||5. Type of Warfare Determines Marital Residency||Page 6|
The existence and type of warfare, in turn, may be causally linked to population density and size. Low density is associated with low frequency of warfare, while greater density is) associated with higher frequencies of warfare. Small populations are associated with external warfare and large populations with internal warfare.
With low population density, there is a smaller probability of contact between communities, from which one would expect a lower frequency of warfare. In fact, within the present sample of cultures, 27 of the 32 cultures with low frequencies of warfare had populations under 21,000. This can help explain why it has been found that lack of strict marital residency rules is a consequence of depopulation (Ember , 1975 Ember and Ember, 1972). Depopulation would be expected to decrease inter-community contact which would decrease the likelihood of warfare which would, in turn, be reflected in a relaxation of marital residency rules. Lowered rates of warfare under conditions of depopulation may explain the well-publicized lack of war among contemporary Kung bushmen who have lost the free-ranging life style of a century ago when warfare apparently existed (Lee, 1979, p. 382), among Mbuti pygmies whose groups seldom see each other in recent time., and "so long as we not meet there is no fighting" (Turnbull, 196] , p. 275), and among Eskimo or Lapp communities that are often located at remote distances from each other .
The type of warfare may be related to population size. As pointed out by Carol Ember (1974) larger populations usually provide the setting for internal warfare. The relationship holds true in the present sample as shown in Table 6: of 29 cultures with populations over 21,000, 22 had internal war, while of 86 cultures with smaller populations only 36 had internal warfare. This is significant by Chi square = 8.7, probability less than .01. Ember explained this relation by pointing out that cultures with large populations have more geographical spread and therefore they may find it more difficult to maintain cohesion and avoid internal war. This might be expected especially in stateless cultures such as those under investigation in the present study. As for external warfare, it usually occurs in cultures with small populations, according to Ember, a relationship that also holds true in the present sample: of the 25 cultures with exclusive external war, 23 had populations under 21,000.