From Scienceblogs:

Lately I've been thinking and giving some talks about Scandinavian pseudo-archaeological 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.   Thor Heyerdahl's forays into archeology were pseudoscience because he had a single favorite model that he refused to let go of.

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.