Robert carneiro's theory of environmental circumscription holds that

Robert Carneiro’s theory holds why complex societies stimulated and no single factors explains the rise of all early complex societies. Multi casual can be made up of environmental circumscription, population pressure, warfare when operating together will managed to the rise of state. Written records can deliver clues but are not found in all early complex societies and it was unstable, periods of political unity spread out with those lacking political integration and this can complicate our understanding of complex societies.