Final answer:
Extended households are commonly found in agricultural societies, where collective labor contributes to farming and maintenance of the homestead, enhancing the social and economic stability of the community.
Step-by-step explanation:
Large extended households are most prevalent in the mode of livelihood known as agricultural societies. The extended family structure is closely associated with agriculture, where a high value is placed on labor and self-subsistence. This type of family unit includes multiple generations or married siblings living together, providing a robust social and economic support system that contributes to farming activities and the maintenance of the household.
In agricultural societies, each family member can contribute to the various tasks required, from planting and harvesting to caring for domestic animals, thus facilitating the production of food and other essentials. Extended households rely on the collective effort of its members, which in turn supports the social and economic stability of these agricultural communities.