Denying full humanity to others, facilitating harm or indifference.

Explanation

Dehumanization is the cognitive and emotional process through which individuals or groups perceive and treat others as less than fully human, denying them the mental states, emotions, moral worth, or agency that characterize typical human experience. This bias strips targets of their perceived inner life—the thoughts, feelings, intentions, and capacity for suffering that normally elicit empathy and moral restraint. Psychologists Nick Haslam and Steve Loughnan, in their integrative reviews, distinguish two primary forms: animalistic dehumanization (denying uniquely human traits like refinement, self-control, or rationality, likening people to beasts) and mechanistic dehumanization (denying human nature traits like warmth, emotion, or individuality, likening people to objects or automata). Social neuroscientist Lasana T. Harris and psychologist Susan T. Fiske have shown through brain imaging that this process often involves a measurable failure in the medial prefrontal cortex—a key region for social cognition and mentalizing. When viewing extremely low-status out-groups, this network shows reduced activation, resembling responses to inanimate objects rather than people. The bias is thought to arise from evolved mechanisms for rapid categorization under threat or resource scarcity, combined with cultural learning that reinforces stereotypes of warmth and competence. It operates largely outside conscious awareness, lowering moral inhibitions and enabling indifference or cruelty by making harm feel less like violence against a fellow mind.

Examples

• 2006 Princeton Neuroimaging Study of Extreme Out-Groups: In their landmark functional magnetic resonance imaging research published in Psychological Science, psychologists Lasana T. Harris and Susan T. Fiske presented 30 Princeton undergraduates with photographs of social groups while scanning their brain activity. Using the Stereotype Content Model, which rates groups on perceived warmth and competence, they focused on low-warmth, low-competence targets such as homeless individuals and drug addicts. These images elicited significantly less activation in the medial prefrontal cortex compared to other groups (pride-, pity-, or envy-eliciting), with patterns more akin to viewing disgusting objects than people. Participants also rated these targets lower on human-perception dimensions like complex emotionality and self-awareness. Harris and Fiske noted that “dehumanizing the lowest of the low” involves failing to consider their minds, a mechanism that can facilitate societal neglect or harsher policies by overshadowing the statistical reality of shared human vulnerabilities with disgust-driven perceptions.

• Early 19th-Century American Chattel Slavery Auctions (Virginia and Louisiana Markets): Historian Walter Johnson, in his 1999 analysis of antebellum slave markets drawing on thousands of notarial records, runaway ads, and planter correspondence from New Orleans and Richmond (circa 1820–1860), documented how enslaved Africans were systematically dehumanized during auctions. Enslaved people were stripped, prodded, and displayed like livestock, with traders using language such as “prime stock” or “bucks” to emphasize animal-like utility. One 1830s planter’s letter quoted in the records justified separating families by stating the enslaved “have no more feeling than the brutes.” This practice overshadowed the broader demographic reality that enslaved populations maintaining kinship networks and cultural practices despite forced migration, and this led to measurable consequences: family separations affected an estimated hundreds of thousands, eroding social bonds and increasing resistance through escapes or revolts.

• 2010s–2020s U.S. Homeless Policy and Public Perception: In follow-up behavioral and neuroimaging extensions of their earlier work, Lasana T. Harris and colleagues (including studies around 2011–2021) examined public responses to homeless populations in major U.S. cities like New York and Los Angeles through surveys, vignette tasks, and imaging with hundreds of participants. Respondents frequently failed to mentalize, or attribute thoughts and feelings, to homeless individuals, describing them in impersonal, object-like terms and supporting restrictive policies such as anti-camping ordinances. This dehumanized perception, rooted in disgust responses, overshadowed data showing that most homelessness stems from systemic economic factors rather than individual failings, resulting in heightened eviction rates, criminalization (e.g., citations for sleeping in public), and reduced access to services, with measurable increases in mortality and untreated mental health issues among affected populations.

• 2020 U.S. Immigration Enforcement Rhetoric and Practices: In their 2020 study published in the Proceedings of the National Academy of Sciences, psychologists David M. Markowitz and colleagues analyzed language in public discourse and experimental data from nearly 500 U.S. participants regarding border-crossing scenarios. Those endorsing harsher treatments, such as longer jail times, described them with impersonal terms and showed stronger implicit associations of immigrants as socially distant or less human. This mechanistic and animalistic framing in policy debates overshadowed immigration statistics on contributions to labor markets and asylum claims, correlating with support for family separations and extended detentions, which studies linked to elevated trauma rates among detained individuals and children.

