoring must be constrained by reality to be effective (Haidt, 2001;Kurzban, 2011;Mercier & Sperber, 2017;von Hippel & Trivers, 2011).
This provides the theoretical background for a theory of partisan motivated cognition.Once individuals align their interests with the interests of parties, they will inevitably acquire motivations to advocate for the interests of those parties: that is, to promote their policy platforms and actions and justify their superior claim to power and status over rival parties.As with self-serving biases, coalitional psychology should thus drive party-serving beliefs, transforming individuals into automatic press secretaries for their favoured political coalition.Also as with self-serving biases, however, we should strongly expect such partisan spin doctoring to be highly constrained by evidence and arguments.I will call this the Coalitional Press Secretary Theory of Partisan Cognition (henceforth the Coalitional Press Secretary Theory).

Explanatory virtues of the coalitional press secretary theory of partisan cognition
The Coalitional Press Secretary Theory provides a superior explanation of partisan cognition than purely cognitive theories.First, good explanations cohere with and build on well-established findings and theories elsewhere in science (Lipton, 2003;Newton-Smith, 1981).The theory builds on a significant body of existing scientific research on coalitional psychology, self-serving biases, and the role of advocacy goals in unconsciously biasing cognition.Indeed, once one accepts that motivations to advocate for specific conclusions bias belief formation and that citizens are motivated to promote the power and status of their favoured parties-claims for which there is significant independent evidence-the central ideas of the theory fall out automatically.Moreover, democratic politics provides a context in which motivationally biased cognition is highly likely.Citizens are forming beliefs about phenomena that they have little ability to influence, which means that the personal costs of holding biased beliefs are typically negligible (Kahan, 2017), and such beliefs concern complex, distal phenomena where there is little direct evidence or feedback from reality, which makes it relatively easy to rationalise desired conclusions (Haidt, 2013;Williams, 2022).Thus, even prior to observing specific data concerning how partisan allegiances shape political cognition, we should strongly expect citizens to be motivated to think about politics in ways oriented to promoting and justifying the interests of their favoured parties.
Second, when we turn to relevant empirical data, the Coalitional Press Secretary Theory provides a powerful and parsimonious explanation of a wide range of findings and subtle patterns in those findings.Most fundamentally, the theory does not just predict a correlation between partisan identities and beliefs; it predicts the direction of partisan bias and so the kinds of beliefs likely to be associated with partisanship.These are beliefs conducive to justifying the relevant party's superior claim to power and status over rival parties.This is just what we find: partisans form factual assessments of things like the economy and crime rates that reflect favourably on their party; they inflate their party's successes and rival parties' failures; and they attribute responsibility and blame for good and bad political outcomes in characteristically partisan ways (Achen & Bartels, 2016;Bisgaard, 2019;Frankovic, 2016;Marietta and Barker, 2019;Nyhan, 2020;Thaler, 2022).Such tendencies have been documented in political science at least since Campbell et al. (1960, p.133) observed that party allegiances function as "a perceptual screen through which the individual tends to see what is favorable to his partisan orientation."The Coalitional Press Secretary Theory provides a much deeper explanation of such biased perceptions than standard analyses provided by social identity theory, however (e.g., Mason, 2018).Specifically, if partisan bias is rooted in advocacy goals, partisans will be motivated to believe things that they do not want to be true-indeed, things that they find it aversive or unpleasant to believe-if such beliefs vindicate their party's claim to status and power (Butterworth, et al., 2022;Hoffman & Yoeli, 2021).This prediction is borne out by a significant body of evidence.For example, partisans are often biased towards beliefs that inflate the existence of threats and dangers that their party seeks to address, including the perils posed by rival parties and ideological enemies 1 3 (Finkel, et al., 2020;Frankovic, 2016;Thaler, 2022), and they exaggerate the degree to which they are victimised by such adversaries when doing so supports their party's side of an argument (Pinsof, et al., 2023).
