THE ECOLOGICAL-EVOLUTIONARY TYPOLOGY OF HUMAN SOCIETIES AND THE EVOLUTION OF SOCIAL INEQUALITY*

François Nielsen
Department of Sociology
University of North Carolina
Chapel Hill

Running head: EVOLUTION OF SOCIAL INEQUALITY

To appear in Essays in Honor of Gerhard Lenski, special issue of Sociological Theory guest-edited by Bernice McNair Barnett.

Revised March 2003

*Address all correspondence to François Nielsen, Department of Sociology, University of North Carolina, Chapel Hill NC 27599-3210.  Phone 919-962-5064.  Fax 919-962-7568.  Email francois_nielsen@unc.edu.  Web site at www.unc.edu/~nielsen/.

THE ECOLOGICAL-EVOLUTIONARY TYPOLOGY OF HUMAN SOCIETIES AND THE EVOLUTION OF SOCIAL INEQUALITY
Abstract
Gerhard Lenski’s ecological-evolutionary typology of human societies, based on the level of technology of a society and the nature of its physical environment, is a powerful predictor of various dimensions of social inequality.  Analysis of comparative data shows that, while some dimensions of the stratification system (such as measures of social complexity) exhibit a monotonic trend of increasing inequality with level of technology from the hunting and gathering to the agrarian type, others (such as measures of freedom and sexual inequality among males) exhibit a pattern of “agrarian reversal” in which inequality increases from the hunting and gathering to the advanced horticultural type, but then declines with the agrarian type.  Theoretical and empirical implications of the agrarian reversal pattern for the study of social inequality are discussed.

ABOUT THE AUTHOR
François Nielsen is a native of Belgium.  He received his Ph.D. in Sociology from Stanford University and became a colleague of Gerhard Lenski when he joined the faculty at University of North Carolina in Chapel Hill in 1982.  At UNC he regularly teaches the introductory sociology course Human Societies, which was originally created by Lenski and was the inspiration for the textbook of the same title (now co-authored with Patrick Nolan).  His main research area is social stratification, particularly the causes of variation in inequality of the distribution of income among countries of the world and among counties of the United States.  He has published a number of articles on these topics in American Journal of Sociology and American Sociological Review.  He is also interested in the biological bases of social behavior. 

THE ECOLOGICAL-EVOLUTIONARY TYPOLOGY OF HUMAN SOCIETIES AND THE EVOLUTION OF SOCIAL INEQUALITY
In Power and Privilege (1966) and in eight successive editions of Human Societies (1970; Nolan and Lenski 1999) Gerhard Lenski proposed his influential ecological-evolutionary typology of human societies.  This paper investigates the usefulness of Lenski's typology in tracking the evolution of various dimensions of social inequality.  A number of themes are developed.
First, the ecological-evolutionary typology is truly exogenous, i.e., it is based on variables describing the infrastructure of a society (the level of technology and the nature of the physical environment), rather than on variables describing the superstructure (e.g., the type of political organization), as are the typologies of Service (1962, 1975) and Fried (1967).  Put another way, as Lenski (1994) emphasizes, his typology is constructed from independent variables and thereby differs from traditional typologies constructed from dependent variables; the ecological-evolutionary typology is inherently causal, rather than purely descriptive.
Second, as illustrated in Human Societies and further demonstrated in this paper, the ecological-evolutionary typology is a powerful empirical predictor of evolutionary patterns in a number of dimensions of social inequality (see also Heise, Lenski and Wardwell 1976).
Third, even though available comparative data sets measure a number of dimensions of stratification systems, it is surprisingly difficult to find a measure that represents a quantitative summary of the overall degree of inequality in access to resources, power, and privilege in a society.  One measure that comes close to that specification but has been overlooked in previous research is the degree of sexual and reproductive inequality among men, as it may be measured by the extent to which powerful men monopolize women as wives or concubines.  This aspect of inequality also constitutes a direct link between human social inequality and dominance hierarchies elsewhere in the animal world.
Fourth, clues from analyses of comparative cross-cultural data suggest that Lenski's depiction of the overall trend in social inequality over the main path of sociocultural evolution has to be qualified.  For some dimensions of social inequality the nadir of human freedom is associated with the advanced horticultural type of society, rather than with the advanced agrarian type as Lenski had conjectured.  The existence of such agrarian reversals in monotonic inequality trends has important empirical and theoretical implications for understanding the evolution of social inequality.

GERHARD LENSKI'S TYPOLOGY OF HUMAN SOCIETIES

Historical
The motivation for constructing the ecological-evolutionary typology of human societies is outlined in Power and Privilege (Lenski 1966:90-93).  In the earlier part of the work Lenski develops a general theory of stratification based on the premise that the level and mode of technology are a major influence on stratification systems.  Thus, he argues, to examine distributive systems across societies it is natural to use a typology of societies based on technological criteria: "Since it is predicted that technological variation is the primary determinant of variations among distributive systems, societies should be classified in technological terms, and this scheme of classification should be used to order the presentation of data" (p. 90).  He goes on to trace the origins of the typology he is about to propose largely to archaeologist V. Gordon Childe (1936), whose own typology of societies combined an emphasis on the mode of subsistence inherited from Enlightenment writers, particularly Anne-Robert-Jacques Turgot, and the archeological tradition, initiated by Danish museum curator Christian Thomsen, of classifying cultures according to the materials used to make tools and weapons (see also Lenski 1994).
The most immediate forerunner of Lenski’s typology is the one proposed by Goldschmidt (1959), in which societies are classified according to level of technological advance (compare Figure 3 and Figure 4 in Lenski 1966:92).  Lenski modifies Goldschmidt's typology by subdividing horticultural societies into a simple and an advanced type, adding categories for fishing and maritime societies, and merging together into a single type hunting and gathering societies, that Goldschmidt had subdivided into nomadic and settled.  While Lenski is well aware of the early work of Elman Service (1962), he does not mention Service's classificatory work as an influence; Fried (1967) and Service (1975) were published after Power and Privilege (1966) and could not have influenced the latter.  Thus Lenski's typology was proposed independently of some of the most popular classificatory schemes in use today (e.g., Diamond 1997:268-269).  Revised versions of the ecological-evolutionary typology were published in successive editions of Human Societies (Lenski 1970; Nolan and Lenski 1999).  Lenski (1994) provides a penetrating discussion of societal typologies, including his own.

