Radio Télévision Libre des Mille Collines went on the air in Rwanda in July 1993. It was popular, and deliberately so: it played Zairean pop music, its presenters were funny and profane, and it sounded nothing like the stiff state broadcaster. Young men listened to it in bars and on the street.
It also called Tutsi inyenzi — cockroaches — and inzoka, snakes. Continuously, for nine months, alongside the music.
When the killing began in April 1994, RTLM read out names and locations. It told listeners where people were hiding, congratulated militia on their work, and instructed that the graves were not yet full. Its role was established in evidence at the International Criminal Tribunal for Rwanda, where three media figures were convicted; the Nahimana appeal judgment narrowed some findings on causation while affirming that the broadcasts constituted incitement.
The choice of vermin is not incidental, and the mechanism is specific.
Disgust is an emotion that evolved for pathogen avoidance. Its behavioral output is rejection, expulsion and cleansing, and unlike anger it does not treat its object as an agent with whom one has a dispute. Anger says you have wronged me. Disgust says you should not be here.
David Livingstone Smith's work on dehumanization argues that the vermin metaphor does something more specific than insult: it reclassifies the target as a different kind of creature, subhuman rather than merely bad, and moral obligations that attach to persons do not attach to it. Lasana Harris and Susan Fiske's neuroimaging work found that when subjects viewed images of extremely dehumanized groups, the medial prefrontal cortex — reliably activated when thinking about other people's minds — showed reduced activation relative to other social targets. The finding has been debated and refined since, and should not be over-read, but it is consistent with a large behavioral literature: dehumanizing language reliably reduces the moral protections extended to its targets.
Once the label is in place, the act is reframed. Killing becomes sanitation. The vocabulary of the Rwandan genocide is full of it — go to work, clear the bush, cut the tall trees. Bandura's moral self-sanctions do not fire, because the categories they operate on have been changed.
The pattern is not confined to Rwanda, which is the reason this chapter is in a guide rather than a history. Nazi propaganda used vermin and disease imagery for Jews systematically. Anti-immigrant rhetoric across many countries has used infestation, swarm, and plague. The vocabulary of ethnic cleansing is itself hygienic.
Which gives the single most reliable early-warning indicator in this entire guide, and it is worth stating without qualification.
When a group of people is publicly described using words for animals, insects, disease, dirt or contamination, by people with access to a broadcast platform, that is not merely offensive speech. It is the specific linguistic precondition that precedes organized violence, it appears in the record before every case we have, and it is doing identifiable psychological work on the audience while it appears.
Cross-ref: Part 7 incitement and propaganda