Abstract
Keywords
Political polarization is a pressing social problem in the United States. Polling data from the American National Election Studies suggest that the degree to which liberals and conservatives dislike each other is at an all-time high (Iyengar et al., 2019). Moreover, animosity between political groups is growing faster in the United States than it is in other Western democratic nations (Boxell et al., 2023). In fact, liberals and conservatives have become so divided in the United States that social scientists have started to describe this division as sectarian—that is, as so extreme that it is psychologically akin to a religious division (Finkel et al., 2020). Indeed, research suggests that liberals and conservatives have such strong faith in the moral superiority of their own political groups that they have come to view political outgroup members as alien (Ahler & Sood, 2018), as untrustworthy (Druckman et al., 2022), and in many cases, as sub-human (Cassese, 2021; Martherus et al., 2021; Pacilli et al., 2016).
The tendency to regard political outgroup members as sub-human—referred to throughout this article as
Of course, being able to circumvent political (meta-)dehumanization requires understanding political (meta-)dehumanization. The focus of the present article, therefore, is on adding to scientific understanding of these phenomena, focusing on two general research questions. First, do liberals and conservatives differ in the types of dehumanization that they cognitively emphasize when mentally representing one another? Second, are liberals and conservatives sensitive to
The reason for focusing on the former question—of whether liberals and conservatives differ in the types of dehumanization that they cognitively emphasize—is that distinct types of dehumanization are implicated in distinct behavioral responses (e.g., different ways of expressing intergroup animosity; Andrighetto et al., 2014; Haslam & Loughnan, 2014; Kteily & Landry, 2022). For example, one distinction in dehumanization research contrasts “animalistic” with “mechanistic” dehumanization. Whereas animalistic dehumanization is often associated with aggressive responses, mechanistic dehumanization is more likely to be associated with treating a target as inert or as a means to an end (Haslam & Loughnan, 2014). Relatedly, distinct types of dehumanization may necessitate different types of psychological interventions—a target likened to an animal might benefit more from an intervention that emphasizes their intellect whereas a target likened to a machine might benefit more from one that emphasizes their capacity for emotion. This same logic extends beyond the distinction between animalistic and mechanistic dehumanization to any context in which targets might be dehumanized in distinct ways. If researchers wish to identify the downstream consequences of political dehumanization, and to perhaps curb it altogether, they stand to benefit from understanding if and how dehumanization differs between liberals and conservatives.
The reason for focusing on the latter question—of whether liberals and conservatives are sensitive to how they are dehumanized—is to gain purchase on information that might be useful for correcting inaccurate meta-perceptions. Generally, the research literature on political meta-dehumanization suggests that liberals and conservatives overestimate how dehumanized they are in the minds of political outgroup members (Landry et al., 2021; Moore-Berg et al., 2020). However, it may be the case that liberals and conservatives overestimate certain types of dehumanization, but not others. Knowing which elements of partisans’ meta-perceptions are most inaccurate can help researchers to tailor interventions aimed at increasing meta-perceptual accuracy—which has itself been implicated in reducing animosity between political groups (Lees & Cikara, 2020).
Types of Dehumanization in the Minds of Liberals Versus Conservatives
Social scientists have tended to measure political dehumanization as a unitary construct. Although the measure of choice varies from study to study—at times capturing animalistic dehumanization (e.g., Pacilli et al., 2016), for example, and at other times capturing perceived “evolved-ness” of partisans (e.g., Landry et al., 2021; Moore-Berg et al., 2020)—participants are typically asked to reflect on their global impression that partisans are human or inhuman, but are not required to specify which particular attributes make those partisans human or inhuman. The use of unitary measures in the context of political dehumanization may limit our understanding of the phenomenon. For one, there are in principle several distinct
The present article expands on this possibility by suggesting that liberals and conservatives may cognitively emphasize the dimensions of
The present research examines whether these two types of dehumanization, termed
Reverse Correlation as a Means of Capturing Political (Meta-)Dehumanization
Recent research suggests that reverse correlation can be a viable tool for measuring dehumanization in an unobtrusive, relatively implicit manner (e.g., Kunst et al., 2018). Reverse correlation is a technique in which researchers ask participants to view hundreds of pairs of faces, and in which researchers ask participants to select the face in each pair that most closely approximates their representation of a particular target group (e.g., their representation of what a