Ecological-Evolutionary Framework
While the term ecological-evolutionary may sound like the creation of a slick promoter combining two fashionable buzzwords into an irresistible package, it in fact describes closely the principle of Lenski's typology.  It is indeed based on the combination of an evolutionary dimension of technological advance and an ecological dimension of environmental variation.
The evolutionary dimension refers to the level of overall efficiency of the subsistence technology of a society.  Each level on the efficiency scale is marked by the adoption of one crucial technological innovation.  Thus Lenski postulates what is in effect a Gutman scale of technological innovations, such that each new innovation marking the passage to a more advanced level presupposes all the earlier innovations.  In environments where plow cultivation is feasible, the sequence of societies at successive levels of the technological scale form what may be called the "main sequence" of socio-cultural evolution (although Lenski himself does not use this term).  The main sequence consists of the following types:
•	hunting and gathering societies (primordial type)
•	simple horticultural societies, characterized by farming using simple tools (hoe and digging stick) – appear about 8,000 BCE
•	advanced horticultural societies, characterized by metallurgy of copper and bronze
•	simple agrarian societies, characterized by the use of the plow – appear about 3,000 BCE
•	advanced agrarian societies, characterized by iron metallurgy
•	industrial societies, characterized by the use of machines powered by inanimate forms of energy – appear about 1750 CE
It is clear that Lenski considers the level of technology the primary dimension of the typology.  For example in Power and Privilege he writes:
The present typology is predicated on the assumption that there is an underlying continuum, in terms of which all societies can be ranked.  This continuum is a measure of a society's overall technological efficiency, i.e., the value of a society's gross product in international markets divided by the human energy expended in its production.  Unfortunately, this concept is not easily operationalized, and we are forced to rely on simpler and more obvious criteria for classificatory purposes.  This is the reason for classifying societies in terms of their basic techniques of subsistence.  Such data are readily available and seem highly correlated with overall technological efficiency.  (Lenski 1966, p. 93)
As discussed later, in Lenski's thinking technological efficiency does not exhaust the effects of a particular mode of subsistence on the system of stratification.  The mode of subsistence can affect the distributive system through causal paths other than efficiency of production.
The ecological dimension is added to reflect the fact that the main sequence is limited to environments in which plow cultivation is feasible.  Environments too arid for plow-based farming, or that present alternative subsistence opportunities because of proximity to large bodies of water, will support societies based on different subsistence strategies:
•	herding societies subsist by herding livestock in arid environments where plant cultivation is not practical
•	fishing societies subsist by fishing in environment with easy access to suitable bodies of water
•	maritime societies use their proximity to large bodies of water to derive their subsistence from maritime trade
Combining the two dimensions yields the ecological-evolutionary typology, represented in Figure 1.
------  Figure 1 about here  ------
The figure shows the main sequence toward the center of the environmental axis, with the specialized societies symbolically situated to the left (arid environments) and right (marine environments) of the horizontal axis and spread vertically along comparable levels of technological development.

Sociocultural Evolution and Social Inequality
In Figure 1 arrows show documented transitions between different types of societies.  Lenski's view of sociocultural evolution is not a naïve one of "progress".  In his view, sociocultural evolution takes place through two main mechanisms: 
•	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; examples are the disappearance of many native American societies following expansion of Europeans into the Western frontier of North America, or the retreat of Khoisan-speaking hunter-gatherers from extensive regions of Africa due to the advance of Bantu-speaking farmers
Lenski's discussion suggests that intersocietal selection is the predominant engine of evolution.  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 (Nolan and Lenski 1999:61-62).  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 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).  It is clear from Figure 1 hat Lenski’s evolutionary scheme is inherently multilinear, accommodating multiple paths of sociocultural evolution (see also Lenski 1994).
Much of Lenski's macrosociological work is devoted to understand the evolution of social inequality within his general ecological-evolutionary perspective.  His 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, depicting the trajectories of the "freedom" enjoyed by a member of the elite and by an average member of society in the course of sociocultural evolution.
------  Figure 2 about here  ------
Figure 2 focuses on the main sequence of sociocultural evolution, excluding specialized societies.  The curve labeled “Monotonic” depicts freedom for the average member of society as declining monotonically from the hunting and gathering to the agrarian type, improving only later with the onset of industrialization.  The theoretical reasons behind this postulated trend are twofold (Lenski 1966:89, Figure 2):
a.	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.
b.	Another part of the evolution of inequality is related to specific constraints or requirements of a given subsistence technology, which may directly affect "basic demographic, political, and productive patterns of organization" (Lenski 1966:89, Figure 2); for example, in herding societies the vulnerability of the herds to theft puts a premium on military might, which in turn may amplify hierarchical tendencies; 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.
The nadir of freedom for the average member of society is drawn to correspond to the agrarian stage.  I will argue later that there are distinct aspects of social inequality.  The notions of freedom (or "human rights") and inequality in the sense of a skewed distribution of material resources do not necessarily coincide, for example, so that while inequality in a distributional sense may peak in the late agrarian era, the nadir of freedom (in human rights terms) may correspond to the earlier, advanced horticultural stage, with freedom improving at the agrarian stage.  Such a pattern may be called an agrarian reversal.  It is depicted by the curve labeled “AG reversal” in Figure 2.

Empirical Implementation
From the earliest edition of Human Societies, Lenski (1970) used cross-cultural data to document his ecological-evolutionary theory.  Following his example I will use two comparative data sets to relate the ecological-evolutionary typology to dimensions of social inequality: the Ethnographic Atlas (hereafter EA), a data set with quantitative data on 1267 societies originally published by George P. Murdock (1967), and the Standard Cross-Cultural Sample (hereafter SS), 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).
Societies in the EA and SS can be assigned a societal type from information on (1) percentage dependence for subsistence on gathering, hunting, fishing, animal husbandry, and agriculture (meant as any type of farming); (2) use of plow animals (taken as indicator of the use of the plow for farming); and, (3) presence of metal working.  The societal types that are distinguishable in the EA and SS are listed in Table 1 with their simplified two-letters code.
------  Table 1 about here  ------
"Social inequality" is an elusive and multifaceted concept.  The rest of this paper examines how various dimensions of social inequality relate to the ecological-evolutionary typology, using the EA and SS data.

SOCIAL COMPLEXITY
A number of characteristics of stratification systems may be grouped under the heading of "social complexity".  These include population density, the presence of social classes, the number of hierarchical level, and the degree of specialization.  This section examines how these variables relate to the ecological-evolutionary typology.

Population Density
A more productive subsistence technology can support a larger population.  Thus, more productive technology should correspond by and large to greater population density.  Table 2 shows that density varies markedly by type of society.  Scanning down the last column corresponding to the highest density category (more than 100 persons per square mile), it appears that such high density is achieved by 0% of HG societies, 8.6% of SH societies, 30% of AH societies, and 61.3% of AG societies; the gradient in relative productivity is unmistakable.  Such high density is maintained by 18.2% of FI societies, but by none of the HE societies.  Herding presumably necessitates large expanses of territory with correspondingly low population densities. 
------  Table 2 about here  ------

Class Stratification Among Freemen
Table 3 is based on a variable in the EA that indicates the presence of different types of stratification systems, such as hereditary aristocracy or social classes proper.  These categories are not unambiguously ordinal so I recoded the variable into two categories denoting the absence (0) or presence (1) of class stratification among freemen.  There is an unambiguous pattern of monotonically increasing likelihood of class stratification as one goes up technology levels in the sequence HG (21.8%), SH (41.8%), AH (62.3%), and AG (85.7%).  Class stratification is present in 51.9% of FI societies, a level between that of SH and AH societies.  HE societies have high levels (79%), close to that of AG.  As HE societies are usually not as productive as AG ones, the high proportion of HE with class stratification may be due in part to defense-related imperative in the HE lifestyle, in addition to a productivity effect.
------  Table 3 about here  ------

