One can imagine, that the Europeans got a strong cultural shock, when they first set foot on Mesoamerican soil in 15th and 16th century. Strange clothing, weird gods, odd architecture, different languages, just about everything was different. And those strange rituals, including ceremonial sacrifice of a living human. And cannibals everywhere.
Aztecs eating captives.
Maya eating children.
Men eating their family.
Women eating penises (which they made fall of by swelling, no less, according to Amerigo Vespucci)
How could such stories ever be told? How did they evolve?
The answer is a mixture of culture, politics and the weird human mind. When the Europeans started to the new worlds, there were stories. Think of ancient Greece, where they thought that, the farer you go away from Greece, the wilder the people are. Herodot told something about one-legged androphagoi (cannibals). Creatures, that have no head, but mouth, eyes and nose near the stomach. The Europeans expected to see cannibals – the topic was all over the place. And you see what you want to see.
At the time, the explorers started, stories about dog-headed creatures that ate humans were all around.
Marco Polo actually saw them – from a distance.
Christopher Columbus saw them – also from a distance. Shortly after he saw the Islands of the Amazons.
The expression “Cannibal” came from his reports, after a friendly tribe told him, that they are in fear of the “Caniba”, people on a neighbor island, that eat humans (just the island, where Columbus saw the one-eyed, dog-headed tribe).
The explorers brought their own cultural filter and experienced the expected. Even Christopher Columbus first interpreted bones in the houses of Indigenous cultures as what they were: ancestor worship. The next generation however did not. The explorer’s reports were bestsellers in Europe – everyone knew the scary stories about the cannibals. Then the Conquistadores and settlers came and indeed found cannibals. And more Cannibals. Suddenly everywhere have been Cannibals.
The Aztec were Cannibals, the Inca, the people living at the coast of Middle America. Everywhere they were!
At the time of the Conquista and many archeological records long time after, have been interpreted as proof for cannibalism. Which could also have been influenced by the decree of Isabella I. of 1503, which stated, that no Indigenous may be put to slavery, except cannibals. A cannibal was considered a wild and not a real human. We all know, what happened next.
Nowadays it looks different. Ethnologists suppose, that no single case of those accounts seems to be true. According to them it’s probable, that there has never been any methodical cannibalism in Mesoamerica, included ritual cannibalism. The suggesting pictures in the Codices should be interpreted as symbolic (bread and wine anyone?). The accounts of the Conquistadores could be strongly misleaded by their imagination.
(*) This time, it’s a real quote. He actually said that. And a lot more