Just as importantly, however, the Coalitional Press Secretary Theory also explains why and in what ways partisan motivated cognition will be constrained.As noted above ( § 5), a significant body of empirical evidence demonstrates that partisans revise their beliefs in response to clear contrary evidence, even when such evidence reflects unfavourably on their party (Bisgaard, 2019;Nyhan, 2021;Tappin, et al., 2023).Some take this as evidence against the strength of partisan motivated cognition (De Vries, et al., 2018;Tappin, et al., 2023).The Coalitional Press Secretary Theory predicts such sensitivity to evidence and arguments, however: for persuasion and reputation management to be successful, they must be responsive to reality. 4evertheless, the theory also predicts that when partisans are forced to acknowledge unfavourable facts, they will creatively interpret and contextualise such facts in ways that rationalise their party's superiority.Once again, this is just what we find.For example, when economic conditions are so bad that citizens converge in acknowledging this, they simply polarise over who to blame for the conditions (Bisgaard, 2015(Bisgaard, , 2019)); when partisans converge in their perception of economic indicators such as the stock market, they polarise over whether such indicators measure the true health of the economy in ways that cast their party in a favourable light (Anson, 2017); and when forced to acknowledge bad actions by their party's leaders, they recall putatively worse actions by rival party leaders in ways that present their own leader as the "lesser of two evils" (Groenendyk, 2013).In an especially striking example of this phenomenon, when a sample of Democrat and Republican voters during the Iraq war converged in their assessment of the number of American casualties and the failure to find weapons of mass destruction, they polarised both in how they interpreted such numbers (i.e., as "high" or "low") and in their explanation of why such weapons were not found in ways that were favourable to their respective parties (Gaines, et al., 2007).Such strategies, whereby partisans acknowledge the same facts but interpret and contextualise such facts in ways that vindicate their party's superiority over rival parties, are ubiquitous (Krishnarajan, 2022;Malka & Adelman, 2022) Now consider a purely non-motivational theory of partisan cognition.According to this theory, the correlations between partisan identities and beliefs reflect factors such as divergent information exposure and disagreements about the trustworthiness of different information sources.Although such factors might explain generic correlations between partisan identities and beliefs, they do not offer any explanation of the direction of partisan bias, or more specifically why such beliefs are biased in just the direction that one would expect given the existence of group-justifying motivations that it is independently plausible to attribute to people.
In response, one might argue that the character of partisan beliefs results not from motivated cognition but from the character of the information that partisans are exposed to.For example, perhaps partisans trust partisan media and party elites and so seek out information from them solely as a means of acquiring accurate information, but such information sources themselves disseminate biased content.Once we turn to a wide range of relevant findings and subtle patterns in those findings, it becomes clear that this theory is far less plausible than the Coalitional Press Secretary Theory.
First, this theory implies that beliefs that promote and justify party interests will generally be mediated by exposure to communicated information, but this is mistaken.When it comes to partisan cognition and group cognition more broadly, there is now a considerable body of evidence demonstrating that people automatically interpret and process information in group-serving ways: they evaluate acts more favourably when they support their ingroup (Claassen & Ensley, 2016;Kopko, et al., 2011); they interpret events in ways favourable to their ingroup (Hastorf & Cantril, 1954;Kahan, et al., 2012;Stanovich & West, 2007); and they selectively learn and recall facts favourable to their ingroup (Frenda, et al., 2013;Jerit & Barabas, 2012;Murphy, et al., 2019) (see Stanovich, 2021).Moreover, people automatically adjust their factual beliefs-for example, their beliefs about the reality and risks of climate change-based solely on whether the relevant facts are framed in ways congenial to their party's policy platform (Campbell & Kay, 2014).
Second, the claim that citizens form biased beliefs because they seek out and trust information sources that are themselves biased raises the question of why individuals would seek out information from or trust manifestly biased sources (Hoffman & Yoeli, 2021).The Coalitional Press Secretary Theory has a simple answer: partisans seek out biased content to acquire intellectual ammunition with which to promote and justify their party's platform and its claim to power and status (Williams, 2022).If citizens are solely motivated by accuracy, however, the decision to seek out and trust information from biased information sources is puzzling.It is puzzling both because the bias in media content is obvious (Benkler, et al., 2018;Iyengar & Hahn, 2009), and because there is a significant body of independent evidence demonstrating that-at least when individuals are motivated to form accurate beliefs-they are highly vigilant and sophisticated when evaluating communicated information (Mercier, 2020).The very fact that partisans appear so credulous in the face of biased and selective content from their side is thus indirect evidence that they are not motivated by accuracy.