Jurisdictional Levels Beyond Local Community
One of the best indicators of the vertical complexity of a society is the number of hierarchical levels in which a society is embedded beyond the local community.  Betzig (1986) calls this variable simply "hierarchy".  This variable is closely parallel to classical polity-oriented classification of societies (e.g., Service 1962, 1975; Fried 1967; Diamond 1997:268-269).
------  Table 4 about here  ------
Table 4 shows how type of society within the ecological-evolutionary typology is related to the five levels of this variable, from Code 1 (no jurisdictional level beyond local community) to Code 5 (4 levels or large state).  The percentages for Code 1 (no level beyond local community) trace once again the monotonic (and precipitous) decline in the sequence HG (88%), SH (62.3%), AH (24.6%), AG (12.8%), consistent with Lenski's overall scheme of the evolution of social inequality.  Likewise, combining the percentages for Codes 4 and 5 (state and large state), one sees that states are characteristic of AG societies (50.4%), and to a lesser extent of HE societies (%17.4) and AH (10.8%).  FI societies appear similar to SH, with the majority having at most one level of hierarchy beyond the local community.  I will show below that the number of hierarchical levels is strongly related (in a statistical sense) with the ecological-evolutionary typology.

Technological Specialization
In contrast to the number of hierarchical levels, which represents vertical complexity, the degree of specialization may be viewed as representing horizontal complexity.  Table 5 shows how Type of Society relates to the level of specialization.  The specialization scale has five levels corresponding to (1) no specialization, (2) pottery only, (3) loom weaving only, (4) metalwork only, and (5) specialization in metalwork, weaving, and pottery.  Note that the categories of this variable are not unquestionably ordinal (see the original discussion of this variable in Murdock and Provost 1971).  Since the specialization scale is only available in the SS, percentages are estimated from fewer observations.
------  Table 5 about here  ------
The monotonic pattern is once again in evidence for the main sequence from HG to AG.  For HG societies the modal level is no specialization (55.6%) while for AG the modal level is complete specialization of pottery, weaving, and metalwork (77.4%).  SH and AH societies are in between the HG and AG extremes.  Note how specialization in SH societies spans a wide range from none (20%) to complete (2.9%).  FI are in between HG and SH with respect to specialization, while HE resemble AH in this respect (although the comparisons for FI and HE involve small numbers of cases).

Explanatory Power of Ecological-Evolutionary Typology
In order to evaluate quantitatively the strength of the relationship between indicators of social complexity and the ecological-evolutionary typology Table 6 presents the results of regression analyses of the number of jurisdictional levels beyond the local community, and of the degree of specialization, treating each variable as if it were an interval scale.  Since even the ordinal nature of the variables, especially degree of specialization, may be reasonably questioned this is certainly a highly conservative approach, since any deviation from the equal intervals assumption would attenuate the fit of the regression model and lower the apparent explanatory power of the typology.
------  Table 6 about here  ------
Results for hierarchy are on the left of Table 6.  The ecological-evolutionary typology is represented by a set of indicators with values (0,1) for each type of society.  HG is omitted as the reference category.  The coefficients can be interpreted as deviations of the dependent variable from the HG average.  Except for FI, all regression coefficients are significant at better then the .001 level.  The coefficients for SH (.374), AH (1.119) and AG (2.136) exhibit a pattern of increasing magnitude reflecting the monotonic trend of Table 4.  The degree of hierarchy for FI is not significantly different than that for HG.  However the coefficient for HE is positive and significant, with a value intermediate between that for AH and AG.  The fit of the model (R2 = .407, adjusted R2 = .403) is nothing short of astonishing given the random noise introduced in the dependent variable by deviations from the assumption of an interval scale and perhaps even from that of an ordinal scale.
The high degree of fit is interesting in a broader perspective, since the scale of hierarchy is quite similar to the classical typologies based on the nature of the political system such as the ones of Service (1962, 1975), Fried (1967), or Diamond (1997:268-269).  It is theoretically significant that the ecological-evolutionary typology, constructed as it is entirely from variables related to subsistence technology, should be able to reproduce so well other typologies based on entirely different variables representing aspects of political organization.
Results for the specialization scale are shown on the right of Table 6.  The pattern of coefficients is qualitatively very similar to that for hierarchy: there is a monotonic trend in the positive coefficients for SH, AH, and AG; the coefficient for FI is not significantly different from 0 (i.e., from that for HG); the coefficient of HE is positive and significant, with a value intermediate (this time) between that for SH and AH.  The fit of the model (R2 = .578, adjusted R2 = .565) is even stronger than for hierarchy, despite the fact that the ordinality assumption is perhaps even more questionable for the specialization scale than it is for hierarchy.    

SOCIAL RIGIDITY, INEQUALITY, AND FREEDOM
The previous section examined features of society that could be grouped under the general heading of social complexity.  The general evolutionary pattern is one of increasing complexity along the HG, SH, AH, AG sequence, less complexity for FI, and a higher level of complexity for HE, similar to the AG level.  Other dimensions of stratification systems relate more explicitly to the invidious nature of inequality.  These include measures of social rigidity (manifested in inheritance of the position of headman, and inheritance of real property), the practice of slavery, a composite measure of the degree of stratification, and the presence of despotism.  I explore these dimensions in this section.

Inheritance of Leadership Position
The left panel of Table 7 shows the percentage of societies in which the office of local headman is inherited by the patrilineal or matrilineal heir.  The evolutionary pattern is different from the one observed before.  There is the beginning of a monotonic upward trend in inheritance of headman position in the sequence HG (52.6%), SH (53%), and AH (65.6%).  But then the monotonic increase is reversed with AG (29.6%).  Figures for FI (55.8%) and HE (61.7%) are both higher than for AG.  Instead of a monotonic progression with a peak for AG, there is now a downturn for the AG type.  Chance variation is an unlikely cause, since the AG percentage is supported by 98 cases.  Furthermore, the dip in the likelihood of inheritance of headman position is not due (as one might surmise) to the fact that AG societies choose their leaders by a method even more invidious than inheritance.  In fact, a tabulation (not shown) of the original variable on which Table 7 is based reveals that the modal method of succession in AG is "election or other formal consensus, nonhereditary" (37.8%, more than for any other type of society), which clearly represents a more "democratic" method than inheritance.  We now examine other variables to see if this new pattern is found for other dimensions of inequality.
------  Table 7 about here  ------

Inheritance of Real Property
Another possible measure of social rigidity is inheritance of real property (land).  Here one would expect at the outset that the nature of the predominant subsistence might have effects on inheritance of land independent of productivity, since the value of owning land must vary in relation to technology of production.
In the right panel of Table 7 the percentage of societies where inheritance of land is absent exhibits the familiar monotonic decline in the sequence HG (83.2%), SH (21.8%), AH (6.9%), and AG (2.7%).  Thus, as the productivity of land increases and as the same area of land represents an increasingly valuable investment, one sees a strengthening of inheritance rules.  Both FI and HE societies are more likely to have no rules of inheritance, perhaps because land is not a main source of subsistence (in FI), or because the vast expanses of land needed for herding preclude close control through private ownership (in HE).  In any case, there is no evidence of AG reversal here.

