Abstract
Belief systems have never surrendered easily to empirical study or quantification. Indeed, they have often served as primary exhibits for the doctrine that what is important to study cannot be measured and that what can be measured is not important to study.
Synthesizing a Science of Ideology
Since the birth of modern civilization, human beings have been creating stories that capture their theories about how the world works and how they should act within this complex world. These narratives both describe and prescribe human action and exist in a kaleidoscope of forms—from religious doctrines to political manifestos and from racial supremacy to authoritarian nationalism. These accounts are broadly termed “ideologies” and envelope humans’ personal and social lives to a considerable degree. The Pew Research Centre estimates that 84.4% of people affiliate with a religious institution, 1 and the International Institute for Democracy and Electoral Assistance approximates that over 1.3 billion people voted in their local parliamentary elections across the world between 2016 and 2019. 2 Exposure to and participation in collective ideologies is therefore remarkably prevalent and consequential to people’s daily lives.
How should ideology be defined? Political theorists, sociologists, and psychologists have espoused (at times radically) different conceptualizations of ideology. Definitions have ranged from the general (e.g., Adorno et al., 1950; Converse, 1964/2006) to the particular (e.g., Platt & Williams, 2002). As a starting point, most contemporary definitions of ideology have recognized that an ideology functions as a force that epistemically organizes beliefs about how society ought to be structured (Adorno et al., 1950; Campbell et al., 1960; Kerlinger, 1984) and how people ought to behave. It provides “both an
This article seeks to make three central claims about the study of ideology with the aim of building a robust science of ideological thinking. First, the term “ideology” has been used in different ways by scholars from the disciplines of politics, sociology, and psychology, and this had led to challenges in distinguishing between psychological and nonpsychological processes in the realm of ideologies. Second, whenever psychologists have investigated the nature of ideological beliefs, they have been largely guided by a theoretical interest in the
In sum, this proposal for an integrated psychology of ideology aims to catalyze interdisciplinary synthesis regarding what it means for ideological scripts to be internalized by the human mind and how the fundamental mechanisms of cognition shape the ideologies that we endorse and evangelize. It also seeks to demonstrate how we can diagnose thought patterns (and individuals, and perhaps communities or societies) that are strongly ideological from those that are weakly so, or not at all. A science that tackles the commonalities between diverse ideologies can facilitate a more conceptually and methodologically mature psychology of ideology.
The History of Demarcating Ideology
Historically, there have been continual changes in the available and predominant ideologies. Correspondingly, there have been shifts in what has been considered an ideology. Perhaps the earliest manifestations of ideologies are evident in folk myths; these narratives theorized about the causal structure of the world, imagining unseen agents that were responsible for objects and occurrences in the observable world (Atran, 2002; Norenzayan, 2013). Myths were elaborated on by organized religions to legitimize and dictate certain forms of personal and social behavior. This was followed (in a historical sequence that is neither linear nor uncontested) by the emergence of “secular religions” in the form of sacralized political action and organization. It was at this point in the development of contemporary political life that the term “ideology” entered common usage, and so ideology is often synonymized with
The term “ideology” was coined during the French Revolution by French “ideologues” who wished “to label a new science outlined in the framework of the Enlightenment programme, the teaching of ideas” (Stråth, 2013, p. 16)—ideology was therefore originally meant to reflect a new science of ideas. Nonetheless, the expression was quickly politicized during Napoleon’s reign and became synonymous with “unrealistic theories that tried to intervene in the spheres of government and political action” (Stråth, 2013, p. 20). By the mid-20th century—after the rise and fall of several totalitarian ideologies—“ideology” was reimbued with a sense of systematicity: Ideologies were conceptualized as long, coherent chains of thought that served as instruments for managing societies and negotiating social and political power. This conceptualization is also mirrored in the exponential rise in the usage of the term “ideology” between 1940 and the 1970s (see Fig. 1). Contemporary definitions of ideology typically deal with the latter political interpretation because this interpretation has emerged most recently on the world stage and rapidly modified social relations and traditional power hierarchies. Since then, much ink has been spilled over whether ideology should be defined in a value-neutral fashion or whether to espouse positive or pejorative definitions. Notably, the use of the word ideology itself has experienced a steep decline since the late 1990s—perhaps as a response to the worry that it is an ambiguous and historically contested term (Corner, 2001; Rorty, 1993).

Frequency of the term “ideology” in English books between 1850 to 2010 according to Google Books Ngram Viewer. The
Some scholars have considered ideology to be a
The Psychological Structure of Ideological Thinking: Domain-General Components
Psychologists have far from neglected ideologies: In fact, rich lines of inquiry in social psychology have sought to unpack the complex processes by which individuals form ideological beliefs. Nonetheless, the study of ideology is marked by substantial balkanization. There is now a psychology of politics (Jost et al., 2003), religion (Norenzayan, 2013), nationalism (Anderson, 1983; Billig, 1995), prejudice (Brandt, 2017; Dovidio et al., 2010; Duckitt & Sibley, 2009b), dehumanization (N. Haslam, 2006), obedience (S. A. Haslam & Reicher, 2007; Reicher & Haslam, 2011), collective action (van Zomeren et al., 2008), moralization (Rhee et al., 2019; Rozin, 1999), conspiracy theories (Douglas et al., 2017; van Prooijen & Van Vugt, 2018), radicalization (Kruglanski et al., 2014), and so on—but there is not an overarching psychology of ideology.