In addition, this past work suggests that mental representations (as indexed by reverse correlation) can pick up on dehumanization into which participants have little or no awareness (Petsko et al., 2021). The benefit of relying on reverse correlation, then, is that it can measure what is in the minds of liberals and conservatives in ways that might not be capturable from self-report measures alone. This feature of reverse correlation is desirable, as the great majority of what scientists know about political dehumanization has come from studies that rely exclusively on self-report measures (e.g., Cassese, 2021; Martherus et al., 2021; Moore-Berg et al., 2020). In the present work, we examine whether reverse correlation can be used to (a) detect different types of dehumanization that might exist in the minds of liberals versus conservatives, respectively, and if so, whether it can be used to (b) weigh in on the question of whether liberals and conservatives are sensitive to how they are dehumanized by political outgroup members. Notably, the use of reverse correlation to assess sensitivity to how one is dehumanized—to assess what we later refer to as
The Present Studies
We conducted two reverse-correlation studies (
Study 1
Study 1 was designed to examine whether liberals and conservatives differ in the types of dehumanization that they cognitively emphasize when mentally representing one another. In particular, Study 1 examined whether liberals’ mental representations of conservatives more strongly emphasize
Method
Study 1 occurred in two phases. In Phase 1, participants (half of whom were politically conservative and half of whom were politically liberal) called to mind their mental representations of either
Participants
Recruitment for Phases 1 and 2 was conducted via CloudResearch.com (Litman et al., 2017). Participants were adults living in the United States with a track record of high-quality survey responding (according to CloudResearch’s Approved Participant List). In addition, half of the participants in Phase 1 were required to have a track record of identifying either as “conservative” or as “very conservative,” whereas the other half of participants in Phase 1 were required to have a track record of identifying either as “liberal” or as “very liberal.” Demographics for all final participants from Phases 1 and 2 can be found in Table 1.
Final Participant Demographics (After Exclusions) From Study 1.
Phase 1 had an a priori goal of obtaining
Procedure
Phase 1
Participants in Phase 1 completed a standard reverse-correlation procedure that was designed to approximate how they mentally represented political ingroup members versus political outgroup members. In particular, participants viewed 300 pairs of blurry faces, and their task was to choose the face in each pair that looked more like a conservative or that looked more like a liberal (by random assignment). The face pairs themselves were presented in a randomized order for each participant, and were generated by imbuing a black-and-white base image with random visual noise (Dotsch, 2016; Dotsch & Todorov, 2012; see Figure 1). In every pair of faces, one image was created by adding random visual noise to a base image, and the other was created by adding the inverse of that noise to the same base image (see Figure 1). The base image that was used was an averaged, neutrally expressive male face (taken from the AKDEF database; see Lundqvist & Litton, 1998). The use of this particular base image is common in research that uses the reverse-correlation paradigm (e.g., Dotsch & Todorov, 2012).

Base Image on Which Reverse Correlation Task Trials Were Based.
After the task was over, the research team computed composite images of the faces that participants chose in each condition, broken down by whether the participants themselves were liberal versus conservative. To create the composite image of how conservatives mentally represent ingroup members, we created a morphed average of all the faces conservative participants chose while thinking of “a conservative.” To create the composite image of how conservatives mentally represent outgroup members, we created a morphed average of all the faces conservative participants chose while thinking of “a liberal” (see Figure 2, left-hand column). Likewise, to create the composite image of how liberals mentally represent ingroup members, we created a morphed average of all the faces liberal participants chose while thinking of “a liberal.” To create the composite image of how liberals mentally represent outgroup members, we created a morphed average of all the faces liberal participants chose while thinking of “a conservative” (see Figure 2, right-hand column).

Composite Images of Political Ingroup and Outgroup Members (Study 1).
Phase 2
In Phase 2, new participants, who knew nothing about the composite images or where they came from, provided ratings of all four images in Figure 2. Images were rated, in a randomized order, on two main dependent variables: (a)
In addition, Phase 2 participants indicated the extent to which they felt warm (vs. cold) toward each image on a standard feeling thermometer scale, as well as the extent to which each image appeared “un-evolved” according to Kteily et al.’s (2015) Ascent of Human measure of blatant dehumanization. Feeling thermometer judgments were made on a scale from 0 =
Standardized Relationships Between Dependent Measures in Study 1.