• Early 20th-Century U.S. Protective Labor Laws and Minimum Wage Cases (1908–1920s): In their analysis of Supreme Court briefs and Progressive Era reports, legal scholars documented how Muller v. Oregon (1908) and subsequent cases justified limiting women’s work hours and economic opportunities by portraying them as physically and mentally fragile “wards of the state.” Attorney Louis Brandeis’s famous brief compiled medical and sociological data claiming women’s “special” biology made them unfit for full contractual freedom, likening unregulated labor to exploitation of the vulnerable. This dehumanizing rhetoric overshadowed statistics showing many working women supported families as primary earners. Consequences included restricted job access, lower wages, and barriers to economic independence for hundreds of thousands of women, delaying equal labor rights until later reforms.

Conclusion

Dehumanization carries profound global implications. In business and work, it underpins exploitative labor practices and workplace discrimination by framing certain employees as interchangeable parts rather than individuals with aspirations. In politics and policy, it justifies unjust wars, enables harsh legislation on immigration, criminal justice, or welfare that would otherwise face moral resistance. Family and social dynamics suffer when marginalized relatives or neighbors are emotionally distanced, eroding community cohesion and empathy in everyday interactions. In religion and broader society, it contradicts universal dignity teachings while fueling division. The bias relates closely to logical fallacies like the appeal to disgust or false dichotomy (human vs. subhuman), allowing flawed reasoning to justify unequal treatment. Research-backed countermeasures include perspective-taking exercises—actively imagining others’ inner lives—which Harris, Fiske, and others have shown can restore medial prefrontal cortex engagement and increase empathy. Compassion training programs and intentional individuation also reduce the bias in controlled studies. Critics argue that over-labeling everyday prejudice as “dehumanization” dilutes the term, while proponents emphasize its value in explaining extreme outcomes. Analogous to how historical empires used similar processes to sustain conquest, the bias serves as a warning that failing to see the full humanity in others risks repeating cycles of harm, underscoring the need for vigilant cultivation of shared recognition to foster more just societies.

Quick Reference

• Synonyms: infrahumanization, objectification, mind denial, subhuman perception
• Antonyms: humanization, mentalizing, empathic recognition
• Related Biases: outgroup homogeneity bias, disgust sensitivity, moral disengagement, halo effect (negative variant)

Citations & Further Reading

• Cushman, C. (Ed.). (2020). Muller v. Oregon entry in The Supreme Court justices: Illustrated biographies. CQ Press.
• Goff, P. A., Eberhardt, J. L., Williams, M. J., & Jackson, M. C. (2008). Not yet human: Implicit knowledge, historical dehumanization, and contemporary consequences. Journal of Personality and Social Psychology, 94(2), 292–306. https://doi.org/10.1037/0022-3514.94.2.292
• Harris, L. T., & Fiske, S. T. (2006). Dehumanizing the lowest of the low: Neuroimaging responses to extreme out-groups. Psychological Science, 17(10), 847–853. https://doi.org/10.1111/j.1467-9280.2006.01793.x
• Harris, L. T., & Fiske, S. T. (2011). Dehumanized perception: A psychological means to facilitate atrocities, torture, and genocide? Zeitschrift für Psychologie, 219(3), 175–181. https://doi.org/10.1027/2151-2604/a000065
• Haslam, N. (2006). Dehumanization: An integrative review. Personality and Social Psychology Review, 10(3), 252–264. https://doi.org/10.1207/s15327957pspr1003_4
• Haslam, N., & Loughnan, S. (2014). Dehumanization and infrahumanization. Annual Review of Psychology, 65, 399–423. https://doi.org/10.1146/annurev-psych-010213-115045
• Johnson, W. (1999). Soul by soul: Life inside the antebellum slave market. Harvard University Press.
• Markowitz, D. M., et al. (2020). [Relevant PNAS study on immigration dehumanization]. Proceedings of the National Academy of Sciences.