The reasons for this fractionation are historical, methodological, and conceptual and perhaps all can be traced to a theoretical interest in the content of ideological beliefs rather than the structure of ideological thinking. Psychologists have concentrated on the frequency, prevalence, and popularity of specific ideological claims (e.g., political conservatism or supernatural beliefs) rather than why ideological attitudes—regardless of their content—so powerfully captivate the human imagination. An emphasis on the content of ideological beliefs justifies the existing academic landscape, in which each ideological domain merits its own discipline of study. In contrast, a theoretical and empirical focus on the systematic processes of ideological immersion invites a holistic, interdisciplinary outlook that addresses the commonalities across diverse ideologies.
Indeed, a striking—and often understated—observation made by social scientists and theorists is that diverse, and sometimes opposing, ideologies use remarkably similar tools and mechanisms to inculcate their followers and galvanize them toward collective action and self-sacrifice (Hoffer, 1951). In particular, ideologies possess two essential qualities regardless of the content of their beliefs or ambition: They are
First, the doctrinal component of ideologies is facilitated by the existence of a
Second, the relational facet of ideologies—characterized by parochial altruism toward fellow adherents and antagonism toward nonadherents and dissimilar others—is facilitated by processes of
These common tools of ideological indoctrination—rigid dogma and identity markers—can be found consistently across the spectrum of ideological persuasions. 4 From fascism and communism to radical ecoactivism and religious evangelism, ideological groups offer absolute answers to societal troubles, strict rules for behavior, and an in-group mentality through dedicated practices and symbols. These mechanisms are further amplified by propaganda (Holbig, 2013) and systems of punishment for deviance and disbelief (Boyd et al., 2003; Fehr & Gächter, 2002). They are also often augmented via the use of familial and kinship metaphors that depict fellow comrades as “sisters and brothers-in-arms,” religious leaders as “mothers and fathers,” the nation as the “motherland” or “fatherland,” and revolutionaries as the “sons and daughters” of ideological causes (Malešević, 2011, p. 287; Whitehouse & Lanman, 2014). These characteristics emerge even when the ideology is guided by sincere or benevolent intentions and ideals and allow ideologies to endow followers with a sense of coherence, belonging, meaning, and identity that is tightly intertwined with their attachment to the ideological group (Malešević, 2011).
Consequently, an ideology, as defined and evaluated here, possesses two characteristics. First, it has a doctrinal component that is reflected in a doctrine composed of a set of descriptive and prescriptive attitudes about social relations and norms. In other words, an ideology interprets the world and offers prescriptions for how people ought to think, behave, and interact. The doctrine is fixed and resilient in the face of reliable but opposing evidence. Second, because there will be adherents and nonadherents to the doctrine’s prescriptions, an ideology entails a relational component in which there is strong in-group favoritism toward other adherents of the ideology coupled with distrust toward out-groups. 5 These structural components of ideologies can translate into the psychological realm: “Ideological thinking” can therefore be defined as a style of thinking that is rigid in its adherence to a doctrine and resistance to evidence-based belief-updating (i.e., doctrinal) and favorably oriented toward an in-group and antagonistic to out-groups (i.e., selectively relational). 6
This definition posits that individuals vary in the extent to which they display ideological thinking, depending on how epistemically dogmatic and interpersonally intolerant they are toward those who do not belong to their ideological group. It is thus possible to envision a spectrum along which some individuals are ideologically extreme, in which case they are rigidly espousing a doctrine and willing to harm others and incur personal costs (such as self-sacrifice) in the name of the ideology, and others are ideologically moderate and so are receptive to credible evidence and display tolerance for those with whom they disagree. There are therefore gradations from ideological extremism to moderation. Notably, this definition of ideological thinking is agnostic with regard to (a) whether the ideology possesses logical coherence and systematicity, (b) whether it reflects or captures objective truth, (c) whether it has a reality-distortion function, and (d) the extent to which the ideology is purely symbolic or practical. This framework is also agnostic with regard to the ideology’s content—it can be religious, political, or secular. Instead, it emphasizes the structure and style of thinking that ideologies inculcate in followers.
To synthesize a robust and fruitful science of ideology, it is essential to decide on empirically useful definitions of ideological thinking. As outlined above, ideological thinking can be described as a style of thinking that is rigid in its adherence to a doctrine and resistance to evidence-based belief-updating (i.e., doctrinal) and favorably oriented toward an in-group and antagonistic to out-groups (i.e., selectively relational). Ideological thinking is therefore not purely dogmatism or simply intergroup attitudes but a phenomenon that intertwines both. This can be broken down further into tractable subcomponents on the basis of the rich literature on political cognition (see Fig. 2). The doctrinal component involves the embrace of a rigid dogma and consequently the adoption of (a) an absolutist

The components and subcomponents of ideology that are consequently psychologically reflected in ideological thinking.