Composite Measure of Social Stratification
The social stratification scale in the SS combines the presence of slavery and of classes and/or castes to construct a composite scale of social stratification (Murdock and Provost 1971).  While the scale is presented as capturing a homogeneous dimension with ordinal steps, one might doubt that the presence of slavery and the number of social classes can be so easily combined.  In any case Table 8 exhibits again the monotonic pattern of increase in the scale from HG to AG, with no AG reversal.  FI and HE have similar low modal values corresponding to Code 2 (hereditary slavery).
------  Table 8 about here  ------

Slavery
Table 9 shows the percentage of societies in which slavery is "present" versus "absent or nearly absent".  Presence of slavery has face validity as a strong indicator of invidious inequality in a society.  In fact, it is quite remarkable how frequent slavery is among human societies represented in the EA and SS: as the marginals of Table 9 show, close to half (48%) of the societies in the EA practice some form of slavery. 
The percentage with slavery present at first increases monotonically in the sequence HG (11.6%), SH (19.3%), AH (84.1%), and then drops precipitously for AG societies (43.7%).  In this case FI (50.9%) and especially HE (81.7%) are more likely than AG to have some form of slavery.  Therefore presence of slavery is another instance of AG reversal, in which a monotonic trend of increasing "invidiousness" breaks down and is reversed at the AG stage.
------  Table 9 about here  ------

Despotism
What is perhaps the most direct measure of invidious social inequality is the indicator of despotism contributed by Betzig (1986) for a subset of the SS data set.  Betzig defines despotism as "the extent to which one individual, at the head of the social hierarchy, is able to exploit his position of strength when a conflict of interests arises, effecting a biased result in his favor.  It does not include such asymmetry over slaves nor over members of the household" (Divale 2000:196, V1134).  There is no doubt from Betzig's (1986) descriptions of executions and tortures that what she means is real despotism, not a slightly authoritarian style of government.  The total number of cases available is only 83, due in part to Betzig's decision to exclude SS cases that could not be considered fully autonomous politically at the time of the principal ethnographic description of the society.
The right panel of Table 9 shows the percentages of societies in which despotism is present.  The monotonic pattern is evident in the sequence HG (0%), SH (11.1%), and AH (64.3%).  Then despotism dips noticeable for the AG type (13.3%).  FI (11.1%) and HE (0%) have even smaller incidences of despotism, but the observations supporting these percentages are few (9 and 6 cases, respectively).  The evolutionary pattern for despotism thus appears to be another case of AG reversal.  It is unfortunate that this intriguing finding is not supported by a larger data set. 

IDEOLOGICAL ASPECTS OF INEQUALITY
A somewhat more indirect way to assess the degree of social inequality is to look for ideological traces of subordination and conflict.  Following Human Societies this section examines reflections of inequality in the kinds of games people play, and in the values societies inculcate in children (Nolan and Lenski 1999:109-110).

Games of Strategy
Table 10 shows percentages of societies of a given type that have games of strategy.  A game of strategy is one that, like chess, checkers or tic-tac-toe, does not involve any random element and whose outcome therefore depends entirely on strategic decisions on the part of the players.  The connection with social stratification is the observation that games of strategy often seem to represent "simulations" of such human activities as warfare, competition, and maneuvering within a social hierarchy.  (The relationship is sometimes transparent, as in the case of chess with warfare.)  Thus it might be conjectured that more unequal societies, or those characterized by more conflict or rivalries, would also be more likely to appreciate games of strategy.
Table 10 reveals the remarkable fact that none of the 131 HG societies have games of strategy, presumably because warfare is relatively infrequent in these societies, and there is not much of a hierarchy in which to maneuver.  The presence of games of strategy increases in SH (10.4%) and AH (59.1%).  The 56.8% for AG represent, if not a significant reversal, at least the absence of further increase relative to AH.  FI has a very low figure (2.9%), similar to HG, perhaps because people in FI societies are similarly subject to the random vagaries of the weather and the unpredictable movements of the game.  HE has a high 53.8% figure, similar to AG.
------  Table 10 about here  ------

Importance of Self-Reliance and Obedience in Socialization
The SS has data on the values inculcated in childhood.  Two of these values are self-reliance and obedience.  As a reflection of the stratification system, self-reliance might represent the relative independence of the individual vis-à-vis the social system, perhaps an indicator of relative equality and freedom.  One would also expect self-reliance to be emphasized in societies where individuals are likely to face unexpected and threatening circumstances in the course of their daily activities.  Obedience, on the other hand, is likely to be emphasized in societies characterized by strong hierarchies.  In such societies, obedience may be essential for survival, if only to avoid running afoul of vengeful leaders.  
------  Figure 3 about here  ------
Figures 3 shows the mean values of the self-reliance and obedience scales by type of society.  Each variable is calculated as the average of non-missing values for the emphasis on the value in the socialization of early boys, early girls, late boys, and late girls.  Figure 3 shows a monotonic decrease in the emphasis on reliance from HG to AG.  However, mean self-reliance jumps up for FI and HE, up to the same high levels as for HG.  It may be that imperatives of the production technology are more important than the degree of stratification in the social hierarchy in determining emphasis on self-reliance.  The pattern of declining emphasis on self-reliance from HG to AG, and the high values for FI and HE, may simply reflect the fact that daily life in AG societies produces fewer unexpected events for people than in HG, FI, and HE societies.  Thus emphasis on self-reliance might not be primarily a reflection of different degrees of inequality.
Emphasis on obedience, in a mirror pattern, increases monotonically from HG to AG.  It is tempting to interpret this trend as reflecting ideological adaptation to types of societies characterized by increasing degrees of stratification.  Emphasis on obedience declines precipitously for FI, as if obedience is much less necessary in societies where dealing with natural elements is crucial for survival.  Interestingly, mean obedience shoots up for HE to a level as high as the one for AG.  This suggests that people in HE societies value both self-reliance and obedience: self-reliance to deal with the many unexpected natural and human contingencies, and obedience to function within the strong hierarchical order that characterizes these societies.  The combination of self-reliance and obedience represents, of course, the quintessence of military virtue.