Results
To analyze the data, dehumanization ratings in Study 1 were regressed, in a multilevel model, onto orthogonal contrasts that represented the 2 × 2 × 2 repeated-measures design of Phase 2’s rating study. The first factor in this model was whether images had been generated by
The research question of interest in Study 1 was whether liberals and conservatives cognitively emphasize different types of dehumanization when mentally representing one another. To examine this research question, dehumanization ratings of the mental representations obtained in Study 1 were subjected to the 2 × 2 × 2 model described above. This analysis revealed, first, a main effect of whether the mental representations were of political ingroup members versus political outgroup members. Mental representations of political outgroup members were rated as more dehumanizing (
To decompose the three-way interaction between generator ideology (liberal, conservative), representation type (ingroup, outgroup), and dehumanization dimension (savage, immature) described above, we conducted spotlight analyses to examine what all model effects looked like among ratings of ingroup representations and outgroup representations, respectively. Examining model effects among ratings of ingroup images revealed that both liberals and conservatives tend to mentally represent themselves as less dehumanized on the dimension of savagery (

Ratings of Composite Images (of Political Outgroup Members) in Study 1.
Discussion
The research question of interest in Study 1 was whether liberals and conservatives would differ in the types of dehumanization that they cognitively emphasize when mentally representing one another. Study 1 revealed that indeed, conservatives’ dehumanization of liberals emphasized immaturity more than savagery and that liberals’ dehumanization of conservatives emphasized savagery more than immaturity. These findings go beyond extant research on political dehumanization in that (a) these findings document political dehumanization measured implicitly (in mental representations) rather than explicitly (on self-report), and in that (b) these findings measure dehumanization not as a unitary construct (e.g., by using the Ascent of Human measure; Landry et al., 2021; Moore-Berg et al., 2020), but at the level of specific
Study 2
Whereas the focus of Study 1 was on political dehumanization, the focus of Study 2 was on political
Method
Study 2 occurred in two phases. In Phase 1, participants (half of whom were politically conservative and half of whom were politically liberal) called to mind their
Participants
Recruitment for Phases 1 and 2 was conducted via CloudResearch.com (Litman et al., 2017). As in Study 1, participants were adults living in the United States with a track record of high-quality survey responding (according to CloudResearch’s Approved Participant List). In addition, half of the participants in Phase 1 were required to have a track record of previously identifying either as “conservative” or as “very conservative”; the other half of participants in Phase 1 were required to have a track record previously identifying either as “liberal” or as “very liberal.” Demographics for all final participants from Phases 1 and 2 can be found in Table 3.
Final Participant Demographics (After Exclusions) From Study 2.
Phase 1 had an a priori goal of obtaining
Procedure
Phase 1
Participants in Phase 1 completed a 300-trial reverse-correlation task that was designed to approximate their
After the task was over, the research team computed composite images of the faces that liberals and conservatives, respectively, chose while calling to mind their meta-representations. For example, to create a composite image of conservatives’ meta-representation (i.e., how conservatives, on average, think liberals mentally represent conservatives), we created a morphed average of all the faces conservative participants chose during the reverse-correlation task (for conservatives’ and liberals’ respective meta-representations, see Figure 4, top row).

Composite Images of Meta-Representations (Study 2) Versus Outgroup Representations (Study 1).
Phase 2
In Phase 2, new participants provided ratings of four images in a within-person rating study: composite images of liberals’ and conservatives’ meta-representations (Figure 4, top row), as well as composite images of how liberals and conservatives actually represent one another (Figure 4, bottom row; note that these are the same images shown previously, in the bottom row of Figure 2). All four images were rated, in a randomized order, on the same two dependent variables described in Study 1: (a)
In addition, Phase 2 participants indicated the extent to which they felt warm (vs. cold) toward each image on a standard feeling thermometer scale (made on a scale from 0 =
Standardized Relationships Between Dependent Measures in Study 2.
Results
To analyze the data, dehumanization ratings in Study 2 were regressed, in a multilevel model, onto orthogonal contrasts that represented the 2 × 2 × 2 repeated-measures design of Phase 2’s rating study. The first factor in this model was whether images reflected representations of
The research question of interest in Study 2 was whether liberals and conservatives are sensitive to how they are represented in the minds of political outgroup members. To examine this research question, dehumanization ratings of the mental representations in Figure 4 were subjected to the 2 × 2 × 2 model described above. This analysis revealed, first, a two-way interaction between who was being represented in the images (conservatives vs. liberals) and whether the images were of meta-representations versus actual outgroup representations, two-way interaction: β = –0.32,
The findings above suggest that both liberals and conservatives may be inaccurate about the overall extent to which they are dehumanized in the minds of political outgroup members (i.e., the absolute magnitude of dehumanization). But are they at all accurate about the

Ratings of Composite Images (Meta- vs. Outgroup-CIs) in Study 2.
