Compare the aztec and inca societies with those of the pacific islands. what were the similarities? what were the significant differences?

I know for sure that the Aztec and Inca societies would practice human/animal sacrifice in order to have a "sun rise;" sacrifice it to the Gods up above. I also know that the Aztec and Inca societies were really behind when it came down to centralized government trade. 
That's all I know and hope this helps!