SEXUAL AND REPRODUCTIVE INEQUALITY

Reproductive Inequality and the Accumulation of Women
By "sexual and reproductive inequality" in this paper I mean inequality among men in access to women for sexual and reproductive purposes in a context of polygyny.  In the pre-sociobiological social sciences prior to the last quarter of the 20th Century most social scientists dealt with the variation in marriage customs among human societies in a largely descriptive perspective.  It was recognized that most societies permit polygyny (one man, several wives), a minority prescribe strict monogamy for everyone, and very few practice polyandry (one woman, several husbands).  Variation in marriage customs was viewed as resulting from cultural preferences in the same way as choice of residence at marriage or emphasis on the patrilineal or matrilineal lines in tracing descent.  Marriage customs, and polygyny in particular, were typically not approached as mechanisms of stratification.  This largely descriptive and cultural emphasis is reflected in the kind of data considered worth keeping for comparative analysis.  It is clear that information on the distribution of wives among men was not considered relevant or interesting.   This is unfortunate since the distribution of wives can provide measures of social inequality that are at once quantitative and strictly comparable across the most diverse social settings.
Traditional views on the significance of multiple wives seem to fall into two categories: (1) multiple wives are a mark of high status, a kind of perk akin to fast cars or a corner office; so for example anthropologist Holmberg (1950, cited by Nolan and Lenski 1999:104) says of the Siriono headman "[a]s a mark of status, however, a headman always possesses more than one wife" (pp. 59-60; my emphasis); (2) multiple wives can be put to work producing goods, so the polygynist is, in effect, a kind of early capitalist exploiting his wives' labor (e.g., Divale 2000:137, V860).  While these descriptions may seem facetious they are not.  It is in fact fascinating to see grown men and women gravely debating whether women are more advantageously viewed as status symbols or as producers of surplus, while any adolescent boy with raging hormones can fantasize a more perspicuous theory on the true value of women.
The ascending evolutionary perspective on the role of sex in social relations (under such names as sociobiology, evolutionary psychology, or behavioral ecology) is based on the theory of parental investment (Trivers 1972).  The fundamental idea is that in humans, as in many other (but not all) species, males invest typically less in the offspring than females, who invest a great deal in the form of a long gestation and many years of care of the offspring after birth.  Investing little themselves, males are selected to compete for sexual access to females, whose heavy parental investment constitutes a limiting resource on male reproduction.  This competition process underlies the emergence of the dominance hierarchies that are widespread in the animal world and largely determines human patterns of polygyny manifested in a skewed distribution of wives among men.  The value of multiple wives is not primarily as a symbol of status, nor as a source of surplus value.  Women are valuable for men, worth accumulating and fighting for, because they invest so much effort in their offspring.  Women themselves in their role for sex and reproduction are "the real thing", the object of all the fuss (van den Berghe 1979; Daly and Wilson 1983; Nielsen 1994; Lopreato and Crippen 1999).   
In an evolutionary perspective inequality in the distribution of wives among men is a fundamental component of overall inequality in a society.  Two measures are available that capture different aspects of sexual and reproductive inequality.

Polygyny
The traditional distinction between "occasional" and "common" polygyny is useless in a sexual competition perspective, because it confounds situations that differ radically in the degree of inequality.  The best one can do is to use existing information to classify societies as strictly monogamous (so that a man cannot legally have more than one wife) and those that are not, and thus in which women are potentially distributed in a highly skewed fashion.  The right panel of Table 10 shows the distribution of monogamy / polygyny by type of society.  (I have counted the four polyandrous societies in the EA as monogamous.)
As the marginals of Table 10 remind us, strict monogamy (absence of polygyny) is practiced by only a minority of human societies: 153 out of 857 in the EA, or 17.9%.  The AG type has by far the largest incidence of monogamy (41.5%).  Along the main sequence of sociocultural evolution the high monogamy figure for AG represents a real jump relative to the immediately preceding type AH, where the incidence of monogamy is only 6.5%.  Since the data set is rather large (the 41.5% figure for AG is supported by 135 cases) we can be reasonably sure that this instance of AG reversal is not an artifact.  Thus, once again, it appears that for this dimension AG is associated with less inequality, and the nadir of inequality corresponds to AH, contrary to the monotonic pattern of increasing inequality from HG to AG originally postulated by Lenski.

Maximum Harem Size
A better measure of inequality in the distribution of women than the monogamy-polygyny dichotomy is the actual measure of maximum harem size provided by Betzig (1986) for a subset of cases in the SS (see also Alexander, Hoogland, Howard, Noonan, and Sherman 1979).  Maximum harem size is defined as the number of conjugal relationships enjoyed by the man at the head of the social hierarchy (or, where there is no hierarchy, the most polygynous man).  The scale codes number of wives and concubines into intervals as 1 = 3 or fewer, 2 = 4 to 10, 3 = 11-100, 4 = more than 100.
------  Table 11 about here  ------
Table 11 reveals clear differences in harem size among types of societies.  Societies of the HG and SH types are concentrated in categories 1 and 2, at the low end of the scale.  AH societies tend to lie at the other extreme, with a plurality (45.5%) in category 4 (over 100 wives).  By contrast AG societies exhibit a sharp decline in the degree of inequality, with the majority (61.5%) in category 1 (3 wives or fewer).  FI and HE exhibit patterns not unlike that for HG, SH, or AG societies, but these percentages are based on very few observations.  In any case these results suggest that the equality nadir is situated in AH rather than AG societies.  This clear instance of AG reversal in the trend of monotonically increasing inequality is unfortunately based on a total of only 77 observations.  While the chi-square is significant at p = .038, the large number of sparse cells renders this significance estimate suspect.

SOCIOCULTURAL EVOLUTION REVISITED: WAS THERE AN AG REVERSAL?

Evidence for AG Reversals
Table 12 summarizes the empirical results.  The pattern of the relationship between a dimension of inequality and type of society is classified as either Monotonic (the dimension increases monotonically over the sequence HG, SH, AH, AG) or AG Reversal (the dimension increases over the sequence HG, SH, AH, but then decreases from AH to AG).  The table shows that there are five clear instances of AG reversals (excepting Games of Strategy, for which the decline from AH to AG is very small and statistically non significant).  One instance of reversal corresponds to a measure of social rigidity (inheritance of headman's office), two concern clear measures of (absence) of freedom (presence of slavery and of despotism), and two correspond to the measures of sexual and reproductive inequality (polygyny allowed and maximum harem size).  None of the measures of social complexity exhibits the AG reversal pattern.
------  Table 12 about here  ------
This empirical evidence suggesting AG reversals for some dimensions of inequality harks back to a traditional perspective associating human progress with the emergence of "civilization" which, connoting the emergence of cities, is closely identified with the AG type of society.  It is compatible with the old-fashioned notion that, however harsh the punishment meted out in early agrarian codes of justice, such as Hammurabi's, these codes represented progress in freedom relative to earlier stages of sociocultural development.
AG reversals present empirical as well as theoretical challenges.

Empirical Challenge of AG Reversals
Among other dimensions, the AG reversal appears clearly in two dimensions related to sexual and reproductive inequality.  Betzig's (1986) measure of maximum harem size is available only for a subset of the SS.  An immediate empirical task would be to obtain, for at least the whole SS and perhaps for the entire EA: (1) maximum harem size (Betzig 1986); the advantage of this measure is that it is perhaps easiest to find in ethnographic sources; a drawback is that, like the range as a measure of dispersion, it may not be a robust statistic (Alexander et al. 1979); (2) sufficient information on the distribution of wives among men to calculate a summary measure of inequality, such as the Gini coefficient; (3) sufficient information on the distribution of reproductive success (number of offspring) for men and women separately to estimate the effective rate of polygyny, calculated as the ratio of the variance in reproductive success for men to the variance in reproductive success for females; this is a measure of reproductive inequality among males (Daly and Wilson 1983).