Discussion
The focus of Study 2 was on the question of whether liberals and conservatives are sensitive to how they are represented in the minds of political outgroup members. The findings of Study 2 suggest that in general, liberals and conservatives may be insensitive to how much they are dehumanized by political outgroup members: conservatives’ meta-representations underestimated actual outgroup dehumanization, whereas liberals’ meta-representations overestimated actual outgroup dehumanization. However, these findings also suggest that liberals and conservatives may be sensitive to
General Discussion
The reported studies were designed to weigh in on questions related to political dehumanization (Study 1) and political meta-dehumanization (Study 2), respectively. Rather than relying on self-report measures of dehumanization, which dominate the research literature on political (meta-)dehumanization, the present studies relied on an indirect method of assessing dehumanization: namely, reverse-correlation image classification (Dotsch & Todorov, 2012). The reverse-correlation task revealed, first, that liberals and conservatives both represented each other in dehumanizing ways, but that they differed in the dimensions of dehumanization that they cognitively emphasized. Whereas liberals’ dehumanization of conservatives emphasized savagery more than immaturity, conservatives’ dehumanization of liberals more strongly emphasized immaturity (vs. savagery). Second, the reverse-correlation task revealed that liberals and conservatives may have some insight into how they are represented in the minds of political outgroup members. Specifically, liberals’ and conservatives’ meta-representations appeared to accurately capture the relative amounts by which their respective groups are represented as savage versus immature by political outgroup members.
What are the implications of these findings? First, these findings suggest that liberals’ and conservatives’ dehumanization of each other may be underpinned by distinct cognitive belief systems—belief systems that emphasize savagery and immaturity, respectively. To the extent that liberals and conservatives diverge in the cognitive underpinnings of their political dehumanization, they may be expected to discriminate against each other in divergent ways (Kteily & Landry, 2022). For example, a tendency to represent liberals as immature might be correlated with discriminatory behaviors related to contempt: making derogatory remarks about liberals, decrying liberals’ reactions as overly emotional, not taking liberals’ perspective seriously when designing legislation, and the like. In contrast, a tendency to represent conservatives as savage might be correlated with discriminatory behaviors related to anger: verbally aggressing against conservatives, making policy recommendations that restrict conservatives’ autonomy, blaming conservatives for societal dysfunction, and the like. In general, contempt and anger are mutually reinforcing emotions that correlate with separate behaviors: behaviors related to belittlement and aggression, respectively (Fischer & Roseman, 2007). Future research should investigate whether immaturity- and savagery-based dehumanization, respectively, are indeed related to these divergent intergroup emotions, and in turn, to these divergent intergroup behaviors.
A second implication of these findings is that liberals and conservatives may not be as meta-perceptually oblivious as previously thought (Lees & Cikara, 2020; Moore-Berg et al., 2020). Instead, it may be the case that liberals and conservatives have a sense of
Open Questions for Future Research
An open question that these findings raise concerns how liberals and conservatives might respond to knowing how they are mentally represented by political outgroup members. According to past research, when partisans learn that they overestimate how dehumanized they are in the minds of political outgroup members, they themselves come to dehumanize the outgroup less (Landry et al., 2022). For example, when liberals learn that they overestimate how much conservatives dehumanize liberals, liberals themselves come to dehumanize conservatives to a lesser degree. A fruitful future direction for research on correcting meta-perceptions might be to investigate how liberals respond to learning both that they (a) overestimate how dehumanized they are in the minds of outgroup members, but that they (b) are nevertheless correct about the ways in which they are dehumanized (i.e., that they are indeed dehumanized along the dimension of immaturity more than savagery). On one hand, a two-sided message like this may cause liberals to regard this information as more credible than a message that emphasizes only the former, which could make that information more persuasive (Xu & Petty, 2022). On the other hand, a two-sided message like this may validate liberals’ beliefs that their meta-perceptions are accurate, which may undercut the persuasiveness of learning that they overestimate how dehumanized they are in the minds of outgroup members. Future research should examine which of these two possibilities holds up to scrutiny, as these possibilities have opposing implications for reducing animus between liberals and conservatives.
