Final answer:
The movement toward greater social stratification in human societies was inspired by factors such as increasing social stratification and labor specialization.
Step-by-step explanation:
The movement toward greater social stratification in human societies was inspired by several factors, according to Harris (Life without Chiefs). One of the more general pressures was increasing social stratification, which refers to the division of society into different social classes or levels. This division allowed for the emergence of elites who acquired wealth and power, becoming leaders with the authority to command armies and create rules for society. Another factor that contributed to social stratification was the need for labor specialization, where individuals could specialize in skills other than food production, such as trading or religious leadership. These individuals often acquired wealth and higher social status, furthering the social divisions.