Final answer:
Tribal societies are the type of sociopolitical systems featuring inequality but lacking socioeconomic stratification and stratum endogamy, unlike more stratified state societies.
Step-by-step explanation:
Among the different types of sociopolitical systems, tribal societies lack socioeconomic stratification and stratum endogamy although they do exhibit inequality and a permanent political structure. These societies are typically larger than bands and they rely on extended family structures and/or councils for leadership, decision-making, and conflict resolution. Sociologist Elman Service described tribal societies as associated with pastoralism and horticulture, where extended families have control over certain resources.
While tribal societies exhibit some degree of inequality, they do not have the rigid stratification seen in other systems such as caste or class systems. Conversely, state societies represent highly stratified multiethnic societies with centralized leadership and clear hierarchies of wealth and power. Systems like these reflect the accumulation of decisions and historical forces, creating complex social hierarchies and inequalities.