The Ecological-Evolutionary Typology of Human Societies and the Evolution of Social Inequality

2.3Sociocultural Evolution and Social Inequality

2.3.1Sociocultural Evolution

In Figure 2.1 arrows show documented transitions between different types of societies. Lenski's view of sociocultural evolution is not a naïve one of "progress". In fact, in his view, sociocultural evolution takes place through two main mechanisms:

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  intrasocietal selection: the process in which a new cultural element is adopted, or an old one discarded, within a single society; an example is the disappearance of slide-rules, replaced by electronic calculators
  
• 
  intersocietal selection: the process in which an entire sociocultural system is destroyed following contact with another (usually more powerful) society, with or without the physical destruction of the members of the losing society; an example is the disappearance of many native American societies following expansion of Europeans into the Western frontier
  

Lenski's discussion suggests that intersocietal selection is the predominant engine of evolution (see discussion of the Great Paradox in Nolan and Lenski 1999). Thus most societies that have existed have not themselves evolved, but have at some point been destroyed or absorbed by societies of a more advanced type. Moreover, evolution does not consist of the wholesale transformation of a former type into an advanced one during a short period of time, but rather of the progressive increase in the frequency of a given type among all human societies (and the percentage of the world population living in that given type). Lenski's mental image of the succession of societal types was originally similar to that of the succession of dominant species in the course of biological evolution, each with a cycle of expansion, dominance and extinction; this was later replaced by the picture shown in recent editions of Human Societies (Nolan and Lenski 1999:75, Figure 4.2).

2.3.2Evolution of Social Inequality

Much of Lenski's macrosociological work is devoted to understand the evolution of social inequality within his general perspective on sociocultural evolution. The major premise is that a given type of society will generate a specific type of stratification system characterized by a given degree of inequality. Lenski has summarized his view of the evolution of social inequality in the graph shown in Figure 2.2, depicting the trajectory of the "freedom" enjoyed by the member of the elite and the average member of society in the course of sociocultural evolution.
------ Figure 2.2 about here ------
Figure 2.2 shows how freedom for the average member of society declines monotonically from the hunting and gathering to the agrarian stage, to improve later in the course of industrialization. The theoretical reasons behind this postulated trend are twofold (Lenski 1966:89, Figure 2):

1. 
   In part the evolution of inequality traces the rise in the surplus made available by a given subsistence technology; thus for part of sociocultural evolution, increasing productivity of labor has entailed increasing surplus, which has been appropriated by the elite and concentrated into their hands in increasingly disproportionate amounts.
   
2. 
   Another part of the evolution of inequality is related to specific constraints or requirements of a given technology, which may directly affect "basic demographic, political, and productive patterns of organization" (Lenski 1966:89, Figure 2); for example, in herding societies the herds are vulnerable to theft, and this puts a premium on military might, which in turn may amplify hierarchical tendencies in those societies; likewise, maritime societies may not have as much inequality as their surplus would predict, because they tend to generate a powerful class of merchants with an affinity for republican forms of government.
   

Figure 2.2 focuses on the "main sequence" of sociocultural evolution (excluding specialized societies). The nadir of freedom for the average member of society is shown to correspond to the agrarian stage. I will argue later that the notions of freedom (or "human rights") and inequality (in the sense of a skewed distribution of resources, as measured e.g. by the Gini coefficient) do not necessarily coincide, and that while inequality in a distributional sense may be very high in the late agrarian era, the nadir in freedom (i.e., human rights) terms may correspond to the earlier, advanced horticultural stage.

2.4Empirical Implementation of the Ecological-Evolutional Typology

2.4.1Comparative Data Sets

The most comprehensive resources for testing cross-cultural comparative hypotheses are the Ethnographic Atlas, a data set with quantitative data on 1267 societies originally published by George P. Murdock (1967), and the Standard Cross-Cultural Sample, a subset of 186 societies considered "representative" of the universe of human societies selected later by Murdock and White (1969). The data as well as supporting materials (codebooks and bibliography) are currently distributed by the electronic journal World Cultures (see web site at

http://eclectic.ss.uci.edu/~drwhite/worldcul/world.htm). From the first editions of Human Societies Lenski used tables and graphs from these sources. In the following I will refer to the Ethnographic Atlas and the Standard Cross-Cultural Sample as EA and SS, respectively. I will use EA and SS to relate the ecological-evolutionary typology to dimensions of social inequality.

2.4.2Identifying Types of Societies in EA and SS

One can identify the type of society corresponding to the ecological-evolutionary typology from information contained in EA and SS:

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  Percentage dependence for subsistence on gathering, hunting, fishing, animal husbandry, and agriculture (meant as any type of farming)
  
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  Use of plow animals (taken as indicator of the use of the plow for farming)
  
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  Presence of metal working
  

Using these variables one can first classify societies according to the principal subsistence activity into Hunting and Gathering, Fishing, and Herding societies, and societies dependent mainly on farming. Then among farming-dependent societies one can use the plow to distinguish between Agrarian (plow present) and Horticultural (plow absent) societies. Then the presence of metal working allows distinguishing between Simple Horticultural and Advanced Horticultural societies. The Appendix shows the procedure used to classify the societies in the form of computer pseudo-code to facilitate replication of the analysis by others. There are no societies of the industrial type in the EA or SS, and Maritime societies cannot be distinguished since subsistence is recorded in terms of food production, not money obtained through commercial activities. So we can distinguish the following type of societies, for which I will use from now on the simplified two-letters code:

HG – Hunting and gathering

SH – Simple horticultural

AH – Advanced horticultural

AG – Agrarian

FI – Fishing

HE – Herding