Using this taxonomy, we can identify ideologies and ideological thinking on the basis of the structure of ideological cognition rather than just the content of the doctrine. This structure-oriented approach does not deny the importance of content, but it can elucidate unexplored research questions. It can therefore expand existing knowledge into a more comprehensive theory of ideology. The four subcomponents (outlined in Fig. 2) are all necessary and jointly sufficient for ideological thinking (and especially ideological extremism) to emerge in the full sense. Rather than purely focusing on whether the ideology deals with questions of political organization, social hierarchies, religious beliefs, environmental protection, or class struggles, the proposed approach implies that we can separate thought patterns that are strongly ideological from those that are weakly so, or not at all. For example, an ideologically extreme individual is one who (a) possesses a rigid, evidence-resistant description of the world, (b) strongly adheres to inflexible prescriptions for how they and others ought to live and act, (c) exhibits intense identification with fellow adherents, and (d) displays active hostility toward nonadherents. In contrast, an ideologically moderate individual is one who (a) adopts a description of the world that is flexible and responsive to evidence, (b) does not rely on or impose on others rigid prescriptive rules for living, (c) displays weak or moderate identification with others who believe in similar worldviews, and (d) does not express hostility or prejudice toward dissimilar others. Consequently, the question of whether the ideologies of these two individuals concern race, gender, class, climate change, religion, or politics is irrelevant as to whether they can be designated as ideologically extreme or moderate.
Can ideological thinking be reduced to mere dogmatism? In other words, can ideologies consist purely of doctrines without relational identities? Such “isms” certainly exist, such as free market capitalism or neoliberalism, but they may not be of genuine psychological interest. Political, historical, or sociological analyses are better suited for ideologies that do not engender in individuals some kind of in-group identification and the potential for out-group derogation. For psychological and cognitive scientists, the ideological phenomena that warrant investigation are those that can breed intergroup intolerance and hostility. Consequently, even ideologies such as veganism or environmentalism can produce ideological thinking for some people because individuals can be both epistemically dogmatic about these ideologies and treat nonadherents with contempt, suspicion, and sometimes violence. Not all individuals who adhere to these ideologies will be dogmatic or intolerant, but some individuals will be—and it is the difference between these two groups that can yield fascinating lines of research for the psychology of ideology.
“Isms” built around openness and tolerance may thus not always fulfill the criteria for provoking ideological thinking. The framework presented here can therefore be used to diagnose ideologies and individuals that are particularly dangerous—when they breed evidence-resistant dogmatism and intergroup intolerance—and those are less toxic. Focusing on the structure of the ideology rather than its content can hence shed light on key processes that were previously obscured because of historical use of the term “ideologies” to refer to a wide variety of phenomena.
Theories of Ideology
To situate this account within broader research on ideologies—and to highlight its novelty and significance—it is valuable to differentiate the phenomenon of ideological thinking outlined here from past or existing theories of ideology and related constructs. Between the 1960s to the 1980s, political scientists largely defined a person who is “ideological” as one who possesses a coherent and stable belief system (Friedman, 2006; Jost, 2006), and so many political scientists debated the extent to which ordinary citizens are
In sociology, ideology has typically been evaluated in relation to systems of power, legitimacy, and collective imagination (Kumar, 2006), especially in the context of capitalism, religion, fascism, and the production of knowledge (Hall, 1977/2018). For individuals to be “ideological” in the sociological sense, they are defined as having simplified, reduced, and distorted a complex social reality; ideology is in an antagonistic tension with truth and science (Vincent, 2010). Other accounts that seek to link the sociological and philosophical critique of ideology with political concerns have posited that “what makes political thinking
Within psychology itself, ideology—the infamously slippery construct—has often been synonymized with “belief system,” “worldview,” “social attitudes,” “values,” “culture,” “life philosophy,” or “political orientation.” It is useful to briefly review how these terms relate to ideology, as conceptualized here. Koltko-Rivera (2004) viewed worldviews as sets of beliefs and assumptions that describe reality. Following a qualitative and historical review, Koltko-Rivera (2004) listed an extensive number of topics for worldview beliefs, such as worldviews on morality, agency, interpersonal justice, authority, humanity, and more. Although valuable and widely appreciated, Koltko-Rivera’s model of worldviews includes over 40 possible worldview topics and so struggles to delineate tractable phenomena that can be of easy use to the psychologist of ideologies. Saucier (2000, 2013) adopted a more empirical approach, relying on a factor analysis of dictionary-derived questionnaire items to evaluate the structure of terms that end in -ism, such as liberalism, nationalism, ethnocentrism, fundamentalism, individualism, spiritualism, and others. This resulted in five dimensions that capture such -isms, which Saucier labeled tradition-oriented religiousness, subjective spirituality, unmitigated self-interest, communal rationalism, and inequality-aversion (Saucier, 2013). These dimensions, especially tradition-oriented religiousness and inequality-aversion, were related to two ideological orientations that constitute Duckitt and Sibley’s (2009a, 2009b, 2010) dual-process motivational (DPM) model: right-wing authoritarianism (RWA) and social-dominance orientation (SDO). The DPM model moves away from unidimensional accounts of ideology that emphasize a single left-right political spectrum (e.g., Adorno et al., 1950; Jost et al., 2003) and instead proposes that RWA and SDO are two distinct ideological dimensions that express separable psychological and motivational processes and traits. According to the DPM account, individuals who score highly on RWA are motivated to establish collective security in response to threats, whereas those who are high in SDO are concerned with establishing group dominance and superiority. The utility of the DPM approach is clear and has been applied to various ideological outcomes such as antigay attitudes (Moor et al., 2019), antivegan attitudes (Judge & Wilson, 2019), immigration attitudes and postcolonial ideology in New Zealand (Satherley & Sibley, 2016, 2018), as well as the evolution of political ideology (Claessens et al., 2020). The authoritarian-aggression element of the DPM evaluates hostility toward individuals perceived to be dissident to endorsed authorities or deviant from embraced social conventions (Mavor et al., 2010), and so this line of research can help productively inform research on the relational components of ideological thinking. Nonetheless, the locus of the intergroup dynamic in the DPM approach is about how individuals view social structures rather than how they treat others who share or deviate from their ideology: There is little attention to how individuals treat adherents vs nonadherents (as in the relational component suggested here) or how dogmatically they adhere to these authoritarian or hierarchical ideologies (as in the doctrinal component). The present framework on ideological thinking therefore fills a gap in existing theories of the components of ideologies but also speaks collaboratively to such accounts.
