Another general principle of grouping is that of propinquity and contiguity. The essence of social life is coöperation. People can only exchange services, work together, and rely on supplementing each other as regards task and ability, when they are within reach. And conversely, people who are close neighbors must come to some agreement on a whole number of points. They must delimit their rights of residence, their use of objects of general interest and utility. They have sometimes to act conjointly when some danger, calamity, or pressing business calls them to action. Obviously the smallest neighborhood group is the household, so that this series starts with the same institution as the one described above. Yet invariably we have also some forms of organization which embrace a number of families and other kinship units. The local group may consist of a nomadic horde, a sedentary village, a little municipality or township, or be simply the organization of scattered hamlets or homesteads. Since there are, however, as pointed out above, definite advantages in organization, while lack of organization is impossible, because it would leave a whole set of burning questions unsolved, it is always possible to determine the institution which we might call municipality in the widest sense of the term, or the local group. The principle of propinquity, like that of kinship, can be extended several removes. Here a much greater latitude prevails, and according to the situation, we might speak of areas, districts, provinces, all or one of them, always bearing in mind that we can list them as institutions only insofar as they are definitely organized. The widest such territorial unit of potential coöperation, exchange of services, and community of interest would be the tribe, in the cultural sense of the term.
Bronisław Malinowski, A scientific theory of culture (Chapel Hill: University of North Carolina Press, 1944 ), pp. 56–57.