Third, purely non-motivational theories fail to explain subtle patterns in the information consumption of partisans.For example, there is evidence that partisans do not just actively seek out information from biased and ideologically congruent media (Robertson, et al., 2023) but even adjust their rate of information consumption in response to the congeniality of news content for their party (Kim & Kim, 2021).Given such patterns, greater media coverage of events often only increases belief accuracy among partisans for whom the events are politically congenial (Jerit & Barabas, 2012). 55 One interesting finding here is that partisans sometimes actively avoid information in tension with partisan beliefs (Frimer, et al., 2017).Although this phenomenon is strongly in tension with purely cognitive explanations of political cognition, it also sits uneasily with the Coalitional Press Secretary Theory.

3
Fourth, purely non-motivational theories of partisan cognition fail to explain why the same kind of belief-forming patterns found in partisan cognition recur across a wide variety of other contexts involving intergroup competition.That is, in contexts as diverse as international conflict, ethnic rivalries, and sports fandom, one sees similar group-serving biases in how individuals interpret the world (Boyer, 2018;Hastorf & Cantril, 1954;Pinker, 2011;Pinsof, et al., 2023).Indeed, this recurrence of similar forms of biased group cognition across a wide range of intergroup contexts is a foundational lesson of social psychology (Tajfel, 1982).The Coalitional Press Secretary Theory explains and unifies this phenomenon: whenever individuals are motivated to promote the interests of a coalition involved in intergroup conflict, they will be motivationally biased towards beliefs conducive to promoting and justifying their side's superior claim to power and status.In contrast, non-motivational theories must assume one of two things: that partisan cognition coincidentally recreates the same patterns of belief caused by group-serving biases in other intergroup contexts, oreven more implausibly-that group cognition never involves motivational biases but somehow gives rise to the same pattern of group-serving beliefs across otherwise extremely diverse cases of intergroup conflict.
In summary, the Coalitional Press Secretary Theory builds on well-established ideas and findings elsewhere in social science, it parsimoniously explains a wide range of relevant evidence, and it has unifying power, treating partisan cognition as one manifestation of more general group-serving biases that arise across all contexts of intergroup conflict.In contrast, even if non-motivational theories can be made consistent with certain coarse-grained descriptions of relevant observations and experimental results, such theories appear ad hoc and implausible once we attend to broader dimensions of theory choice and to diverse findings and subtle patterns in those findings.

Conclusion
Although it conflicts with many people's self-image (Cohen, 2003;Ditto, et al., 2019a), it is a central lesson of political science that party allegiances play a major role in shaping what and how citizens think about politics.Nevertheless, there is persistent disagreement over how to understand this influence.On one view, partisanship comes into frequent conflict with the pursuit of truth and drives powerful forms of motivated irrationality.On another, support for political parties does not bias us away from accuracy; it merely shapes our efforts to form accurate beliefs in complex If political cognition is oriented towards persuasive advocacy, it seems plausible that partisans would be motivated to discover what their rivals and opponents claim so that they can craft counterarguments and responses.One possibility is that this behaviour reflects an alternative form of motivated cognition oriented towards social signalling rather than persuasion (Funkhouser, 2017;Williams, 2021c;see § 8).There are other possibilities as well, however.For example, partisans might be motivated to selectively acquire counter-arguments from preferred ideological sources selected to frame the views of opponents in ways that undermine their credibility (Williams, 2022), or active avoidance of incongruent information might simply be a by-product of the proximate affective responses that normally guide partisan cognition towards the acquisition of effective rationalisations.This is a topic that deserves significantly more research.I am grateful to both Ben Tappin and an anonymous reviewer for raising this important issue.
worlds in which we must be selective about which information to acquire and from whom to acquire it.
In this article I have tried to clarify this disagreement and explain why it has been so difficult to resolve.On one level, this difficulty derives from the fact that the observational and experimental evidence typically advanced in support of the Partisan Bias Hypothesis is consistent with non-motivational theories.On a deeper level, however, it derives from the misguided view that mere consistency with such evidence-mere observational adequacy-should be the aim of theories in this area.Once we turn to richer dimensions of theory choice, consider a better-developed theory, and focus on more fine-grained descriptions of relevant findings, we can see that a version of the Partisan Bias Hypothesis-what I have called the Coalitional Press Secretary Theory-provides a superior explanation of many aspects of partisan cognition than purely cognitive alternatives.
Of course, this sketch of the theory and its explanatory virtues has only been preliminary.Let me conclude by briefly identifying several important areas for future research.