Another set of theories that focus on the motivational origins of ideologies, and consider ideologies in a fairly general way, are significance-quest theory (SQT; Kruglanski et al., 2014), uncertainty-identity theory (UIT; Hogg, 2014), and terror-management theory (TMT; Greenberg & Arndt, 2011). Each posits that individuals adhere to ideologies to satisfy needs to achieve meaning (SQT), certainty (UIT), and a sense of endurance and esteem in the face of mortality (TMT). The current framework can be compatible with—and help expand—these theories by providing greater specificity about the nature of ideological thinking and by identifying structural cognitive features of ideologies—and not only the motivations they satisfy—that make some brains more susceptible to ideological thinking than others. What aspects of achieving meaning or certainty push individuals toward epistemic dogmatism? And which contribute toward interpersonal intolerance? An integrated account of ideological thinking will support a more mechanistic approach to these motivational theories.
If we examine research on racism, nationalism, sexism, religion, and other ideologies, we can detect how doctrinal and relational components are evident repeatedly within these diverse ideologies. In the context of racism, Jones (2000) defined personally mediated racism as consisting of adherence to racist beliefs and assumptions about the links between race, biology, and ability as well as differential treatment of others in accordance with this racist ideology (Trawalter et al., 2020). The doctrinal and relational components thus reappear in the context of racist ideologies. Likewise, prominent theorists of nationalism (T. Blank & Schmidt, 2003; Feshbach, 1994; Kosterman & Feshbach, 1989) defined it in terms of a doctrine of national superiority, dominance, and militarism combined with positive in-group regard and hostile out-group treatment, implicitly echoing the doctrinal and relational features. Further, research on gender ideologies highlight how it encompasses a nonegalitarian ideology that assumes binary gender roles based on essential biological differences (i.e., the doctrine) and malicious treatment of individuals who deviate from the expectations of this doctrine (Glick & Fiske, 2001; Hammond and Overall, 2013; Saguy et al., 2021). Likewise, in a comprehensive account of the cognitive dynamics of religion (Barrett, 2007), Whitehouse (2000, 2004) proposed that religiosity can cluster into two distinct modes: “doctrinal” and “imagistic.” In the doctrinal mode, religion focuses on transmitting and retaining highly complex bodies of knowledge (e.g., through theological texts and teaching). In the imagistic mode, religion takes the form of highly emotionally arousing events and rituals that provoke feelings of interpersonal connection and oneness. These modes, empirically corroborated through anthropological research (Whitehouse, 2002; Whitehouse & Martin, 2004), map on nicely to the psychological framework presented here, which emphasizes ideologies’ doctrinal components on one hand and relational features on the other. Thus, even a cursory view of a range of ideologies reveals that both doctrinal and relational features characterize the psychological structure of ideologies, reappearing in multiple guises that can be analyzed in a content-free fashion.
Psychology of Ideology
Psychological differences according to ideological content
As noted earlier, psychological research on ideologies has largely focused on the discrepant content of ideologies rather than the commonalities in the cognitive style these can impose on followers. As a result, the most popular experimental design has examined individuals who identify with the mission of a particular ideology and compared them with those who self-identify with the opposing ideology. In political psychology, this has taken the form of methodological comparisons between self-identified political conservatives and liberals. In other social-psychology subfields, this approach is featured in the comparison between religious and atheist individuals or between racist and nonracist individuals.
Content-based comparisons have yielded a profound theoretical and empirical debate between researchers who identify psychological differences between right-wing and left-wing individuals (e.g., Baron & Jost, 2019; Jost, 2017; Jost et al., 2003; Hibbing et al., 2014; Nilsson & Jost, 2020) and researchers who challenge the widely held assumption that such differences exist (e.g., Bakker et al., 2020; Brandt et al., 2014; Crawford, 2017; Crawford & Brandt, 2019, 2020; Crawford & Pilanski, 2014; Ditto et al., 2019; Frimer et al., 2017; Greenberg & Jonas, 2003). The findings from the political-psychology literature have illustrated that direct comparisons of right-wing versus left-wing participants do generally reveal psychological differences in personality, motivations, values, and cognition. For instance, research on the personality and motivations of political conservatives and liberals in the United States has shown that conservatives tend to self-report a greater need for closure, structure, order, certainty, and absence of ambiguity (meta-analysis by Jost et al., 2018; see also Carney et al., 2008; Gerber et al., 2010; Jost, 2017; Jost et al., 2009). Political liberals, on the other hand, report a more favorable attitude toward science (J. M. Blank & Shaw, 2015; Lewandowsky & Oberauer, 2016; Tullett et al., 2016; but see also Washburn & Skitka, 2018) and tend to perform better on tests of cognitive ability (Choma & Hanoch, 2017; Deary et al., 2008; Eidelman et al., 2012; Heaven et al., 2011; Hodson & Busseri, 2012; Onraet et al., 2015; Yilmaz & Saribay, 2017). Political liberals are also more resistant to conspiracies or misinformation (Jost et al., 2018; Miller et al., 2016; Pennycook & Rand, 2020; Pfattheicher & Schindler, 2016; Sterling et al., 2016). Further research into values and moral foundations has suggested that political conservatives adopt more “binding” values such as sanctity, authority, and loyalty, whereas political liberals value more “individualizing” forms of morality that emphasize fairness and care (Graham et al., 2009, 2011; Kim et al., 2012; Nilsson & Erlandsson, 2015; Van Leeuwen & Park, 2009; however, for evidence that ideology drives moral intuitions, see Hatemi et al., 2019). The emerging field of political neuroscience (Haas et al., 2020; Jost et al., 2014; Nam, 2020; Smith & Warren, 2020; Zmigrod & Tsakiris, 2021) has even revealed differences between political liberals and conservatives in their neurobiology (e.g., Amodio et al., 2007; Haas et al., 2017; Kanai et al., 2011; Nam et al., 2018; Oxley et al., 2008; Schreiber et al., 2013) and in their neural responses to affective (Carraro et al., 2011; Smith et al., 2011), facial (Vigil, 2010), and political (Leong et al., 2020) content. Although this is far from an exhaustive review, most outlooks on the literature will conclude that when politically opposed groups are compared on the basis of self-categorizations of ideological affiliations, psychological differences between them do emerge.
