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29 dehumanization
April 25, 2019+Sean Stevens
+Public Policy

Partisan Dehumanization in American Politics

Over the past decade, concern over how extremist political communities can employ social media to promote their views and incite violence has increased. The Dangerous Speech Project defines dangerous speech as “any form of expression (e.g., speech, text, or images) that can increase the risk that its audience will condone or commit violence against members of another group.” One of the hallmarks of dangerous speech is dehumanization, the process of classifying rival outgroups as subhuman so that derogation, prejudice, and even violence against them can be justified and rationalized.

Research on dehumanization has a long history in social psychology (see Bandura, Underwood, & Fromson 1975). Since a person can dislike a group and its members without denying their fundamental humanity, dehumanization and prejudice are considered distinct concepts, although they can co-occur within an individual (Haslam & Stratemeyer 2016).

Much scholarship in this field has focused on how dehumanization has been used to justify and rationalize prejudice and derogation of racial and ethnic groups, immigrants, and refugees (e.g., Ellemers 2017; Lajevardi & Oskooii 2018; Utych 2018). Less attention has been given to how dehumanization may occur between rival political groups and thus contribute to political divisiveness; recent research by Erin Cassese addresses this gap.

Cassese investigated two questions: Do partisans demonstrate evidence of dehumanization when asked to assess the opposing party? And, if there is evidence of dehumanization, does partisan identity strength moderate its effect? Four hypotheses were specified:

  1. Partisans will rate their own party as significantly more human than the opposing party.
  2. Dehumanization of one’s political opponents is greater among strongly identified partisans.
  3. Dehumanization of the opposing party is associated with a preference for increased social distance from one’s political opponents.
  4. Dehumanization of the opposing party is associated with perceptions of increased moral distance from one’s political opponents.


To investigate these four hypotheses, a student sample (N = 397) and a Mechanical Turk sample (N = 609) were collected in October of 2016.

Two kinds of dehumanization were measured, subtle dehumanization and blatant dehumanization. Research postulates that subtle dehumanization can take two forms:

  1. Animalistic dehumanization signals a denial of human uniqueness (e.g. *those people* are uncouth, stupid, deplorable).
  2. Mechanistic dehumanization signals a denial of human nature traits (e.g. *those people* are robotic, unemotional, impersonal). Participants evaluated Democrats and Republicans on 10 animalistic traits (e.g., humble, polite, cold, hard-hearted) and 10 mechanistic traits (e.g., passionate, sociable, jealous, aggressive).

Blatant dehumanization was measured with the Ascent of Man scale (see Kteily, Bruneau, Waytz & Cotterill 2015). Participants rated both parties on a scale anchored by 5 images corresponding to the evolution of man, ranging from subhuman to human. Responses were standardized and composite scores measures were created, with higher scores indicative of more dehumanization.

Identity strength was measured with a four-item partisan identity scale developed by Huddy, Mason, and Aarøe (2015). This measure is informed by social identity theory and is designed to provide a more granular measure of identity strength. For instance, participants were asked “How important is being a [Democrat/Republican] to you? And, “When talking about [Democrats/Republicans] how often do you use ‘we’ instead of ‘they’?” A standardized composite measure was created, with higher scores indicative of greater identity strength.

Social distance was measured with two items: “Suppose a son or daughter of yours was getting married. How would you feel if he or she married a supporter of the [Democrat/Republican] Party?” And, “If you are single or weren’t already married, imagine yourself marrying a supporter of the [Democrat/Republican] Party. How do you think marrying a supporter of this party would make you feel?” A standardized composite measure was created, with higher scores indicative of a preference for greater social distance.

Finally, moral distance was measured by asking participants how different Democrats and Republicans are from each other on morality, honesty, trustworthiness and sincerity. A standardized composite measure was created, with higher scores indicative of a perception of greater moral distance.

Standard demographic questions were also included.


In both the student sample and the Mechanical Turk sample, evidence of subtle and blatant dehumanization emerged among partisans, lending support to hypotheses 1 and 2. Democrats and Republicans, in both samples, engaged in animalistic dehumanization, mechanistic dehumanization, and blatant dehumanization. As can be seen below, these effects were the most pronounced among the most strongly identified partisans:

The regression model that tested hypotheses 3 and 4 included the demographic variables and blatant dehumanization as predictor variables. The two subtle forms of dehumanization were not included as predictors due to collinearity with blatant dehumanization. Results suggest the evidence for partisans preferring greater social and perceiving more moral distance was mixed. In terms of social distance, there was evidence of a preference for greater social distance among partisan Democrats in the Mechanical Turk sample and, among partisan Republicans in the student sample. Partisan Democrats in the student sample also reported a preference for greater social distance, although this effect was quite small. Partisan Republicans in the Mechanical Turk sample did not report a preference for greater social distance.

When it came to a perceiving greater moral distance between the parties, Partisan Democrats and Partisan Republicans in both samples all perceived greater moral distance between the parties. These findings lend support to hypothesis 4, and suggest there is a moral dimension to partisan dehumanization.


Although the process of dehumanization has not received much attention in political science, it has received a good deal of attention within social psychology. Although this has provided a number of insights into how people dehumanize racial and ethnic groups, immigrants, and refugees, research on the dehumanization of rival political groups has been scant.

Nevertheless, research on dehumanization indicates that the process is associated with moral disengagement whereby a person or group are classified as less than human, and thus less deserving of moral consideration. In other words, when a rival person or group is dehumanized they are seen as undeserving of moral concern. When this occurs, unfair treatment, derogation, and even aggression are then easily justified and rationalized (see e.g., Ellemers 2017; Schwartz 2007). Once this process is underway it may become self-reinforcing, as research indicates perceived dehumanization prompts dehumanization as a response (Kteily, Hodson & Bruneau 2016).

The present research can be added to a small, but quickly growing, body of literature that has documented dehumanization (see Kteily & Bruneau 2017; Pacilli, Roccato, Pagliaro & Russo 2016) and partisan moral disengagement (Kalmoe & Mason 2018) in the political realm. Data from a student sample and a Mechanical Turk sample, collected closely before the 2016 Presidential Election, demonstrate that both Democrats and Republicans engage in subtle and blatant dehumanization of their political rivals — and perceive a considerable moral distance between Democrats and Republicans. These effects most pronounced among partisans strongly identified with their party.

What Do These Findings Mean?

Cassese suggests that dehumanization has often been overlooked as a component of intergroup bias and derogation in the political domain. Indeed, much of the research on intergroup bias within the political domain has focused on affective partisanship and affective polarization, and found it is driven by the strongest partisans (see Huddy et al. 2015; Iyengar Sood & Lelkes 2012; Iyengar & Westwood 2015). The current results are consistent with these findings and extend them to the realm of dehumanization. The strongest partisans dehumanize their political rivals far more than weaker partisans do.

Other scholarship has found that outgroup derogation is considered a legitimate means of challenging political opponents (Combs, Powell, Schurtz & Smith 2009) and that dehumanization may be a self-reinforcing process (Kteily et al. 2016). When these findings are considered in conjunction with Cassese’s results, they suggest the American political landscape is fractured and may be at risk for even greater polarization — threatening the continued functioning, viability and political legitimacy of our political and civic institutions (as well-described in a recent New York Times columnby Thomas Edsall that provides links to much more research in this area).

To counteract these trends, citizens should heed the advice of people like Arthur Brooks and Christian Picciolini, who both urge us to keep our contempt in check and learn to love our political “enemies.”

Reference: Cassese, Erin (2019). “Partisan dehumanization in American politics.” Political Behavior. DOI: 10.1007/s11109-019-09545-w

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