Kinship-based politics and the optimal size of kin groups

Abstract

Kin form important political groups, which change in size and relative inequality with demographic shifts. Increases in the rate of population growth increase the size of kin groups but decrease their inequality and vice versa. The optimal size of kin groups may be evaluated from the marginal political product (MPP) of their members. Culture and institutions affect levels and shapes of MPP. Different optimal group sizes, from different perspectives, can be suggested for any MPP schedule. The relative dominance of competing groups is determined by their MPP schedules. Groups driven to extremes of sustainability may react in Malthusian fashion, including fission and fusion, or in Boserupian fashion, altering social technology to accommodate changes in size. The spectrum of alternatives for actors and groups, shaped by existing institutions and natural and cultural selection, is very broad. Nevertheless, selection may result in survival of particular kinds of political structures.demography ͉ selection D emographic fluctuations affect the composition of kin groups (1). Positive shocks increase numbers of kin per person but decrease inequality of kin distributions and vice versa. Kin are the main source of political support and action in the small societies that characterized Ͼ90% of human history and still predominate in many societies, including segments of larger societies. Fluctuations in the mean supply of kin and the inequality of kin distributions give political actors opportunity to consolidate their positions and to select or alter cultural institutions that give advantage. Demographically induced fluctuations in kinship distributions may have been important environmental factors in natural and institutional selection as well as in particular historical events. However, any intrinsic directionality in selection is subject to existing local institutional and environmental factors.This article presents a formal model of kinship factors, first focusing on a microeconomic analog, and then taking a broader macroeconomic and ecological perspective. It then discusses some ethnographic examples and offers conjectures on implications for the development of political institutions. A Formal Model of Kinship PoliticsEach political actor is a member of a kin group. Each kin group can have from zero to some number of additional persons. Any member can be thought of as the principal actor in the group, or the group can be thought of as an entity. Each group is, in principle, nested, with superordinate levels at greater collaterality. The model is unilineal, agnatic, and segmentary. † Thus, a set of agnatic male second cousins may consist of more than one set of agnatic male first cousins, which may consist of more than one set of brothers. At any level, groups are assumed to be mutually exclusive; for example, Ego cannot belong to more than one set of agnatically related brothers. At any level, groups may compete for dominance, regardless of whether they are subsumed under a broader group; for example, two sets of brother...

An application of the variable-r method to subpopulation growth rates in a 19th century agricultural population

“…For farming households to remain sustainable, they must walk a tight demographic line between persistence and failure. This suggests, at least for smallholder agriculture (Netting 1993), that individual families must balance their current and future economic interests by managing fertility and the household consumer/worker ratio, while ensuring an adequate labor supply (Chayanov 1966;Durrenberger 1984;Durrenberger and Tannenbaum 2002;Hammel 2005aHammel , 2005bHammel , 2005cVan Bavel 2004). This assumes that the family provides much of the household's agricultural labor, an assumption which generally holds for smallholder agriculture, and is especially true in the current setting of the northern islands of Scotland.…”

How Crow-Omaha Skewing Spreads

“…But their coordinated skewing and marriage rules allowed extension of alliances beyond their borders, diminishing competition. In a related vein, Hammel (2005) frames the effects of demographic stress/increase on kinship systems as both Malthusian, leading to group fission and "emigration out of a common ecological zone," and Boserupian, where "the group may move upward technologically . .…”

Infrastructure and the Energy Use of Human Polities

“…Here, by governance systems we mean the interlocking sets of formal and informal norms and rules that limit conflict and structure the scale and stability of collective action in social groups (North et al, 2009), and by norms and rules we mean the socially learned information shared between a group of peers and/or across generations, that shapes the opportunity costs of social interactions (e.g., North, 1990;Richerson & Boyd, 1998). Long-standing arguments in the social sciences posit that variation in how human groups construct their governance systems impacts, via a positive feedback process, the performance of human economies (e.g., Fukuyama, 2014;Hammel, 2005;Henrich, 2020;North et al, 2009;Putnam et al, 1993). If correct, then variation in governance systems should modify human behavior in ways that modify the basic scaling of population and energy use in human societies.…”

“…More intensive kinship describes governance systems in which relatives form tight, reciprocal relationships that favor high in-group trust, collectivism, and cross-cousin marriages as patriarchs consolidate control over resources and mobilize defense against other such kin groups (Henrich, 2020; Murdock, 1967). For example, speaking of extreme cases, Hammel states “The politics of African, Near Eastern, and Central Asian segmentary societies may often be understood by the repeatedly cited [Bedouin] proverb: Myself [stands] against my brother, my brother and I [stand] against my cousin, my cousin and I [stand] against the stranger.” (Hammel, 2005, 11,954). More extensive kinship, conversely, describes a situation in which individuals increase the size of their social-networks via generalized norms that emphasize forming bonds outside of blood kin, leading to socialization pressures that emphasize more trust of strangers, reciprocity/reputation effects with non-kin, and voluntary associations (Henrich, 2020; Hill et al, 2014; Ostrom, 1998).…”