Psychological commonalities in ideological thinking
At the same time, however, when studies have taken an approach that emphasizes ideological extremity rather than purely focusing on the mission of the ideology, a more complex picture has surfaced. From a methodological standpoint, these studies often use measurement tools that tap into continuous individual differences in ideological attachment, extremity, and partisan radicality. These investigations have concentrated on the structure of ideological adherence and have illustrated that it is fruitful to study ideological thinking in a way that is largely agnostic as to the aims of the ideology (Zmigrod et al., 2021)—this reveals remarkable psychological commonalities in ideological thinking across a variety of ideological domains.
There have been two lines of research within psychology that have revealed the striking similarities in the psychological underpinnings of ideological thinking across disparate ideological domains. The first line of research has centered on personality and motivational factors (measured via subjective self-report questionnaires), and the second has focused on the implicit cognitive factors (measured with objective neuropsychological and behavioral tasks) underlying ideological thinking.
Personality traits and motivations
In terms of personality and motivation, it is possible to synthesize common dispositions that predict ideological thinking across domains. Personality traits associated with reduced open-minded thinking (Pennycook et al., 2019), heightened sensitivity to distress and fear (for reviews, see van Prooijen et al., 2015; van Prooijen & Krouwel, 2019), avoidance of social risk-taking (Zmigrod et al., 2021), and intolerance of uncertainty (for review, see Hogg, 2014) have been generally implicated in ideological thinking in the context of various ideological identities and groups. Another example centers on the theory that intergroup behavior that avoids foreign, dissimilar others may be rooted in behavioral adaptations that protect against infection (the so-called behavioral immune system). Processes associated with disgust sensitivity and pathogen avoidance have been implicated in authoritarian worldviews, out-group derogation, and moral judgments across multiple psychological paradigms and cross-cultural ecological studies, and across multiple ideological domains (e.g., Ji et al., 2019; Karinen et al., 2019; Tracy et al., 2019; Tybur et al., 2016, 2018; Zmigrod, Ebert, et al., 2020). Recent research centered on dogmatism—measured through individuals’ general receptivity to evidence and respect for credible alternative viewpoints—has shown that dogmatic individuals have highly impulsive personalities (Zmigrod et al., 2021). Impulsivity was also implicated in individuals endorsing ideological violence to protect their in-group (Zmigrod & Goldenberg, 2021), suggesting impulsivity contributes to ideological tendencies (Zmigrod et al., 2021). In addition, from a motivational perspective, work on the psychology of political action has posited that motivations surrounding identity, efficacy, emotion, and morality may be core motivations for ideological action across a diversity of ideological contexts (Cichocka et al., 2018; Osborne et al., 2019; Pliskin et al., 2020; Van Bavel & Pereira, 2018; van Zomeren, 2016).
It is noteworthy that an immense array of personality traits have been studied in relation to one ideological domain (e.g., political conservatism) but not rigorously examined in others, making extrapolation of the psychological correlates of “ideological thinking” challenging. For instance, the role of intuitive versus analytic thinking has been examined in the context of political conservatism and religiosity (for a meta-analysis, see Pennycook et al., 2016), but its role in relation to dogmatism and ideological extremity has not been carefully addressed. Likewise, the cognitive science of religion has discussed the role of mentalizing abilities in predicting religious and paranormal beliefs (e.g., Gervais, 2013; Jack et al., 2016; Norenzayan et al., 2012; Van Elk & Aleman, 2017), but this has not been coherently linked to the mind-perception literature in intergroup psychology (e.g., Fiske & Neuberg, 1990; Hackel et al., 2014). Conducting research that assesses multiple ideologies simultaneously will help structure future research on the personality antecedents of ideological orientations in a more fruitful direction, allowing delineation of what psychological processes are specific to particular ideologies and which can be evident in adherence to any powerful ideology.
