In the years leading up to the Rwandan genocide in 1994, radio stations controlled by Hutu extremists broadcast a steady stream of propaganda against the Tutsi minority. Because radio was the primary source of information in the country, these broadcasts played a significant role in shaping public attitudes and actions. In these broadcasts, the Tutsis were repeatedly referred to as Inyenzi, the Kinyarwanda word for cockroaches. They were described as cunning, dangerous, and subhuman. Broadcasters also accused the Tutsis of plotting to enslave the Hutu majority and steal their land.
The use of such language was deliberate. By describing Tutsis as insects rather than people, the propagandists dehumanized them and made violence against them easier to justify. The underlying message was that Tutsis were not people with whom the Hutu population could negotiate or whose concerns needed to be understood. They were portrayed as a threat that had to be eliminated.
In one hundred days, an estimated 800,000 people were killed. Ordinary people carried out much of the killing. Farmers, neighbors, and family members participated in the slaughter. The propaganda had helped transform the Tutsis from human beings into something portrayed as less than human, making it easier for ordinary people to overcome the moral barriers that would normally prevent them from killing other human beings.
This type of propaganda is a rhetorical device known as demonization. Demonization goes beyond criticism and scapegoating. It involves portraying an opponent or a group as evil, dangerous, or less than human. The goal is not to win a logical argument, but to place the target outside the boundaries of normal moral consideration.
The structure of demonization exploits a specific weakness in human reasoning: it bypasses the intellectual burden of proof by triggering a primal survival instinct. The target is stripped of their humanity and described in terms that evoke disgust, fear, or hatred. They are portrayed simply as enemies of all that is good and as threats that must be eliminated. When we believe we face an existential threat, we become less willing to evaluate evidence, question the policies of the speaker, or consider alternative explanations.
Psychologist Philip Zimbardo identified dehumanization as an important step in understanding how ordinary people can come to commit atrocities. In his book The Lucifer Effect, he described how this process works. Once a group is portrayed as animals, vermin, or demons, people no longer see them in quite the same way as other human beings. The normal restraints against harming another person begin to weaken. People who would normally never hurt a fellow human being can become capable of terrible acts against those who have been deliberately portrayed through propaganda as less than human.
Once an audience has come to see a group as demons, ordinary rules of logic and morality no longer apply. We do not compromise with demons. We do not look for common ground with people we have been told are evil. The only response left is complete opposition.
Demonization has been a feature of political life throughout history.
During World War I, propaganda portrayed Germans as Huns. They were depicted as barbarians who bayoneted babies and committed atrocities. Atrocities do occur in war, but the propaganda went beyond documenting factual events. It sought to create an image of the enemy as inherently savage and incapable of civilization or mercy. The political scientist Harold Lasswell analyzed this tactic in his 1927 study Propaganda Technique in the World War, showing how systematic demonization bypassed rational debate and mobilized entire populations for total war.
In Nazi Germany, Jews were systematically portrayed as vermin, parasites, and a disease infecting the body of the nation. Propaganda posters depicted them with exaggerated features, lurking in shadows, and corrupting innocent citizens. The language and imagery were designed to provoke disgust and fear, with the objective of making ordinary Germans see their Jewish neighbors as something other than human. The historian Claudia Koonz has documented in The Nazi Conscience how this propaganda prepared the way for genocide by making Jews seem unworthy of moral consideration.
In the 1947 Partition of India, communities that had lived together for generations turned on each other with violence fueled by propaganda that portrayed the opposing community as an existential threat. Muslims were told that a Hindu-majority government in an undivided India would subjugate them and strip away their security. Hindus and Sikhs were told that Muslims intended to eradicate them from the newly proposed territories of Pakistan through forced conversion or slaughter. Each side was encouraged to see the other not as neighbors with real political concerns, but as mortal enemies. Once the other side was no longer seen as fully human, the killing followed.
Throughout the Cold War, both sides demonized the other, which made it harder to deal with each other through negotiation. In the United States, communists were portrayed as agents of an evil empire bent on destroying freedom and enslaving the world. In the Soviet Union, capitalists were depicted as bloodsuckers exploiting the working class, devoid of any human decency. Each side saw the other as a mortal threat that could not be reasoned with, and any evidence contradicting these rigid views was quickly dismissed as enemy propaganda.
In China, the state orchestrated a campaign against intellectuals, teachers, and perceived political enemies during the Cultural Revolution, officially labeling them as "cow demons and snake spirits." This mythological terminology was deliberately chosen to strip political targets of their humanity. By branding political opponents as monsters, the state empowered student militias to publicly humiliate, imprison, and kill their neighbors and teachers. The demonization bypassed the legal system and justified violence against anyone deemed a threat to the ideology.
In the labor movements of the early twentieth century, union leaders sometimes portrayed factory owners as heartless monsters with no concern for the workers' suffering. The owners, in turn, portrayed union organizers as dangerous agitators bent on wrecking the economy. Each side attacked the other rather than negotiate over the real demands, such as wages, hours, and working conditions. And once each side had stopped seeing the other as fully human, sitting down to negotiate became very hard.
Research on intergroup conflict shows that demonization follows predictable patterns. The psychologist Gordon Allport set out the stages by which prejudice escalates in his 1954 book The Nature of Prejudice. He described a progression from hostile talk to avoidance, then discrimination, then physical attack, and finally extermination. Demonization is what moves a group from one stage to the next. Each stage becomes easier once the target has been portrayed as less than human.
The linguist George Lakoff analyzed how metaphors shape human thinking about groups. When speakers describe people as animals, parasites, or diseases, they activate mental frameworks associated with those categories. Animals can be hunted. Parasites must be eliminated. Diseases must be eradicated. The metaphors carry hidden logical implications. They shape how we think about appropriate responses, subtly justifying violence.
Demonization is a barrier to critical thinking because it closes off the possibility of resolution. If an opponent is wrong, we can argue with them, persuade them, or reach a compromise based on evidence. If an opponent is evil, none of these options remain. The only response to evil is to defeat it. This is why demonization often leads to violence. Once a group is placed outside the boundaries of moral consideration, harming them becomes framed as a righteous act. The propagandists in Rwanda understood this mechanism. The Nazis understood it. Every movement that has sought to justify atrocities against a targeted group has relied on it.
Demonization also damages our own thinking when we do it. Once we demonize our opponents, we lose the ability to understand any other point of view. We cannot learn from the other side, because we have already decided that nothing the enemy says is worth anything. We cannot correct our own mistakes, because anyone who points them out can be waved away as an agent of the enemy.
Strong disagreement is part of public life. Harsh criticism based on facts is a fair tool of debate. But when criticism turns into demonization, clear reasoning stops. Dehumanizing language usually comes before the worst things people do to one another. Disagreement acknowledges the humanity of the opposition. Demonization is the active refusal to see humanity in those who hold a different view.
When we come across an argument that describes a person or group in language that denies their humanity, calling them vermin, parasites, an infection, or simply evil, the useful response is to stop and look hard at the words. Is this a factual description of what the group has done, or is it language chosen to make us stop seeing them as human? A speaker with a real case can make it in plain terms. Someone who uses dehumanizing labels instead usually has a different intention: to dehumanize.
The defense is to name what is happening. Demonization works by getting past our reasoning: once a group has been cast as evil, we stop weighing evidence about them and simply oppose them. Naming the tactic out loud, recognizing that a speaker is demonizing rather than arguing, restores the step that demonization removes. It forces the question back into the open: what has this group actually done, and does the evidence support it?
This chapter is from Barriers to Critical Thinking by A.S. Prasad- a book scheduled to be published in October 2026