comparing the Inca,Aztec,and Maya civilzations

The Incas and the Maya's social system were very similiar.For example they only had two social classes while the Aztec's had four.And also there social classes were all organized by the highest power to the lowest power.There social classes were treated diiferently espically the lower classes becuase they had the least power.Its very important for these three civilzations to have social systems because with out them there society would of been out of control and they probaly would of lost power easily.And there empire would of ended earlier.