A second open question concerns how stable mental representations, as indexed by reverse-correlation image classification, may be across time. Studies 1 and 2 were based on two parallel studies, called Studies S1 and S2, that were conducted back in 2017 (see the online supplement for complete details). A comparison between Studies 1 and 2, on one hand, and Studies S1 and S2, on the other hand, is worth briefly considering in relation to the issue of representation stability. First, it is worth noting that the key findings highlighted in this article appear to have remained stable over time. Back in 2017, liberals and conservatives significantly differed in the extent to which they cognitively emphasized savagery versus immaturity when dehumanizing one another (though notably, the interaction pattern is stronger here than it was back in 2017), and liberals and conservatives were likewise meta-perceptually accurate with respect to
Limitations of the Present Work
A limitation of the present analysis is that it cannot be used to specify what causal relations exist between dehumanization in partisans’ mental representations, on one hand, and partisans’ expressions of intergroup animosity, on the other hand. For example, in the preceding paragraph, we suggested that total levels of partisan dehumanization, as indexed by mental representations, may fluctuate with time. Is it the case that fluctuations in intergroup animosity play a causal role in shaping fluctuations in partisans’ mental representations? Or is it instead the case that fluctuations in partisans’ mental representations play a causal role in shaping the levels of intergroup animosity they express? Ultimately, the present analysis cannot adjudicate between these possibilities, although our suspicion is that mental representations may be both caused by, and causally predictive of, intergroup animus. That is, dehumanization in one’s mental representations may be thought of as indexing partisan animosity that exists within a culture (for a similar argument, see: Payne et al., 2017), as well as driving partisans’ inclinations to express that intergroup animosity. More research is required on this particular point, however. To our knowledge, causal connections between one’s mental representations and one’s downstream behaviors, although theoretically reasonable, have not yet been established.
A second limitation of the present analysis is that even if implicit dehumanization
A third limitation of the present analysis is that it relies on reverse correlation, which is a somewhat recent psychological instrument whose properties are not fully understood (Cone et al., 2021). As such, it remains unclear to what extent properties of the instrument, or even properties of how people engage with the instrument, might have influenced the results reported here. For example, one property of the instrument that can influence corresponding results is which base image is used during the reverse-correlation task (Dotsch & Todorov, 2012). It is possible that data patterns reported here might have looked somewhat different if we had used an androgynous or racially ambiguous base image (e.g., Gallagher & Bodenhausen, 2021) rather than the White-male base image that we employed. Future research should examine to what extent partisan representations are shaped by the base image that serves as the foundation for those representations. A separate issue concerns how it is that people engage with the instrument. For example, although we prompted participants to choose whom they, personally, thought looked more like “a conservative” or “a liberal,” it is conceivable that they used cultural stereotypes to guide their image selections rather than their own personal beliefs. If cultural stereotypes were what was guiding participants’ selections—for example, stereotypes related to liberals seeming young or conservatives seeming masculine (e.g., Koch, 2000; Rothschild et al., 2019)—it could have been these stereotypes, rather than participants’ personally held views per se, that led to the observed emphases on immaturity and savagery, respectively. Future research should be dedicated to understanding whether reverse-correlation tasks measure participants’ idiosyncratic representations, as is commonly argued, or whether they instead measure participants’ impressions of cultural stereotypes. Such a distinction may have implications for how strongly individuals’ representations can be expected to correlate with individuals’ idiosyncratic behaviors.
Concluding Remarks
Political polarization is a quickly growing problem in the United States (Finkel et al., 2020). This problem is so severe that liberals and conservatives report feeling blatantly dehumanized by those across the aisle. This feeling, in turn, predicts reciprocal dehumanization of political outgroup members, and it predicts a willingness to subvert democratic norms out of spite for those across the aisle (Moore-Berg et al., 2020). If social scientists wish to prevent democratic norms from eroding in the United States, they need to better understand the psychological bases of political dehumanization and meta-dehumanization, respectively. The present studies were an attempt to do precisely that. Findings suggest that liberals and conservatives dehumanize each other along divergent dimensions, and that liberals and conservatives may be sensitive to the dimensions along which they are dehumanized. Thus, political dehumanization may not be as monolithic as previously thought, and liberals and conservatives may not be as meta-perceptually oblivious as previously thought. Our hope is that these insights can be leveraged to improve intergroup relations among liberals and conservatives—or at least, to prevent these relations from deteriorating further.
Supplemental Material
sj-pdf-1-psp-10.1177_01461672231180971 – Supplemental material for Political (Meta-)Dehumanization in Mental Representations: Divergent Emphases in the Minds of Liberals Versus Conservatives
Supplemental material, sj-pdf-1-psp-10.1177_01461672231180971 for Political (Meta-)Dehumanization in Mental Representations: Divergent Emphases in the Minds of Liberals Versus Conservatives by Christopher D. Petsko and Nour S. Kteily in Personality and Social Psychology Bulletin
Footnotes
Data Availability Statement
Declaration of Conflicting Interests
Funding
Supplemental Material
References
Supplementary Material
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