Which of your two cultures were the ones who cut peoples' living hearts from their bodies and drank their blood? Men, women and children? 
I keep getting the Inca and Maya confused. 
Ah, here it is! They both practiced human sacrifice!
Go to Chichen Itza and look at the bones of their victims. 
http://mayaincaaztec.com/mateofhusa.html
This is your 'advanced' culture, right?

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