We are familiar with the medieval trope of heads on pikes and the revolutionary guillotine lopping off aristocratic heads. Social science calls this sort of public display “exemplary punishment.” The spectacle is designed to inspire fear and awe in a population. Roots of this behavior run as deep as time: abundant archaeology has established that decapitation and head display were European practices emerging from the Paleolithic, though the context is not always clear. For the motives will vary by time and circumstance, while the usual mix of human motivations are always present, too.

Lopping off a head doesn’t necessarily count as disrespect; indeed, it can mean the opposite. Ancestor veneration in prehistory may have carried over into the Middle Ages practice of venerating the skulls of saints, for example. Aggressive head-taking has its own contextual meanings: the hero takes the head of an enemy home in order to raise his own status either by denigrating the vanquished, or by exalting them. As with the guillotine, the act is inherently political, a revision or reassertion of individual and group hierarchies. Put another way, trophy-taking and corpse display are vocabulary from a universal language of violence. If there is a more visceral way of signposting exclusion, or of impressing your neighbors so that they defer to your authority, I have not heard of it. No human culture lacks an understanding of what decapitation means for the victim, or for their group.

Pacific Islanders are not unusual at all in headhunting. The cultures of southeast Asia and Oceania have sharply refined the practice of taking heads, endowing it with a variety of rituals and meanings at various times, but they are hardly alone in this global form of communication. Public display of the heads of executed traitors and criminals was still a gruesome practice in the Low Countries when Dutch merchant adventurers arrived in the Indonesian archipelago during the 17th Century, so no one had to explain to them what head-display meant. When “Enlightenment” Europeans expressed repulsion or fascination at the “barbaric” headhunting behavior of “primitive” people, head and corpse display still had political meaning in their own countries. During the 19th Century, when the Dutch colonial project extended from its small enclaves to embrace the archipelago, their mere presence transformed headhunting ritual into a form of symbolic resistance against themselves.

Imperialists intuited all of this. Whenever punitive raids descended upon hamlets or villages, they would confiscate racks of preserved heads, usually for sale as souvenirs in “civilized” places. Because heads were a currency of power in the region, this appropriation always damaged local power structures. On Borneo, for example, a rack of heads has always signaled the owner’s social and political position within traditional hierarchies. On Sumba Island, the heads of defeated enemies were held until the war or feud ended, whereupon they were buried. Such a symbolic emasculation of the community and its elites usually resulted in their taking new heads from neighboring communities in order to erase their humiliation by the colonial power. When British naval officer Lt. Boyle T. Summerville took an extended tour of the Solomon Islands in the 1890s, he recorded plummeting island populations as a metaphorical tsunami of headhunting washed over the region. Such were the fruits of bringing “civilization” to “primitive” peoples.

Contemporary academic works on Indonesian headhunting stress that heads usually have not come from defeated warriors. On the contrary: old people, women, and children seem to be perfectly acceptable targets of convenience for most headhunters, who are only seeking ritual objects in the first place. During the late 19th Century, as Christian missionary activity increased on Sulawesi, practitioners of mappurondo actually replaced heads with coconuts; the ceremony of the headhunt endures even when the literal headhunt has been abandoned. For symbolic killers, murder is not the point. Even the meaning of the symbolic act changes over time. In today’s Indonesia, a figure like Wona Kaka — the Sumbanese headhunter who led a rebellion against Dutch rule in the early 20th Century — is seen by many as a symbol of resistance to the centralized Indonesian state.

Archaeologist Ian Armit explains that these practices are about resolving “the perennial problem of how we distinguish enemy from ancestor.” Although Indonesia is a diverse nation, ancestry still matters, especially in lean times. The economic turmoil that brought an end to Suharto’s reign in 1998 also resulted in lethal unrest on Borneo in 1999 and 2001. During these episodes, Dayaks decapitated Madurese and put their heads on prominent display at the entrances to Dayak neighborhoods. Unable to affect the global economic forces squeezing them, the Dayaks asserted dominance over their traditional rivals instead, marking the boundaries of community. Likewise, traditional uplanders in the South Sulawesi peninsula headhunted coastal peoples into the 20th Century because the latter group had better access to the goods that Dutch empire made available. Thus, resource imbalances between groups clearly play a role in the occasional resurgence of headhunting.

Nevertheless, islanders on Borneo and Sarawak decapitated Japanese soldiers as they fought for the allies during World War II, while many Japanese officers took pride in their decapitating sword strokes, and none of it served any economic purpose. Territory and control were the issues being debated in the exchange of heads.

So it should not surprise us that heads, corpses, and other trophies appeared on public display in various parts of Indonesia from 1965-1966, a gruesome messaging campaign aimed at excluding and terrorizing the Indonesian left. Headless bodies floated in bloodstained rivers under bridges where heads were displayed on bamboo poles; heads would be removed at death, or after death; they were seen riding atop poles mounted on jeeps, in place of flags; paramilitary men amused themselves by frightening the townsfolk with grisly prizes. During the first phase of the genocide, corpses were routinely left where they could be seen. Sexual organs — breasts, penises, testicles — were removed and displayed as well, particularly in the vicinity of the meeting-houses where the youth gangs gathered.

All of this “exemplary violence” was aimed at excluding the Partis Komunis Indonesia (PKI) from the Indonesian nation. It worked. Exemplary murder and corpse display drove hundreds of thousands of people to turn themselves over to the Army, which then handed them over to the death squads in batches during the second phase of the killings. These killers were civilian recruits. They were armed, organized, and directed by the Indonesian army. No gas chambers were used in this genocide. Instead, the majority of the murder was personal, at arm’s length. Witness and perpetrator accounts indicate that decapitation was common in these killings. Headless bodies went into holes and ditches, then sometimes the heads were taken elsewhere; other times, they were simply left with the body. Some victims were shot, others garroted, still others dispatched with clubs, before they were also decapitated with machetes.

The context of headhunting varies. Mappurondo rituals are connected to the rice harvest and the trade season, for example. But this killing season was total war, an echo of Borneo, Sarawak, and Luzon islander resistance to Japanese occupation. Sukarno’s nationalizing, anti-western policies had led to runaway inflation and food insecurity. Indonesia was in danger, and only the blood of communists could possibly save the nation.

Army propaganda deepened the sense of threat by inventing an imminent genocide of non-communists that supposedly justified the brutal murder, torture, rape, and abuse of communists. Reinforced by western media broadcasts into the country, this fabricated narrative endorsed the frenzy, which the western media then framed for its own audiences as the madness of crowds — a people “run amok.” One of a handful of Malay words that has entered the English language, amok is a Javanese trope of sudden, suicidal violence tinged with revenge. By misusing the word, western reporters conveniently dodged the assignment of responsibility for the violence. Cold War disregard for the lives of communists did the rest. After all, were communists really even human?

It is a commonplace of genocide studies that propaganda serves to dehumanize the victims in the eyes of the perpetrator. Indonesia is no exception, and this is reflected in the nature of the headhunting that took place. Another observation from the Holocaust is that most human beings are only capable of killing a limited number of people; few headhunters are truly prolific. This may help explain why the first phase of the 1965 genocide lasted just three months, while the second stage in the new year required the Army to mobilize ideological recruits with secret rituals of murder.

By March of 1966, Suharto had destroyed the PKI and Sukarno’s own party, and he was purging the bureaucracy. Sukarno had lost his power to “guide democracy” or “mobilize the masses.” Marginalized, replaced, and finally put under house arrest in 1967, the Father of the Nation was reduced to a head in Suharto’s collection, consumed and hidden, subordinated as a symbol of his own authority.