Since mankind appeared on the earth, he has separated himself from the other animals through the use of his highly developed brain. At first he had to compete with other hominids for supremacy, but by the end of the Paleolithic Era the competition was eliminated and Homo Sapiens stood as the sole surviving Human species.
During the Neolithic Period, man became a farmer and gave up the life of a nomad. He developed tools and lived in tribes of 150-2000. There was no real social or economic stratification in those primitive clans, although the accumulation of herds led to differences in wealth. At the dawn of the Bronze Age, man began to live in larger groups. Villages were formed and social stratification began. With stratification came repression.