How are people in the community interdependent in the book The Giver?

In Jonas's highly structured, organized community, the Committee of Elders make every significant decision regarding how society functions by regulating the citizens' relationships, occupations, and family structure. In Jonas's society, each citizen is given a specific occupation that they must excel at in order for the community to function smoothly. From birth, the citizens are taught to rely on their neighbors and children must wear jackets with buttons in the back to nurture interdependence until they turn eight years old. In a society where individualism does not exist, the citizens view themselves as simply a part of the greater community.
The Speaker makes sure that each citizen is obeying the laws of the community and the Committee of Elders assigns all twelve-year-old children occupations. The highly organized, austere society is relatively small in order to avoid overpopulation and requires that each citizen contribute in some way, shape, or form to the community. If a citizen does not excel at their assignment or breaks the rules three times, they risk being released from the community.