Aku-Aku, the Secret of Easter Island is a 1958 book by Thor Heyerdahl that described his research at Rano Raraku and Anakena on the many giant stone statues or moai found on Easter Island and the culture that created them.
The book and a follow-up film of the same name made a major contribution to general public awareness of both the island and the statues, outside the anthropological and archaeological communities.[1] Much of Heyerdahl's evidence has now been refuted by archaeologists, and his methods have been heavily criticised. For example: Paul Bahn wrote: "he relied on the selective use of evidence, which resulted in a misleading conclusion".[2]
Heyerdahl is most controversially associated with an attempt to revive the theory that the islanders stone-carving technology came from South America. He argued that in addition to having been settled by Polynesians, Easter Island was settled by people from Peru in South America (an area he described as being "more culturally developed").[3]
"Aku-aku" can refer to moving a tall, flat-bottomed object (such as a bookshelf) by swiveling it alternatively on its corners in a "walking" fashion. Heyerdahl theorised that the moai (statues) of Easter Island were moved in this fashion. He tested this theory on a small moai; however, he quickly abandoned the test after the moai's base was damaged.[4]
Heyerdahl further asserts that, for the islanders, Aku Aku also means a personal spiritual guide. Near the end of the book, Heyerdahl elucidates on a conversation with his own aku-aku.
Heyerdahl compared the highest-quality stonework on the island to pre-Columbian Amerindian stonework, such as at Tihuanaco. Seemingly unaware of Polynesian stoneworking traditions, such as the Marae, he said of Ahu Vinapu's retaining wall, "No Polynesian fisherman would have been capable of conceiving, much less building such a wall".[5] But, researcher Alfred Metraux had already pointed out[6] that the rubble-filled Rapanui walls were a fundamentally different design from those of the Inca.
Heyerdahl claimed a South American origin for a number of Easter Island plants, including the Totora reeds in the island's three crater lakes. These are now recognised as a separate species from similar ones in Lake Titicaca. He made the same claim for sweet potato. Scientists now believe that it was cultivated in Polynesia before Easter Island was settled, and taken there by Polynesians.