First, I have not identified or explored all of the predictions of the Coalitional Press Secretary Theory.For example, the theory predicts that making party allegiances salient to people should influence how they think (Groenendyk, et al., 2022); that partisans will hypocritically deploy abstract principles and arguments in ways that vary with their persuasive utility (Pinsof, et al., 2023); and that partisan cognition will feature the emotional signature of motivated cognition, in which encountering evidence against motivated beliefs is experienced as threatening and aversive (Westen, et al., 2006).Moreover, I have focused mostly on the individual psychology of partisan motivated cognition, but motivated cognition also has an important social dimension: when groups are motivated to form certain beliefs, the task of rationalising such beliefs is often outsourced to a minority of information producers.The Coalitional Press Secretary Theory thus predicts that much of partisan media should be organised around the production of intellectual ammunition specialised for rationalising party-favourable conclusions (Williams, 2022).Future research should more systematically explore such predictions and evaluate their empirical support.
Second, most research on partisan motivated cognition explores its role in driving misperceptions (i.e., confidently-held false beliefs) and in making people susceptible to partisan misinformation (Nyhan, 2020;Pennycook & Rand, 2019).If the theory developed here is correct, such phenomena are only one possible consequence of partisan motivated cognition.As I have tried to demonstrate, partisan cognition can be extremely biased-that is, motivated by a goal (i.e., partisan advocacy) distinct from truth-even if partisans are responsive to evidence and arguments.The most successful press secretaries can present largely accurate information if they are skilled at combining, framing, and filtering that information in ways that support pre-determined conclusions, and the same lesson generalises to partisan cognition: citizens can function as savvy partisan press secretaries-and so can be highly biased and polarised in their interpretations of reality-even if the number of demonstrably inaccurate beliefs that they hold is small, and even if they are highly responsive to evidence.Given this, political scientists should move beyond the focus on misperceptions and misinformation as the sole consequences of partisan motivated cogni-1 3 tion and explore the many subtler ways in which party allegiances can bias political thought (see Bisgaard, 2019;Gaines, et al., 2007;Malka and Adelman, 2022).
Third, although I have focused on partisan identity, the Coalitional Press Secretary Theory applies in all cases in which individuals are motivated to promote the interests of coalitions, and political parties are not the only important political coalitions.Depending on the context, for example, there are also racial and ethnic groups, nation states, social movements, factions organised around particular leaders, and groups organised around specific policy goals (e.g., Remainers and Leavers in the UK Brexit debate).Moreover, insofar as parties function as coalitions of coalitions, the Coalitional Press Secretary Theory predicts that partisan bias will involve group-serving biases on behalf of the various coalitions that make up each party.In an insightful analysis of the connection between group alliances and political ideology, Pinsof and colleagues (2023) find strong support for this prediction, demonstrating that citizens deploy what they call "propagandistic biases" (i.e., group-serving biases) in defence of the various groups that support their favoured party.
Fourth, the Coalitional Press Secretary Theory identifies one important source of politically motivated cognition, but it is not necessarily the only source.For example, citizens support political parties at least in part because such parties promote their independent values and interests, and such values and interests might constitute an independent source of motivated cognition (D.M. Kahan, et al., 2017).Further, some research explores the ways in which group allegiances drive motivated cognition via motivations to signal group identity and loyalty (Funkhouser, 2022;Williams, 2021a).Although such motivations might interact with the motivation to advocate for party interests described here-affirming beliefs that promote and justify party interests might be especially well-suited to signalling party loyalty, for example-ingroup signalling is a distinct motivation.Future research should therefore systematically explore their connections and the distinctive psychological and social predictions that this alternative theory of partisan motivated cognition generates.
Finally, I have said nothing about individual differences or environmental conditions that might influence partisan motivated cognition.However, it could be that individuals vary in their susceptibility to motivated cognition and that different environmental contexts and affordances influence the strength of motivational biases (Groenendyk & Krupnikov, 2021), and both of these topics deserve further exploration.Further, although I have framed the disagreement as if there are only two positions-partisan cognition either involves motivated cognition or does not-this was solely for expository convenience.In general, human beings are complicated: even if we care about promoting the interests of our ingroup, we also care about accuracy and appearing reasonable, and such goals are likely balanced in subtle ways that vary across individuals and contexts.Future research should therefore move beyond the question of whether partisan motivated cognition exists and more carefully quantify its strength and the various individual and environmental factors that moderate its influence.
the University of Liverpool organised by Robin McKenna (including Robin) for useful and stimulating discussion of the topic.

Declarations
Competing interests The author declares none.
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