The second and third parts of this book classify the economic systems of foraging and agricultural societies in the SCCS based on correlations between their institutions of property an distribution. These economic types are then examined for relationships with other social, political, demographic, and environmental factors in order to draw tentative conclusions regarding the origins of the Agricultural and Industrial Revolutions. The fourth part of the book uses cross-national data to examine similar associations in industrial/service economies, and is not included here.

This article uses factor analysis to identify the key variables underlying the many cross-cultural associations reported by Textor (1967). Twelve factors are identified.

In "The Urban Revolution" (1950), V. Gordan Childe hypothesized ten traits of civilization: urban centers, occupational specialization, monumental buildings, taxation by and/or tribute to elite, isolation of ruling group(s), writing, art, long-distance trade, social solidarity reinforced through common ideologies, and state formation. The author of this study analyzes these traits, and in particular, the presence of written language, with data from two different databases, one ethnographic and one archaeological. He finds that written language is highly correlated with the other traits of civilization as hypothesized by V. Gordan Childe.

Researchers investigated the variation of land tenure systems across forager societies using the economic defensibility model. The study attempted to explain the variation in tenure systems across 30 hunter-gatherer societies. Using data on defense and sharing of resources among groups, and indicators of resource density, resource predictability, and competition for resources, the researchers were unable to explain the variation. This study highlights the vast range of diversity and complexity of foragers subsistence strategies, and proposes that it may be more telling to conceptualize tenure systems among hunter-gatherer societies as assemblages of multiple property regimes. While there was no overall evidence that environmental variables of resource density and predictability explain variation in tenure systems, researchers did find that increasing population density, and greater competition for resources leads to greater territoriality.

The social control hypothesis suggests that ritual human sacrifice may have played an important role in the evolution of social stratification, functioning to legitimize class-based power distinctions by pairing displays of ultimate authority with supernatural justifications. Authors test this hypothesis about human sacrifice with a phylogenetic analysis of 93 Austronesian cultures.

Considerable disagreement exists in regard to the origin and distribution of economic phenomena such as money, slavery, markets, exchange, and imbalanced transfers. Here the author utilizes a worldwide cross-cultural sample of 60 pre-industrial "societies" to empirically test many economic hypotheses, with a focus on distributional mechanisms and institutions.

The authors examine correlations between slavery and variables that can potentially be detected archaeologically. The authors do not test specific hypotheses, but aim to explore the variables in a broader sense. As such, the authors use a grounded theory approach to data analysis in order to examine trends that emerge from the data itself.

This study examines the relationship between population pressure and socioeconomic complexity in a cross-cultural sample of hunter-gatherer groups. The author suggests a causal component to the positive correlations found, arguing that increasing population pressure on food resources requires increasing storage dependence, which in turn drives sedentism and other indicators of socioeconomic complexity.

This article aims to answer the question: Does the imagery of composite beings, also known as monsters, appear cross-culturally? The authors use the Standard Cross-Cultural Sample to test whether these mythical figures are universal and which sociocultural variables might be related to their presence or absence. To do so, they use the ten measures of cultural complexity by Murdock and Provost (1973): writing and records, fixity of residence, agriculture, urbanization, technological specialization, land transport, money, density of population, level of political integration, and social stratification. The results show that the concept of "monsters" is common among cultures, but not universal. Additionally, the presence of composite beings is related to all the measures of cultural complexity. Finally, the authors wanted to test which variables are more relevant. They use a machine learning method (decision trees and random forests), which suggests that the most important variables are social stratification and higher inter-group contact facilitated by land vehicles.

The authors evaluated an alternative theory to the traditional productivity theory. They posit that food surplus did not precede the emergence of hierarchy, rather, the productivity advantage of cereal cultivation over tubers and roots as the catalyst for state societies. Their theory found support with a sample of societies from the present-day, Classical Antiquity, Neolithic period and pre/post Columbian Exchange. The results suggest social complexity emerged with cereal cultivation, rather than agriculture alone.