Dutch twins Adrie and Alfons Kennis are showing their uncanny models in museums all over Europe. Adrie discusses how their creations are realised and the extreme reactions they can provoke

Identical twins with a combined age of 102, Adrie and Alfons Kennis are among Europe’s most sought-after – and controversial – hominid palaeo-artists: sculptors of lifesize reconstructions of early humans.

Working from a studio in their home town of Arnhem in the Netherlands, the brothers bring a surplus of exuberance to their creations, which are richly animated, expressive and – how better to put it? – human, even when they aren’t quite human. “If we have to make a reconstruction,” says Adrie, “we always want it to be a fascinating one, not some dull white dummy that’s just come out of the shower.”

In the 10 or so full-sized reconstructions completed during their career they have run the gamut of human history, from “Lucy” – the earliest known hominin fossil – to Homo erectus, Neanderthal man and, of course, Homo sapiens. Just last week, they put the finishing touches to a model for St Fagans National Museum of History in Wales. Due to be unveiled in October, it will be the third Kennis & Kennis work on display in the UK.

The process is exhausting. First, they rebuild the skeleton, sometimes using fossils from several different sites, with the help of computer scans and 3D printing. The skeleton is suspended with wire cables and the spine is made flexible using silicone cartilage between the vertebrae. “We use a kind of paraffin wax clay to sculpt the muscles,” says Adrie, “and we make arteries using small ropes which lie over the muscles.” Layers of another clay are then wrapped around the sculpture as skin, and a mould is made to replicate the sculpture in silicone. “We do five layers of silicone to make the skin colour,” explains Adrie, “because real skin is translucent.”

Facebook Twitter Pinterest The Kennis brothers at their studio in Arnhem, at work on a model of a Neanderthal woman for the National Geographic Society. Photograph: Alamy Stock Photo

To achieve the remarkable accuracy and individuality of each of their sculptures, the Kennis brothers draw deeply from two reservoirs of inspiration. First, they are students of the science behind human anatomy and evolution, constantly educating themselves about the relative merits of the human and Neanderthal pelvis, and painstakingly rebuilding skeletons and musculature for each new sculpture. Fortunately for them, their career has coincided with huge leaps in DNA testing, allowing them to accurately recreate genetic traits such as hair type and eye colour. (Earlier this year, a heated political debate broke out after a Kennis model portrayed the earliest Briton, known as Cheddar Man, with dark skin.)

Second, they are keen amateur anthropologists, and their sculptures are influenced as much by modern tribal peoples as they are by the fossilised skulls of their actual subjects. By studying people from more isolated or primitive societies, the brothers believe they can see through a window into the past. “They live outdoors, with completely different rules from ours. If you see pictures of the Tehuelche people of Patagonia, they walk nearly naked in snow. They have totally adapted to those conditions. And if you imagine going much further back in time, imagine how different those people would be…” For this reason, Kennis models often exhibit unique hairstyles and tribal tattoos, and strike poses that appear startlingly modern, provoking strong reactions. “We bring it to the museum, and many times the museum directors are shocked, because they find it too extreme, too alien.”

This alien-ness is tempered, however, by their particular skill for facial expressions, giving life and personality to the clay. Each full-sized reconstruction takes half a year, but a face alone can take a whole month, and although the brothers refuse to refer to themselves as artists, this is obviously the area that gives them the greatest artistic freedom and satisfaction. “There are some things the skull can’t tell you,” admits Adrie. “You never know how much fat someone had around their eyes, or the thickness of the lips, or the exact position and shape of the nostrils.”

This personal quality is what makes Kennis models so captivating, and so desirable to museums: they don’t simply depict a generalised early man, but a specific man or woman, an effect that allows onlookers to glimpse human prehistory with immediacy, even familiarity. But while curators and museum-goers are sometimes surprised by the vivid, emotive features of the Kennis models, there is only one person Adrie needs to impress: “If Alfons doesn’t like the face, I am disappointed. But if he likes it, if we are both satisfied, then we can handle the whole world.”

Homo sapiens and Neanderthal side by side (pictured at top of article)

Natural History Museum, London

These two reconstructions demonstrate the differences between an early human – in this case taken from a Czech fossil – and his distant relative the Neanderthal, reconstructed from Belgian remains. “We made them as a pair, to compare,” says Kennis. “That’s why they are in a relaxed pose, never a cliched hunting or making-fire pose, because then you can’t see the anatomical differences between them.”