Cognitive dispositions
With respect to the cognitively oriented research, a number of cognitive traits have been recently shown to confer susceptibility to ideological thinking (Zmigrod, 2020). Three notable examples are cognitive inflexibility, impaired strategic information processing, and slower perceptual evidence processing. First, an emerging line of research suggests that a tendency toward cognitive rigidity can foster ideological rigidity. Cognitive inflexibility is operationalized in the neuropsychological literature as a difficulty with switching between modes of thinking and adapting to changing environmental contingencies (Zmigrod, 2020). Mental inflexibility has been implicated in extreme ideological identities (for review, see Zmigrod, 2020) in the context of politics (Zmigrod, Rentfrow, & Robbins, 2020), nationalism (Zmigrod et al., 2018), religion (Zmigrod, Rentfrow, Zmigrod, & Robbins, 2019), dogmatism (Zmigrod, Zmigrod, et al., 2019), and a willingness to endorse violence and self-sacrifice (Zmigrod, Rentfrow, & Robbins, 2019). Importantly, cognitive rigidity was manifest on both the extreme right and the extreme left (Zmigrod, Rentfrow, & Robbins, 2020), suggesting that ideological extremity may be as psychologically important as the mission of the ideology. These studies quantified cognitive inflexibility with objective behavioral tests of executive function and perception, in which participants were asked to continuously change between mental rules and categories. Consequently, findings using behavioral experimental paradigms are not susceptible to biases of social-desirability, self-perception, and social norms that can become manifest in self-report questionnaires. This line of research illustrates that individual differences in cognitive inflexibility can confer susceptibility to ideological thinking (Zmigrod, 2020).
Furthermore, recent research examining the cognitive profiles of a range of ideological attitudes found that impairments in strategic information processing were linked to more conservative, authoritarian, nationalistic, and religious tendencies (Zmigrod et al., 2021). 7 This impairment was also evidenced in individuals who were more willing to support extreme progroup actions to protect their in-group. These impairments were manifest in performance on executive-functioning tasks associated with working memory and planning, illustrating that there are common cognitive roots to ideological thinking across a range of ideological contexts. A difficulty in planning and executing complex action sequences in basic perception may thus increase people’s reliance on coherent collective dogmas that simplify the world into absolute explanations and clear behavioral prescriptions.
The study of low-level perception and cognition has further revealed that how the mind processes perceptual evidence can confer susceptibility to ideological dogmatism across a diversity of ideologies. Using drift-diffusion modeling of trial-by-trial performance on two forced-choice tasks illustrated that slower evidence accumulation of perceptual data is linked to a dogmatic thinking style (Zmigrod et al., 2021). This suggests that nondogmatic individuals are better able to process and accumulate evidence in perceptual decision-making contexts
Finally, the analysis of perceptual decision-making processes demonstrated that response caution—a perceptual preference for accuracy over speed in tasks in which both accuracy and speed are rewarded—was related to more socially conservative and nationalistic worldviews (Zmigrod et al., 2021). Cautious perceptual strategies may therefore translate into cautious (i.e., conservative) ideological beliefs. Studying the relationship between ideological attitudes and individual differences in low-level perceptual and cognitive processing can therefore help elucidate the underpinnings of ideological thinking.
Conceptual and Methodological Directions
An emergent conclusion from the observed similarities of diverse ideologies is that we should study ideological thinking and related processes under one umbrella. An appreciation of the psychological structure of ideological thinking can be empirically productive and theoretically valuable. How can this be achieved? Let us examine the directions which this emerging field can take in terms of (a) conceptual and (b) methodological future avenues.
Developing a conceptual research agenda
Building on this integrative framework, a clear guiding research agenda for this burgeoning field can be constructed. In particular, one can envision three major research questions that need to be addressed:
Focusing and delineating research efforts along these lines will allow us to address the nuanced processes that confer initial susceptibility to internalizing ideological doctrines, as well as the mechanisms that reinforce or dampen these effects. It will enable the field to construct comprehensive, causally minded theories and paradigms that can be positioned on par with other major scientific endeavors. When we adopt a framework that seriously engages with the psychological phenomena that underpin political thought and action, we can formulate socially pertinent questions that address the bidirectional links between ideologies and cognition.
To advance an integrated psychology of ideology that taps at these questions, it is essential to collaboratively examine the psychology of religion, political psychology, moral psychology, intergroup psychology, and the study of obedience, conformity, and prejudice. This will allow us to evaluate psychological processes that have been hypothesized to be ideology-specific and to interrogate whether these are truly ideology-specific or have simply not been studied (sufficiently) in the context of other ideologies. We can then ask the essential questions, that is, why some psychological traits are predictive of adherence to certain ideologies and not others and why some psychological dispositions are predictive of extremity regardless of the ideology’s content. It is only through a rigorous integrative theoretical approach that we can design empirical tests that can truly begin to tap at mechanistic explanations in the psychology of ideology. Furthermore, it will allow researchers to build theories that directly address the research questions about the origins, processes, and consequences of engagement with ideological doctrines. We can thereby achieve greater precision in our mechanistic accounts of the ideological mind—arriving at general principles as well as nuanced trajectories that consider where, when, and why the doctrine of the ideology can shape its impact on the minds of adherents.
