Lately I’ve been thinking and giving some talks about Scandinavian pseudoarchaeological writers, that is, people who publish books on the past with unsubstantiated claims to scientific credibility. The beyond all comparison most famous of them is the Norwegian Thor Heyerdahl (1914-2002).
Heyerdahl is mostly known not as an archaeologist, but as a great navigator, being the organiser of numerous projects where he would have a reconstruction built of some ancient boat and make an ocean voyage with it. Most famously, he travelled by balsa raft from Peru westwards to Tuamotu in 1947 (with my countryman Bengt Danielsson on board). What may not be apparent to everyone is that almost everything Heyerdahl did throughout his professional life was motivated by one overarching archaeological hypothesis: hyperdiffusionism.
Diffusionism is the view that ideas (such as tech inventions) travel. If I invent something good or interesting, then people who see it may pick up the idea and run with it, and the idea will propagate across the world like rings on a pond do when you drop a prosthetic silver nose into it. Ideas will diffuse like drops of watercolour in a glass of water. It is generally accepted among scholars that this does happen to some extent in real cultures, with the important caveats that sometimes inventors will try to keep their ideas from propagating, and in many cases potential receivers will refuse to pick up certain ideas. An important example of the latter is what happened to the diffusion of agriculture when it reached northern Germany. The Linearbandkeramik culture had agriculture, and their Ertebölle culture neighbours to the north were well aware of it, but they refused to copy it for a thousand years. They were happy to continue with their fishing and oyster-collecting Mesolithic lifestyle despite having an alternative. Apparently, people in the past did not always feel that steps that led in the direction of modern civilisation were very attractive.
Another important argument against diffusionism as a wholesale explanatory model is that if one group can invent agriculture / pottery / pyramids / irrigation / writing / metalworking, then clearly it wouldn’t be too hard for a similar group somewhere else to make the same inventions on their own. This has been proved to have happened, for instance with agriculture in the Americas, where the cultivated crops are completely different from the ones in the Old World. Biologists will recognise this as convergent evolution: every marine top predator throughout geological history ends up looking pretty much the same regardless of its ancestry, simply because of hydrodynamics.
Thor Heyerdahl could not accept the idea of independent inventions, of convergent cultural evolution. His thinking wasn’t just diffusionistic on the small-to-middle scale. Every one of his boat trips revolved around hyperdiffusionism, being designed to show that it was possible, more specifically regarding the package of ideas that we call state civilisation. And that’s where he went wrong. Instead of searching for evidence that diffusion had taken place (e.g. Egyptian pottery in Mexico), he spent his life “testing” whether the needed sea travel could have taken place in antiquity. This is still apparent even in his last book, “The Hunt for Odin”, where he goes back to some euhemeristic ideas of Snorri Sturluson and argues that a real person named Odin brought civilisation to Scandinavia from the Middle East.
Thor Heyerdahl’s forays into archaeology were pseudoscience because he had a single favourite model that he refused to let go of. But he also displayed another typical trait among pseudoarchaeologists: hostility against mainstream academia. With Heyerdahl, we are looking at a man with a great many honorary doctorates, but no university degree. He was unwilling to work within the confines of science with its peer review, its debates and its career structure, and he got a lot done beyond that world. But while many Norwegians celebrate him as a national hero and a conqueror of the seas, one whose memorial museum is (tellingly) located a stone’s throw from the Viking Ship Hall in Oslo, scientific archaeology and ethnography and biology have all but forgotten him.