Theoretical Challenge of AG Reversals
What are the theoretical implications of AG reversals?  Confirmation of the AG reversal pattern for important dimensions of social inequality would pose a major theoretical challenge while opening the door to new theoretical insights.
AG reversals challenge traditional explanations of trends in social inequality and human freedom.  Lenski's historical scheme as proposed in Power and Privilege and Human Societies describes freedom for the average member of society as declining monotonically along the "main sequence" of types HG, SH, AH, AG, to reach a nadir in AG societies.  Freedom for ordinary people does not begin to improve until the onset of industrialization.  The theoretical interpretation of this monotonic pattern is straightforward.  The monotonic decline in freedom is associated with the parallel increase in the size of the surplus made possible by technological advances amplifying the productivity of human labor.  A greater surplus can be taken away from the producers to feed a more complex (and unequal) social structure.  The reversal in the freedom trend during industrialization can then be attributed by mechanisms inherent to the "logic of industrialization", such as greater dependence of industrial production on human capital, the spread of education, and the emergence of a middle class.  If the upturn in freedom occurred earlier during the agrarian era, industrialization can no longer account for the improvement in the human condition.  Thus theoretical explanations for the upturn in freedom need to be at least adapted, and perhaps overhauled entirely.  The new theoretical question becomes: What mechanisms, already operating in the agrarian system, are powerful enough to begin reversing the trend of increasing accumulation of power and resources by the elites?
The finding that the AG reversal takes place in the context of a decline in maximum harem size, as well as the extension of strict monogamy, certainly suggests that there may be a connection between the upturn in human freedom and the watershed in sociocultural evolution represented by the spread of socially imposed monogamy (or socially imposed limitations on polygyny, as common today in the Moslem world).  Thus the debate that has recently re-emerged in sociology about the origins of socially imposed monogamy may be extremely relevant to the issue of the AG reversal (Kanazawa and Still 1999; see also MacDonald 2001; Sanderson 2001; Kanazawa 2001a, b).  Theoretical questions to be posed in this context are:  What were the mechanisms of the shift to socially imposed monogamy or limited polygyny?  Are these mechanisms associated with the AG subsistence system, and if so how?
	These are obvious questions for further research.
 
SUMMARY AND CONCLUSION
Gerhard Lenski (1966) originally developed his influential typology of human societies for the very purpose of illuminating variation in the nature of distributive systems among societies.  The analyses carried out in this paper show that the typology constitutes a powerful predictor of many aspects of stratification systems.
One generalization proposed by Lenski and co-workers concerns secular trends in human freedom for the average member of society over the course of socio-cultural evolution (see Figure 2).  Lenski proposes that freedom for the average person has declined monotonically along the sequence of societal types HG, SH, AH, AG, to reach its nadir in agrarian societies, resuming on an upward course only with the advent of industrialization.
While many dimensions of human inequality do indeed trace such a monotonic trajectory from the HG to the AG type, the analyses in this paper have shown that for other dimensions there appears to be a reversal in the trend at the agrarian stage.  Such an AG reversal pattern suggests that human freedom started improving in AG societies, and that the nadir should therefore be located to correspond to the AH type of society.  AG reversals have important implications for understanding socio-cultural evolution.
In the course of the analysis, I have argued that sexual and reproductive inequality, as measured by the presence of polygyny versus socially imposed monogamy, or better still by a measure of the skewed distribution of wives among married men such as Betzig's (1986) maximum harem size, may provide one of the best comparative measure of inequality among societies that otherwise may differ widely in life-style and level of development.  This realization has important implications for future empirical research, such as the need for constructing measures of sexual and reproductive inequality for a larger set of societies; the desirability of examining shifts to socially imposed monogamy or limited polygyny in the theoretical context of social stratification (not only family systems); and the prospect of relating the study of human stratification systems to the study of dominance orders in the rest of the animal world within the emerging Darwinian approach to social evolution (van den Berghe 1974, 1979; Maryanski and Turner 1992; Lopreato and Crippen 1999). 

REFERENCES
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Betzig, Laura.  1986.  Despotism and Differential Reproduction: A Darwinian View of History.  New York: Aldine.
Blumberg, Rae. 1978.  Stratification: Socioeconomic and Sexual Inequality.  Dubuque, Iowa: WM. C. Brown.
Chafetz, Janet Saltzman.  1984.  Sex and Advantage.  Totowa, NJ: Rowman and Allanheld.
Childe, V. Gordon.  1936.  Man Makes Himself.  London, England: Watts.
Daly, Martin and Margo Wilson.  1983.  Sex, Evolution, & Behavior.  (2nd edition.)  Belmont, CA: Wadsworth.
Diamond, Jared.  1997.  Guns, Germs, and Steel: The Fates of Human Societies.  New York: Norton.
Divale, William.  2000.  Pre-Coded Variables for the Standard Cross-Cultural Sample, Volume I and II.  Jamaica, NY: York College, CUNY.  [Distributed by World Cultures.]
Fried, Morton.  1967.  The Evolution of Political Society.  New York: Random House.
Gray, J. Patrick.  1998.  Ethnographic Atlas Codebook.  World Cultures 10(1):86-136.  [Distributed by World Cultures.]
Goldschmidt, Walter.  1959.  Man's Way: A preface to the Understanding of Human Society.  New York: Holt.
Heise, David, Gerhard Lenski, and John Wardwell.  1976.  “Further Notes on Technology and the Moral Order.”  Social Forces 55:316-317.
Holmberg, Allan.  1950.  Nomads of the Long Bow: The Siriono of Eastern Bolivia.  Washington, DC: Smithsonian Institution.
Kanazawa, Satoshi and Mary C. Still. 1999. "Why Monogamy?" Social Forces 78:25-50. 
Kanazawa, Satoshi. 2001. "Science vs. History: A Reply to MacDonald." Social Forces 80:349-352.
Kanazawa, Satoshi. 2001. "A Bit of Logic Goes a Long Way: A Reply to Sanderson." Social Forces 80:337-341.
Lenski, Gerhard.  [1966] 1984.  Power and Privilege.  Chapel Hill, NC: University of North Carolina Press.
Lenski, Gerhard.  1970.  Human Societies: A Macrolevel Introduction to Sociology.  (1st edition.)  New York: McGraw-Hill.
Lenski, Gerhard and Jean Lenski.  1974.  Human Societies: An Introduction to Macrosociology.  (2nd edition.)  New York: McGraw-Hill.
Lenski, Gerhard, Patrick Nolan, and Jean Lenski.  1995.  Human Societies: An Introduction to Macrosociology.  (7th edition.)  New York: McGraw-Hill.
Lenski, Gerhard.  1994.  "Societal Taxonomies: Mapping the Social Universe."  Annual Review of Sociology 20:1-26.
Lopreato, Joseph and Timothy Crippen.  1999.  Crisis in Sociology: The Need for Darwin.  New Brunswick, NJ: Transaction.
MacDonald, Kevin.  2001.  "Theoretical Pluralism and a Historical Complexity: A Comment on Kanazawa and Still."  Social Forces 80:343-347.
Maryanski, Alexandra and Jonathan H. Turner.  1992.  The Social Cage: Human Nature and the Evolution of Society.  Stanford, CA: Stanford University Press.
Murdock, George P.  1967.  Ethnographic Atlas.  Pittsburgh, PA: Pittsburgh University Press.
Murdock, George P. and Caterina Provost.  1971.  "Cultural Complexity."  Ethnology 12:379-392.  
Murdock, George P. and Douglas R. White.  1969.  "Standard Cross-Cultural Sample."  Ethnology 8:329-369.
Nielsen, François.  1994.  "Sociobiology and Sociology."  Annual Review of Sociology 20:267-303.
Nolan, Patrick and Gerhard Lenski.  1999.  Human Societies: An Introduction to Macrosociology.  (8th edition.)  New York: McGraw-Hill.
Sanderson, Stephen K. 2001. "Explaining Monogamy and Polygyny in Human Societies: Comment on Kanazawa and Still."  Social Forces 80:329-335.
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Service, Elman.  1975.  Origins of the State and Civilization.  1975.  New York: Norton.
Trivers, Robert L.  1972.  “Parental Investment and Sexual Selection.”  Pp. 136-179 in Sexual Selection and the Descent of Man 1871-1971, edited by Bernard G. Campbell.  Chicago, IL: Aldine.
van den Berghe, Pierre L.  1974.  "Bringing Beasts Back In."  American Sociological Review 39:777-788.
van den Berghe, Pierre L.  1979.  Human Family Systems: An Evolutionary View.  New York: Elsevier.

