As another example, Alaska’s Iñupiat (Plate 9) consist of 10 groups with mutually exclusive territories. People from one territory caught trespassing on another territory were routinely killed, unless they proved to be related to the territory-owners who caught them trespassing. The two commonest causes of trespass were hunters crossing a boundary in hot pursuit of reindeer, and seal hunters hunting on an ice shelf that broke off and drifted away from land. In the latter case, if the ice subsequently drifted back to shore and the hunters found themselves landing in another territory, they were killed. To us non-Iñupiat, that seems cruelly unfair: those poor hunters were already taking a big risk to have gone out onto a floating ice shelf, they had the bad luck that their shelf broke off, they were then at risk of death from drowning or being carried out to sea, now they had the great good fortune to drift back to shore after all, they had no intentions of trespassing but were just carried innocently and passively by an ocean current—yet they were still killed just at the moment of their salvation from drowning or drifting to sea. But those were the rules of Iñupiaq life. Nevertheless, Iñupiaq territorial exclusivity wasn’t complete: outsiders occasionally were given permission to visit one’s territory for a specific purpose such as a summer trade fair, or to transit one’s territory for another specific purpose such as visiting or raiding a distant group living beyond the farther side of the transited territory.
When we collect the examples of societies (like my mountain friends, the Dani, and the Iñupiat) lying towards that extreme of mutually exclusive defended territories, we discover that that outcome arises under a combination of four conditions. First, defended territories require a population sufficiently large and dense that some people can be spared to devote time specifically to patrolling boundaries, so that the population doesn’t have to rely just on everyone casually keeping out an eye for trespassers while in the course of normal foraging. Second, exclusive territories require a productive, stable, predictable environment within which the territory-owners can count on usually finding most or all of their necessary resources, such that they rarely or never need to go outside their territory. Third, the territory must contain some valuable fixed resources or capital improvements worth defending and dying for, such as productive gardens, groves of fruit trees, or fishing weirs or irrigation ditches requiring much effort to build and maintain. Finally, group membership must be rather constant, and neighboring groups must be largely distinct, with little migration between groups—the main exception being movements of unmarried young people (more often women than men) leaving their natal group in order to marry into another group.
We can observe how those four conditions are satisfied by the groups I’ve just mentioned as approaching the extreme of exclusive territories and defended boundaries. My New Guinea mountain friends have a significant investment in their year-round gardens, pigs, and forests, which traditionally gave them everything that they needed. Clearing forests and developing gardens are laborious for them, and are even more so for western New Guinea’s Dani, who dig and maintain elaborate systems of ditches to irrigate and drain their gardens. The Iñupiat and Ainu occupy rich year-round territories with abundant marine resources of salt-water fish, seals, whales, and seabirds, fresh-water fisheries and waterfowl, and inland areas with terrestrial mammals to hunt. Arnhem Land’s Yolngu similarly lived in dense populations made possible by the combination of productive coastal and inland resources. Owens Valley’s Shoshone Indians were hunter-gatherers living at relatively high densities in an area with ample water that let them irrigate land to increase its yields of edible wild grass seeds, and that provided storable harvests of pine nuts. Those food stores, pine groves, and irrigation systems were worth defending, and there were enough Owens Valley Shoshones to defend them. Finally, Yanomamo Indians maintain plantations of peach palm and plantain trees that produce their staple foods for many years and are also worth defending.
In areas with especially large and dense populations, such as those of the Dani and the Sudan’s Nuer, not only are there separate groups each with its own territory, but those territorial groups are further organized into hierarchies of three or more levels. Those hierarchies remind us of the hierarchical organization of land, people, and political control familiar to us in our modern state societies, starting with individual house plots, and ranging up through cities, counties, and states to the national government. For instance, the Nuer (Plate 7), numbering 200,000 people in an area of 30,000 square miles, are divided into tribes of 7,000 to 42,000 people each, each tribe divided and subdivided into primary and secondary and tertiary subtribes, down to villages of 50 to 700 people and separated by 5 to 20 miles. The smaller and hierarchically lower the unit, the fewer are the disputes about boundaries and other matters, the stronger are the pressures that relatives and friends bring to bear on disputants to settle disputes quickly and without violence, and the more limited is any fighting that does occur. For instance, the Nuer observe few restrictions in their treatment of neighboring Dinka tribes: they regularly raid the Dinka, steal Dinka livestock, kill Dinka men, and take home some Dinka women and children as captives while killing the others. But Nuer hostilities against other Nuer tribes consist only of sporadic cattle raids, killing of just a few men, and no killing or kidnapping of women and children.
Non-exclusive land use
The opposite extreme of less or no exclusivity is approached under conditions that are the mirror image of the conditions selected for exclusivity. One such condition is sparse and small populations that make patrolling (other than casually looking for trespassers while out doing other things) impossible. For instance, a society consisting of just a single family can’t afford dedicated patrols, because it can’t have its single adult man spending all day seated at the top of a watch-tower. A second condition involves unproductive, marginal, variable environments with sparse and unpredictable resources, such that any territory one might feasibly claim would often (at some seasons or in a bad year) not contain essential resources, and one would then periodically have to seek resources in another group’s territory and vice versa. Third, it doesn’t pay to risk one’s life defending a territory containing nothing worth dying for: if one’s territory is attacked, it would then be preferable just to move to another area. Finally, territories are likely to be non-exclusive if group membership is fluid, and if group members often visit or transfer to other groups. It makes no sense to keep out another group if half of its members are visitors or transferees from your own group anyway.
However, the usual form of land division under these conditions selecting for non-exclusivity isn’t the extreme of a free-for-all in which anybody can do anything anywhere. Instead, it still is the case that each group is identified with a specific core area. Non-exclusive societies differ from exclusive societies in that, instead of the Dani no-man’s land clearly delineated by watch-towers, recognized borders don’t exist, and land ownership just becomes increasingly vague as one moves increasing distances from one’s core area. Another distinction of non-exclusive from exclusive societies is that neighboring groups receive permission to visit your territory more often and for more different purposes—especially to obtain food and water at certain seasons or in certain years. Correspondingly, you can readily obtain permission to visit your neighbor’s territory when you are the one in need, so the arrangement becomes an exchange based on reciprocity and mutual benefit.