A multitrajectory, competition model of emergent complexity in human social organization

Abstract

The repeated pattern of emergent human organization at a societal level going from small-scale, egalitarian decentralized societies to complex, stratified, and centralized societies is well-documented in the archaeological record of past societies. In this paper, I outline a multitrajectory model that relates to the broad features of this sequence of societal change. Competition is shown to play a critical role in the way interaction-among decision making, demographic parameters, and social units that organize resource ownership and procurement-either promotes or inhibits change in social organization. Multiagent simulation is discussed as a way to link culturally embedded decision making to emergent properties in the multitrajectory model.

Emergent Properties in Small-Scale Societies

“…As shown in Figure 2, birth spacing is almost always 3 years or longer in the simulation, which compares well with the observation that common values for birth spacing among the !Kung san are 3 and 4 years and birth spacing is seldom less than 3 years [10, p. 145]. In contrast, the logistic model has a different pattern with birth spacing of 2 years occurring frequently (see [20,Figure 9]). Three runs with approximately the same stabilized population size but different parameter values for Wt are shown in Figure 3 parenting cost is a relatively robust solution.…”

“…The fact that camp exogamy emerges as a macro-level property from micro-level, kin-based incest rules may explain a fact not discussed here: that the !Kung san do not have any cultural restriction on marrying within one's living group despite the fact that a cultural rule of exogamy with respect to one's social group often occurs in small-scale societies (see [20] for a more extended discussion of camp exogamy arising as an emergent property). Marriages between families in different camps are important for a group such as the !Kung san, as these marriages provide a way for individual families to have access to resources in localities other than their own through kin relations created through marriages with families in other localities.…”

“…In the residence-camp exogamy simulation discussed below, where exogamy refers to marriages outside one's camp, a cultural rule for contracting marriages is used as well. However, both versions lead to the same general pattern for the birth spacing simulation [20], and so marriage rules will be ignored in this simulation with its focus on birth spacing.…”

“…These assumptions have been implemented into a multi-agent demographic simulation, discussed more fully in Read [20], by having a female agent use a decision rule for birth spacing that takes into account both her current parenting costs and her current energy and time allocation for foraging activities. Major events of the simulation, based on a time period of one year for simulation events, are given in Table 1.…”

Simulating the effect of nepotism on political risk taking and social unrest

“…ABM simulations allow researchers to program theoretical processes, and test whether or not these processes lead to observed phenomena in the context of simulated social systems (Epstein and Axtell 1996). Anthropologists use ABM simulations to explain the rise and fall of civilizations (Axtell et al 2002, Dean et al 2000, Lazar and Reynolds 2002, to model the emergence of ethnic groups (McElreath, Boyd, and Richerson 2003) and cultural complexity (Read 2002), to study irrigation systems (Lansing and Miller 2005), to model the impacts of tourism on arctic communities (Berman et al 2004) and colonization on Amazonian ecosystems (Deadman et al 2004), and to explain the creolization of languages (Satterfield 2001). ABMs are also used to understand the emergence of social unrest, rebellion and terrorism (Kuznar, Sedlmeyer, and Frederick 2005, Lustick 2002, MacKerrow 2003, Srbljinovic et al 2003.…”