Table 1.  Types of Societies in EA and SS

Code	Type of Society	N in EA	N in SS	
HG	Hunting & Gathering	174	27	
SH	Simple Horticultural	162	35	
AH	Advanced Horticultural	263	40	
AG	Agrarian	135	31	
FI	Fishing	60	11	
HE	Herding	77	16	
Total		871	160	

Note: EA = Ethnographic Atlas, SS = Standard Cross-Cultural Sample.  See Divale (2000).

Table 2.  Population Density by Type of Society

	Persons per Square Mile			
	< 1 	1-5 	5.1-25 	26-100	> 100	Total	N	
HG	77.8	11.1	7.4	3.7	0.0	100.0	27	
SH	25.7	14.3	22.9	28.6	8.6	100.0	35	
AH	2.5	10.0	30.0	27.5	30.0	100.0	40	
AG	0.0	6.5	6.5	25.8	61.3	100.0	31	
FI	36.4	9.1	18.2	18.2	18.2	100.0	11	
HE	37.5	43.7	6.2	12.5	0.0	100.0	16	
Total	25.6	13.8	16.9	21.3	22.5	100.0		
N	41	22	27	34	36		160	

Note: Type of Society: see Table 1.  Population Density is SS V156; Chi-square 109.0, 20 df, p<.000; more than 20% of fitted cells are sparse (n<5) so significance level is suspect.

Table 3.  Presence of Class Stratification by Type of Society

	%Absent	% Present	N	
HG	78.2	21.8	165	
SH	58.2	41.8	158	
AH	37.7	62.3	236	
AG	14.3	85.7	126	
FI	48.1	51.9	54	
HE	21.0	79.0	62	
Total	45.8	54.2		
N	367	434	801	

Note: Type of Society: see Table 1.  Class Stratification recoded from EA V66 as 0 (Absent) if V66 is 1 = Absence of class stratification among freemen, 1 (Present) if V66 is 2 = Wealth distinctions, 3 = Elite based on control of land or other resources, 4 = Dual (hereditary aristocracy), or 5 = Complex (social classes); Chi-square 151.7, 5 df, p<.000.

Table 4.  Jurisdictional Hierarchy Beyond Local Community by Type of Society

	Jurisdictional Hierarchy Scale			
	1	2	3	4	5	Total	N	
HG	88.0	12.0	0.0	0.0	0.0	100.0	167	
SH	62.3	26.5	10.5	0.6	0.0	100.0	162	
AH	24.6	38.5	26.2	10.0	0.8	100.0	260	
AG	12.8	18.4	18.4	31.2	19.2	100.0	125	
FI	67.9	28.6	3.6	0.0	0.0	100.0	56	
HE	10.1	42.0	30.4	17.4	0.0	100.0	69	
Total	44.5	27.5	15.6	9.3	3.1	100.0		
N	373	231	131	78	26		839	

Note: Type of Society: see Table 1.  Jurisdictional Hierarchy Beyond Local Community is EA V33: 1 = No political authority beyond local community, 2 = One level (petty chiefdom), 3 = Two levels (larger chiefdom), 4 = Three levels (state), 5 = Four levels (large state); Chi-square 483.8, 20 df, p<.000.

Table 5.  Technological Specialization by Type of Society

	1	2	3	4	5	Total	N	
HG	55.6	18.5	22.2	3.7	0.0	100.0	27	
SH	20.0	25.7	31.4	20.0	2.9	100.0	35	
AH	2.5	0.0	7.5	70.0	20.0	100.0	40	
AG	0.0	0.0	6.5	16.1	77.4	100.0	31	
FI	45.5	18.2	18.2	18.2	0.0	100.0	11	
HE	18.8	6.2	12.5	62.5	0.0	100.0	16	
Total	19.4	10.6	16.3	33.1	20.6	100.0		
N	31	17	26	53	33		160	

Note: Type of Society: see Table 1.  Technological Specialization is SS V153: 1 = None, 2 = Pottery only, 3 = Loom weaving only, 4 = Metalwork only, 5 = Smiths, weavers, potters; Chi-square 158.8, 20 df, p<.000; more than 20% of fitted cells are sparse (n<5) so significance level is suspect.

Table 6.  OLS Regressions of Jurisdictional Hierarchy Beyond Local Community and Technological Specialization on Type of Society: Unstandardized Coefficients (b) and t-Ratios (t)

	Jurisdictional Hierarchy	Technological Specialization	
Independent
Variable	b	t = b/se		b	t = b/se		
Constant	1.120	16.732	*** a	1.741	9.725	***	
HG (ref.)	--	--		--	--		
SH	0.374	3.922	***	.859	3.607	***	
AH	1.119	13.044	***	2.309	9.968	***	
AG	2.136	20.885	***	2.969	12.126	***	
FI	0.237	1.777		.350	1.053		
HE	1.431	11.562	***	1.447	4.930	***	
R2	.407			.578			
Adj. R2	.403			.565			
N	839			160			

Note: Type of Society indicators: see Table 1.  Jurisdictional Hierarchy Beyond Local Community: see Table 4.  Technological Specialization: see Table 5.
a *** p < .001 (2-tailed tests) 

Table 7.  Inheritance of Office of Local Headman and Inheritance of Real Property (Land) by Type of Society
 
	Inheritance of
Office of Local Headman	Inheritance of
Real Property	
	% Absent	% Present	N	% Absent	% Present	N	
HG	47.4	52.6	133	83.2	16.8	101	
SH	47.0	53.0	132	21.8	78.2	87	
AH	34.4	65.6	218	6.9	93.1	218	
AG	70.4	29.6	98	2.7	97.3	110	
FI	44.2	55.8	43	51.4	48.6	35	
HE	38.3	61.7	47	31.4	68.6	51	
Total	45.6	54.4		25.7	74.3		
N	306	365	671	155	447	602	

Note: Type of Society: see Table 1.  Inheritance of Office of Local Headman calculated from EA V72 as 1 (Present) if V72 is 1 = Patrilineal heir or 2 = Matrilineal heir, and 0 (Absent) otherwise; Chi-square 36.6, 5 df, p<.000.  Inheritance of Real Property is coded from EA V74 as 0 (Absent) if V74 = 1, Absence of individual property rights or rules, and 1 (Present) otherwise; Chi-square 258.9, 5 df, p<.000.