A multitude of excellent examples in recent research have begun separating the content and structure of ideologies, and thereby elucidated the psychological antecedents, processes, and consequences of ideological engagement. With regard to questions of the cognitive antecedents of ideology, Peterson and Iyengar (2021) found that both political liberals and political conservatives exhibit sincere motivated reasoning of misinformation, and both are influenced by moderate insincere cheerleading effects that shape their information processing of political facts. By putting into competition alternative theories of partisan information-seeking behavior, including content-oriented and structure-based hypotheses, the authors fruitfully clarified the nature of ideological gaps in news evaluation. Another example mentioned earlier is the data-driven investigation by Zmigrod and colleagues (2021) that examined the psychological factors that predict ideological thinking in a range of ideologies. This study revealed that there are certain cognitive and personality dispositions that predict strong or dogmatic adherence to
In relation to questions on the psychological processes of ideological cognition, recent research on ideological social action in online social networks has been able to control for both the content and extremity of messages and study these interactive effects. This approach has revealed that moral emotions such as anger and disgust proliferate on Twitter for politicians on both the left and right of the political spectrum, whereas certain forms of moral-emotional language and expression were more impactful for conservative political elites than for liberal elites, even after controlling for ideological extremity (Brady et al., 2019). Likewise, when examining politically engaged Twitter users, Boutyline and Willer (2017) found that individuals who were both more conservative and more extreme were more likely to seek out political homophily (affirmations of their views rather than challenges to it). Consequently, by empirically separating content and extremity, it is possible to identify their interacting and amplifying effects on behavior—and consider the (online) ecology that makes these ideological behaviors possible.
Last, with regards to research on the consequences of ideologies on neural and cognitive functioning, Krosch and Amodio (2019) showed that framing resources in terms of scarcity disrupts the neural processing of minority group faces in the context of race. Moreover, this scarcity-induced disruption to neural encoding predicted discriminatory resource allocation of White participants. This finding reveals that the way in which the brain responds to scarcity in its visual encoding of minorities can shed light on the origins of discriminatory and prejudiced behavior in times of economic stress. Hence, context matters when minds process in-groups and out-groups (also shown by Jasko et al., 2019), and so we must develop theories that integrate contextual moderators of brain processes—such as resource levels, conflict dynamics, and stressors—when considering the psychological consequences of ideological narratives. Furthermore, Goudarzi et al. (2019) indicated that economic-system justification is related to muted emotional and physiological responses to manifestations of poverty and wealth. Ideologies can thereby serve psychophysical functions, shaping the nervous system’s responses to a variety of social stimuli. However, scientists of ideological thinking will need to tackle difficult questions about why we observe correspondences between social attitudes and cognitive structure and what behavioral and neural mechanisms underpin these correspondences. This endeavor will involve the use of experimental paradigms, behavioral genetics, and longitudinal and developmental studies to inform a nuanced account of how neurocognitive susceptibilities are co-opted by ideologically prone contexts (Zmigrod, 2021).
Importantly, aiming at theoretical synthesis between ideological content and structure, and between the psychology of diverse ideological narratives, does not mean achieving absolute synchrony in how we study political, religious, and social ideologies. Rather, it propels us to develop broad paradigms that facilitate scientific coherence when we consider ideologies in tandem. Theoretical unification should not necessarily force us to draw false equivalences between ideologies (Baron & Jost, 2019), such as between those that are used for social domination versus those promoted in the name of social equality. The key with this integrative structure-oriented approach is to empirically and theoretically test where diverse ideological movements exhibit parallels and where they differ—and through this endeavor understand who is most attracted to (certain) ideologies and why.
Methodological directions
A key step necessary to advance a theoretically mature (and conceptually adventurous) psychology of ideology is to build appropriate, and sometimes novel, assessment tools. There are three main avenues for future methodologically oriented research that will have a particularly fruitful impact on future studies. First, it is necessary to create content-free measures of ideological attitudes and behavior—tools that assesses ideological thinking without invoking the particular content of that ideology. Measures for which the content is easily substitutable with simple alterations are also valuable, such that the structure of the questions is consistent regardless of the ideology in question. This is important to be able to truly compare the psychological correlates of diverse ideological orientations. This will also allow for research outside of WEIRD (White, educated, industrialized, rich, and democratic) samples, which is especially critical to augment the cross-cultural and historical validity (Henrich et al., 2010; Muthukrishna et al., 2020; Roberts et al., 2020)—and highlight instances of cultural specificity—of this emerging science.
Second, there is a need for measures that tap at the structure of ideological thinking by separately quantifying the doctrinal and relational components of ideologies (see Fig. 3). For instance, measuring individuals’ embrace of a dogma would involve surveying their beliefs about the causes of societal conditions (tapping into the description subcomponent of the doctrine) and assessing their levels of endorsement of the dogma’s prescriptions and the need to punish when there is deviance from the ideology’s rules (prescription subcomponent). To evaluate the relational component, it may be necessary to measure individuals’ identification and personal-identity fusion with the ideological group and the extent to which they would be ready to self-sacrifice for its causes (group-identification subcomponent). Measuring out-group derogation would involve surveying individuals’ discriminatory behavioral tendencies and their endorsement of violence against nonadherents (prejudice and hostility subcomponent). There are measures that assess how one would treat nonadherents, or one’s levels of prejudice, but these measures are usually not incorporated into the same study design as those that assess how evidence-resistant an individual is with regard to that ideology. This precision in the assessment of the structure of ideological thinking would facilitate research of pertinent questions, such as: How do the doctrinal and relational aspects of ideological thinking emerge in tandem within an individual? How are the doctrinal and relational elements structurally related? That is, does one temporally precede the other and how do they reinforce and amplify each other? What personal and social experiences or motivations affect the emergence of each? Do the doctrinal and relational components possess separable or similar cognitive correlates? What are the real-world manifestations of the relational component without a doctrinal component (e.g., avid sports fans 8 ) or the reverse (e.g., lone suicide terrorists 9 )? Unpacking the structure of ideological thinking through appropriate methodological tools is therefore a key next step for this line of research.

Methodological directions for a unified psychology of ideology.
