Before revision: Many societies are horizontal and maintained an egalitarian way of life, such as the Jola or Hadza peoples, while others did not centralise further into complex societies, such as the Boorana and the chiefdoms of Sierra Leone, and are rarely discussed in political history.
After revision: Many societies are horizontal and maintained an egalitarian way of life, such as the Jola or Hadza peoples, while others did not centralise their proto-states further and stratify into complex societies, such as the Boorana and the chiefdoms of Sierra Leone, and are rarely discussed in political history.