Table 8.  Composite Social Stratification Scale by Type of Society

	1	2	3	4	5	Total	N	
HG	92.6	7.4	0.0	0.0	0.0	100.0	27	
SH	42.9	37.1	14.3	5.7	0.0	100.0	35	
AH	10.0	32.5	20.0	20.0	17.5	100.0	40	
AG	3.2	19.4	3.2	6.5	67.7	100.0	31	
FI	18.2	45.5	9.1	27.3	0.0	100.0	11	
HE	18.8	50.0	0.0	25.0	6.2	100.0	16	
Total	31.3	29.4	9.4	11.9	18.1	100.0		
N	50	47	15	19	29		160	

Note: Type of Society: see Table 1.  Social Stratification Scale is SS V158: 1 = Egalitarian, 2 = Hereditary slavery, 3 = 2 social classes, no castes/slavery, 4 = 2 social classes, castes/slavery, 5 = 3 social classes or castes, with or without slavery; Chi-square 138.0, 20 df, p<.000; more than 20% of fitted cells are sparse (n<5) so significance level is suspect.

Table 9.  Presence of Slavery and Presence of Despotism by Type of Society

	Slavery	Despotism	
	% Absent	% Present	N	% Absent	% Present	N	
HG	88.4	11.6	164	100.0	0.0	21	
SH	80.7	19.3	150	88.9	11.1	18	
AH	15.9	84.1	239	35.7	64.3	14	
AG	56.3	43.7	119	86.7	13.3	15	
FI	49.1	50.9	57	88.9	11.1	9	
HE	18.3	81.7	60	100.0	0.0	6	
Total	52.0	48.0		83.1	16.9		
N	410	379	789	69	14	83	

Note: Type of Society: see Table 1.  Slavery is calculated from EA V70 as 0 (Absent) if V70 is 1 = Absence or near absence (of slavery), and 1 (Present) otherwise; Chi-square 289.6, 5 df, p<.000.  Despotism is SS V1134 contributed by Betzig (1986): 0 = Despotism absent (recoded from 1), 1 = Despotism present (recoded from 2).  See the SS codebook (Divale 2000) and Betzig (1986) for detailed discussion; Chi-square 28.7, 5 df, p<.000; more than 20% of fitted cells are sparse (n<5) so significance level is suspect.

Table 10.  Presence of Games of Strategy and Presence of Polygyny by Type of Society

	Games of Strategy	Polygyny	
	% Absent	% Present	N	% Absent	% Present	N	
HG	100.0	0.0	131	10.5	89.5	172	
SH	89.6	10.4	67	24.8	75.2	157	
AH	40.9	59.1	66	6.5	93.5	261	
AG	43.2	56.8	44	41.5	58.5	135	
FI	97.1	2.9	34	12.1	87.9	58	
HE	46.2	53.8	13	21.6	78.4	74	
Total	77.7	22.3		17.9	82.1		
N	276	79	355	153	704	857	

Note: Type of Society: see Table 1.  Presence of games of strategy calculated from EA V35 as missing if V35 is 0, 1 (Present) if V35 is 4 = Strategy only, 6 = Skill and strategy, 7 = Chance and strategy, or 8 = All [types of games], and 0 (Absent) otherwise; Chi-square 139.9, 5 df, p<.000.  Polygyny is calculated from EA V9 Marital Composition: Monogamy and Polygamy as 0 (Absent) if V9 is 1 = Independent nuclear, monogamous or 7 = Independent polyandrous families (n=4), and 1 (Present) otherwise; Chi-square 87.9, 5 df, p<.000.

Table 11.  Maximum Harem Size by Type of Society

	Simultaneous Conjugal Relations		
	3 or less	4 to 10	11 to 100	> 100 	Total	N	
HG	52.4	38.1	4.8	4.8	100.0	21	
SH	44.4	38.9	16.7	0.0	100.0	18	
AH	9.1	18.2	27.3	45.5	100.0	11	
AG	61.5	15.4	15.4	7.7	100.0	13	
FI	44.4	33.3	11.1	11.1	100.0	9	
HE	60.0	20.0	20.0	0.0	100.0	5	
Total	45.5	29.9	14.3	10.4	100.0		
N	35	23	11	8		77	

Note: Type of Society: see Table 1.  Maximum Harem Size is SS V1133 contributed by Betzig (1986) and defined as "Simultaneous conjugal relations with concubines and wives that the individual at the head of the social hierarchy (or, where there is no hierarchy, the most polygynous man), enjoys".  Codes are 1 = 3 conjugal relationships or less, 2 = 4-10 conjugal relationships, 3 = 11-100 conjugal relationships, 4 = More than 100 conjugal relationships; Chi-square 26.0, 15 df, p =.038; more than 20% of fitted cells are sparse (n<5) so significance level is suspect. 

Table 12.  Evolutionary Patterns for Dimensions of Social Inequality

Dimension of Inequality	Table or Figure	Evolutionary Pattern	
Measures of Social Complexity		
Population density	T2	Monotonic	
Class stratification	T3	Monotonic	
Hierarchy (# levels)	T4, T6	Monotonic	
Specialization scale	T5, T6	Monotonic	
Measures of Social Rigidity, Inequality, and Freedom	
Inheritance of headman office 	T7	AG Reversal	
Inheritance of real property	T7	Monotonic	
Stratification scale	T8	Monotonic	
Slavery present	T9	AG Reversal	
Despotism present	T9	AG Reversal	
Ideological Aspects of Inequality		
Games of strategy	T10	AG Reversal	
Emphasis on self-reliance	F3	Monotonic	
Emphasis on obedience	F3	Monotonic	
Sexual and Reproductive Inequality		
Polygyny allowed	T10	AG Reversal	
Maximum harem size	T11	AG Reversal	

Note: The monotonic pattern is one in which HG < SH < AH < AG (where inequalities refer to a measure of inequality); the AG reversal pattern is one in which HG < SH < AH > AG.  

Figure 1.  Lenski’s ecological-evolutionary taxonomy of societies.  Arrows represent common patterns of societal evolution.  Redrawn and modified from Lenski, Nolan, and Lenski (1995:82, Figure 4.1).

Figure 2.  Trends in freedom for elites and for the average members of societies.  Redrawn and modified from Nolan and Lenski (1999:384, Figure 16.1).

Figure 3.  Importance of Self-Reliance and Obedience in Socialization, by Type of Society (Means and Standard Errors).  Note: R2 of regression on Type of Society indicators (with HG omitted) is .153 for Importance of Self-Reliance (N=139) and .129 for Importance of Obedience (N=140).  Type of Society: see Table 1.  Importance of Self-Reliance is calculated as the average of SS V306 to V309, Inculcation of Self-Reliance in Early Boy, Early Girl, Late Boy, and Late Girl, respectively.  Each variable is coded on a scale from 0 = No inculcation or opposite trait to 9 = Strong inculcation.  Importance of Obedience is calculated similarly as the average of SS V322 to V325.