For the same reasons, the models are unclothed. “We like to keep them naked because then you can see the features clearly: the Neanderthals were short with big hands and a broad pelvis, the first Homo sapiens were very slender.” This has been another source of controversy in the brothers’ work. “Chris Stringer, the head of anthropology at the NHM, gets emails all the time, usually from fathers, saying it’s scandalous that his daughter had to see a naked guy in the museum. It’s always parents that make the problems

Facebook Twitter Pinterest The reconstructed face of Cheddar Man at the Natural History Museum: ‘Many people were surprised by his dark skin.’ Photograph: Natural History Museum London/EPA

Cheddar Man

Natural History Museum, London, United Kingdom

“Cheddar Man”, Britain’s oldest complete skeleton, was a mesolithic hunter-gatherer living around 10,000 years ago. Kennis and Kennis made the reconstructed head for a Channel 4 documentary earlier this year, using the skull found in Cheddar Gorge in 1903. Contrary to previous assumptions, DNA analysis revealed that Cheddar Man had dark skin and wavy hair, and the model was met with some controversy. “Many people were surprised by his dark skin,” says Kennis, “but for us, it was not a big surprise. At least three other hunter-gatherer skeletons have been found in Europe from around the same time, and DNA tests show they all have that strange combination of dark skin and blue eyes.”

Facebook Twitter Pinterest Neanderthal woman and child: ‘The Neanderthal sense of community was not so different from ours.’ Photograph: Kennis & Kennis Reconstructions

Neanderthal woman and child

Gibraltar Museum

This pair of Neanderthals, commissioned by the Gibraltar Museum in 2016, display the Kennises’ commitment to marrying scientific accuracy with human characteristics. “When we put the skeletons together,” recalls Adrie, “we used two life models standing for us. The child model happened to put her arms around her grandmother, and the grandmother’s face was suddenly so proud – proud of her granddaughter. It was such a nice idea, the woman looking proud while the child hangs around her waist.”

Not much is known about the Neanderthal sense of community, but Kennis imagines a civilised species: “Neanderthals were quite modern. In la Sima de las Las Palomas [a Neanderthal cave in southern Spain] they were found buried, aligned together, with a panther claw on their chests. They had some art, they had bigger brains than us; I think the Neanderthal community was not so different from [that of] Homo sapiens.”

Facebook Twitter Pinterest Early European man: his DNA is 9% Neanderthal. Photograph: Kennis & Kennis Reconstructions

Early European man from Peştera cu Oase, Romania

Neanderthal Museum, Mettmann, Germany

“This is the first western European Homo sapiens,” says Kennis, “reconstructed from the skull of a young adult, about 34,000 years old.” At this point in prehistory, humans had migrated to Europe from Africa via the Middle East, and Neanderthals had only recently become extinct. “Modern humans [those who left Africa around 70,000 years ago] have up to 4% Neanderthal DNA, but this man has about 9%. His ancestors had bred with Neanderthals only six generations before.”

As is often the case with Kennis & Kennis, the sculpture has raised curious questions about race. “If you ask people to pinpoint what continent he comes from, people say such different things,” says Kennis. “But he actually comes from Romania.”

Facebook Twitter Pinterest Tarzan he isn’t: Adrie and Alfons Kennis with their model of Ötzi the iceman. Photograph: AFP/Getty Images

Ötzi the iceman

South Tyrol Museum of Archaeology, Bolzano, Italy, 2011

More recent than most of Kennis & Kennis’s subjects, Ötzi lived in the Tyrolese mountains 5-6,000 years ago, during the copper age. Because his body was mummified in ice, much more can be deciphered about his physiognomy and lifestyle. “He was 45, which is quite old,” says Adrie, “and he was very sick when he died, with stomach problems. His skull has an underbite, and his face points downwards: not a pretty face. Some people who see the reconstruction say: ‘Wow! It’s good!’ because he looks like shepherds who live high in the mountains and spend their lives out of doors.”

Not everyone, however, was so thrilled with the Kennis version of Ötzi. “We did some research around the village where he was found, and many people thought he was young and handsome – a Johnny Weissmuller kind of guy. You should have seen how disappointed they were when they saw our reconstruction.”