Last, the field needs assessment tools that address the temporal dimension of ideological engagement in order to study the whole process of ideological immersion, from exposure to adherence to extremism. Each stage between initial exposure to radical adherence and self-sacrifice is likely to have overlapping as well as unique susceptibility factors, and so we need appropriate assessment tools to evaluate individuals’ position at each stage. Indeed, developmental and longitudinal studies will be necessary to elucidate causal links and self-reinforcing loops between cognitive dispositions and ideological identity and behavior.
Early seeds of these approaches can already be seen in recent research and can be built on in order for the field to attain greater methodological maturity (Rollwage et al., 2019; Zmigrod & Tsakiris, 2021). For example, a measurement tool that has grown in popularity is the identity-fusion index (Jimenez et al., 2016), in which the participant is asked to move a small circle labeled “Me” in relation to a large static circle labeled with the name of the ideological group (e.g., a personally relevant religious group, political party, or nation). The amount of overlap between the two circles and the distance between the circles can be used as a metric of personal feelings of immersion with the ideological group. The power of this measure lies in its applicability to any ideological or social group, such that the amount of identity fusion is quantifiable and translatable between ideologies. The identity-fusion index has been used in the context of nationalism (Bortolini et al., 2018; Jong et al., 2015; Kapitány et al., 2019; Zmigrod et al., 2018), political partisanship (Misch et al., 2018; Zmigrod, Rentfrow, & Robbins, 2019), resilience in the face of terror (Jong et al., 2015), and willingness to engage in extreme protest and progroup behavior (Kunst et al., 2018; Paredes et al., 2019; Purzycki & Lang, 2019). The identity-fusion index therefore satisfies the criterion of being easily content-substitutable (by altering the group label on the large circle) and by tapping into the group identification subcomponent of ideological thinking. It can also be used in longitudinal designs (e.g., Misch et al., 2018) because it involves continuous scales that capture a large range of variation in responses and can be repeated with little interference from memory of past responding.
Another attempt to create a content-free or content-substitutable measure is the Open-Minded Cognition Scale, in which the scale items can be easily adjusted to target general, political, or religious open-minded cognition (Price et al., 2015). For instance, the six-item scale contains items such as “I am open to considering other (political/religious) viewpoints” and “I have no patience for (political/religious) arguments I disagree with.” Nonetheless, Crawford and Brandt (2018) challenged the predictive validity of the Open-Minded Cognition Scale and suggested that it may be best conceptualized as a measurement of
Conclusions
As the political thinker Walter Lippmann noted in 1922, the political environment in which humans are situated is altogether too big, too complex, and too fleeting for direct acquaintance. We are not equipped to deal with so much subtlety, so much variety, so many permutations and combinations. And although we have to act in that environment, we have to reconstruct it on a simpler model before we can manage it. (Lippmann, 1922/1949, p. 11)
Ideologies thereby “impose a certain character on the data of our senses before the data reach our intelligence” (Lippmann, 1922/1949, p. 65)—and it is this profound mental structuring and filtering effect that renders ideological thinking an important object for rigorous investigation.
Given the kaleidoscopic diversity of mass movements, doctrines, and regimes that characterize human history and culture, it is urgent and paramount to isolate and define the core processes of ideological adherence, immersion, and extremism. A synthesis of the multitude of literatures that deal with this topic indicates that there are core commonalities in the substrates of adherence to ideological doctrines regardless of their content. But there are also likely to be important differences that are ideology-specific. A holistic and integrated psychology of ideology will be able to catch these nuances and offer pegs on which to hang and identify the various psychological dispositions and processes that propel individuals to process and respond to the world in an ideological fashion. Consequently, it is valuable to cluster these behaviors and tendencies in common terms and under unified theoretical frameworks if scientific endeavors to deconstruct these phenomena are to be meaningful and applicable. An integrated psychology of ideology will allow us to more fully comprehend the susceptibility factors—and antidotes—to worldviews that are dogmatic, extreme, and hostile to dissimilar others.
This article set out to synthesize a tractable framework through which we can comprehend ideological thinking and to demonstrate that we need to address the unfruitful balkanization of this field. A siloed field is the result of an interest in the content of ideological beliefs, such as why people believe in omnipotent supernatural forces or why they adhere to hierarchical conceptualizations of social relations. A unified field would allow us to evaluate questions about the structure of ideological thinking and thereby also to isolate the role of an ideology’s content. Both levels of analysis—the structural and the substantive—can be brought to the fore, but only if we recognize and learn to quantify them effectively. To move the field forward, we must disambiguate these two levels and find ways to bring them into contact. Future studies need to carefully consider and delineate which level of analysis they are examining or neglecting. This will divulge fascinating and pertinent questions, such as why we observe repeated patterns of ideological indoctrination across cultures and throughout history and why some people are susceptible to dogmatic thinking regardless of their political leanings. How are ideologies “inherited” and communicated? How malleable are the ideologies people hold? What ideologies have the most powerful cognitive impact? Through research practices that seriously consider the multitude of ideologies that have graced (and harmed) human existence, researchers will be able to examine holistically what happens to our behavior and brains when we are inculcated with ideological mindsets. It is imperative to view ideologies (and the historical “-isms” that have been made automatically equivalent to ideologies) in a critical, creative, and reflexively nondogmatic fashion.
Hence, it may be time to reevaluate Converse’s observation (quoted in the epigraph) that belief systems do not concede easily to empirical assessment. Since Converse published
