Tribal skulls and the complex culture of the Asmat of southwestern New Guinea
‘Asmat’ is a term synonymous with headhunting and cannibalism, the name of a primitive ethnic group inhabiting the remote southwest of New Guinea, an inhospitable terrain of swamps and mangroves bordering the Arafura Sea.
Skulls have played a pivotal role in Asmat culture, both as symbols of reverence honouring deceased ancestors and as objects representing retribution against a defeated enemy.
The Asmat are believed to have hunted for heads until perhaps the 1980s or 90s. Modern civilisation did not touch them until relatively recently. Christian missionaries began the difficult process of persuading the Asmat to cease headhunting in the 1950s. Some converted to Christianity, but not all.
Traditional Asmat culture is based around ancestor worship and a belief that all deaths – except those of the very young or very old – are the result of malevolent acts arising through magic or physical force and therefore demand vengeance. The spirits of the dead linger around their home village until avenged, a belief that led to a continuous cycle of reciprocal violence between villages.
Headhunting raids were an important element of Asmat culture, and the taking of a human head was a necessary rite of passage in the rituals through which boys were initiated into manhood
There has been a persistent rumour that Michael Rockefeller, fifth son of Governor Nelson Rockefeller, was killed and eaten by the Asmat in 1961. Twenty-three-year-old Michael, recently graduated from Harvard, visited the Asmat region to collect tribal artefacts for the Museum of Primitive Art in New York, founded by his father.
Michael disappeared without a trace after attempting to swim to shore from his swamped catamaran, leaving a companion, Dutch anthropologist Renee Wassing, aboard the disabled craft. Wassing survived, but Michael Rockefeller was never seen again. The official explanation is that Michael drowned, or was eaten by sharks or saltwater crocodiles. But some enquiries suggest that he met an even more gruesome fate at the hands of headhunting Asmat cannibals.
Asmat skulls – ndambirkus and nadaokus
The skulls of honoured and important ancestors were kept in a secure place to be venerated and presented during special ceremonies – and sometimes used as headrests so that the living could remain connected to the dead.
These revered objects are known as ndambirkus and are richly decorated, the lower jaw being firmly attached with rattan binding.
The eye sockets and nasal cavity were filled with beeswax, to prevent evil spirits from entering the skull, and often decorated with seeds – red Crab’s eye (abrus precatorius) and grey Job’s tears (coix lacryma-jobi) – pressed into the beeswax.
Sometimes the nasal area was adorned with an object known as a ‘bipane’, a curved facial ornament fashioned from a cymbium shell (sea snail), which Asmat warriors wore through their pierced septums. Further decoration included cockatoo and sometimes cassowary feathers attached to a band over the top of the skull, also decorated with abrus and coix seeds.

Asmat ndambirkus ancestor skull, with bipane nose ornament and lower jaw attached, decorated with seeds and cockatoo feathers.
Enemies killed in revenge raids were cannibalised and their heads taken as trophies, known as ndaokus. These were treated with much less respect and kept in the central men’s house (termed a jeu) as proof of prowess in battle. Ndaokus can be found decorated similarly to ndambirkus, but may also be left unadorned.
Ndaokus have two features that make them distinguishable from ndambirkus. The ndaokus war trophies always have a hole in one temple, through which the brain matter of the enemy was removed for cannibalisation.
In addition, ndaokus skulls lack the mandible. The lower jaw of a slain enemy was removed and given to the women of the village, as an ornamental trinket – a final humiliation and insult towards a defeated victim.

Asmat ndaokus enemy skull, showing hole in temple and lacking lower jaw
So – in theory – Asmat ndambirkus and ndaokus are easy to differentiate. However, it is quite usual to find ndambirkus that lack the lower jaw, simply because the rattan binding securing jaw to skull has rotted away and the jaw has become detached and lost over time. The one certain clue that an Asmat skull is an ndaokus enemy skull is the evidence of a hole in one temple through which the brain matter was removed.
An Asmat skull was recently offered for sale at a UK auction – lacking the lower jaw but without the telltale hole in the temple. So, it was undoubtedly an ndambirkus ancestor skull, despite there being no lower jaw present.
Was the disappearance of Michael Rockefeller ever solved?
The answer is ‘possibly’. The Rockefeller family has never accepted any explanation other than that Michael drowned trying to swim to shore from his foundering catamaran.
After exhaustive documentary research, the acclaimed travel writer, Carl Hoffman, uncovered correspondence from a Dutch missionary, named Van Kessel, who claimed that warriors from the Asmat village of Otsjanep had killed and eaten Michael Rockefeller and taken his head in an act of revenge.
The reason? A few years before Michael’s arrival, a party led by a Dutch official set out to discipline the Asmat and discourage headhunting. In the confrontation that ensued, several high-ranking Otsjanep villagers were shot and killed. These deaths demanded revenge, and Michael Rockefeller – Hoffman argues – was killed in retribution as was required by Asmat culture.
It is perhaps worth noting that the Asmat had never been known previously to take the life of a white man.
Van Kessel’s superiors dismissed his account and summoned him back to the Netherlands. At the time, the Dutch were ceding control of what was then Netherlands New Guinea to Indonesia, and did not want any troubling and inconvenient facts coming to light at a sensitive time.
Continued attempts at dispensing modern-day justice to primitive cannibals may well have been deemed too challenging; also the sensibilities of the Rockefeller family were taken into account. So the truth about Michael Rockefeller’s grisly end was ‘hushed up’. That is Hoffman’s conclusion, based on his researches.
At the end of the book, Hoffman describes how he returned to the Asmat region, making contact with descendants of Michael’s presumed killers, in the hope of getting some kind of confession. But he met with no cooperation and left, sensing that the villagers were still guarding a secret that they wanted to remain buried.
A short article summarising the Rockefeller story can be found here.
References Carl Hoffman Savage Harvest: A Tale of Cannibals, Colonialism, and Michael Rockefeller’s Tragic Quest for Primitive Art, William Morrow/HarperCollins Publishers, 2014.
© Dr Richard Thomas