Final answer:
Social control in a tribe (decentralized) society is primarily based on informal norms and small group cohesion.
Step-by-step explanation:
The type of society in which social control is primarily based on informal norms and small group cohesion is a tribe (decentralized). In tribal societies, extended families or councils play a role in organizing leadership, decision-making, and conflict resolution. These societies often rely on subsistence modes such as pastoralism and horticulture, and they can range in size from a few hundred to several thousand people.