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.

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.

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

This paper builds off previous research into the effect of population size and resource risk on complexity of subsistence technology by investigating the relationship between these independent variables and total number of material items and techniques used by various western North American hunter-gatherer groups. This tally of total technological complexity is found to be insignificantly related to population size or residential mobility; however, there is a significant correlation in the expected direction between technological complexity and one measure of resource risk (mean annual temperature during driest month). Tying this finding to previous analyses of subsistence technologies, the authors theorize that environmental risk is a pervasive driver of technological ingenuity and cultural evolution.

The authors test the relationship between ethnolinguistic area and various environmental variables in a cross-cultural sample of hunter-gatherer, pastoral, and agricultural subsistence groups in order to evaluate various hypotheses surrounding the geographic and ecological origins of cultural diversity. They propose that societies which adopted agriculture at the beginning of the Holocene were less directly affected by climate which, combined with the effect of increasing political and cultural complexity, allowed coordination and homogenization of ethnolinguistic groups over a broader swathe of territory.

The authors present a bioeconomic model of hunter-gatherer foraging effort to quantitatively represent forager intensification. Using cross-cultural data, the model is evaluated as a means to better understand variation in residential stability and resource ownership.

This article focuses on the effect of environmental extremes and unpredictability on human behavior and reproductive strategies. Significant correlations were found between environmental extremes and unpredictability and several variables, including mobility, subsistence mode, and degree of polygyny.

Using a representative sample of 339 hunter-gatherer societies, researchers examine the relationship between hunter-gatherer use of space, size of population and supply of resources to see if they are similar to other organisms. By combining all factors into a single model, the authors claim to explain 86% of the variation in home range. Hunters have greater resource distribution than gatherers but both more so than aquatic foragers. Lastly, terrestrial foragers have more extensive home ranges than aquatic foragers.

Do tropical hunter-gatherers follow the diet known today as the Paleo diet? Using nutritional data on 11 tropical hunter-gatherer groups, this study asses dietary composition. The results show that there are high levels of variation in the distribution of protein, fat, and carbohydrates among the sample of 11 hunter-gatherer groups.

In this study, the authors draw from intensity theory and combine previous research from the fields of behavioral ecology, economics, and social evolution to analyze drivers in the emergence and persistence of inequality across the world. They propose that environmental heterogeneity and circumscription (the difficulty of moving and establishing oneself in a new environment relative to remaining in the current one) play a significant role in the stratification of societies. Their results indicate that situations arise from various environmental conditions and levels of circumscription that may result in an individual giving up autonomy for material gain, thus favoring inequality.