This study examines socio-economic predictors of political complexity. Findings suggest that class stratification is the most significant predictor of political complexity.

The biological success derived from cumulative culture and cooperation and their association with ancestral group structure is examined. It is suggested that inclusive fitness cannot explain extensive cooperation in hunter-gatherers because in most of the foraging societies examined, most individuals in residential groups are unrelated. These large social networks may explain why humans are capable of social learning.

This study examines instances of group fission cross-culturally. Results suggest that internal political conflict and resource scarcity are the two most common causes of group fission. Results also suggest that group fission tends to occur along kin lines.

The authors predict that fitness outcomes will be negatively associated with spousal relatedness among foragers but positively associated among non-foragers, due to the greater social benefits of intensive kinship systems among non-foragers. Support is found for this hypothesis; however, an interaction effect is discovered with inbreeding, which appears to account for the variability in these relationships independent of subsistence activity. The authors qualify this support in order to explain why the incidence of cousin-marriage in non-foraging societies is not higher.

This study attempts to reconstruct ancestral marriage practices using hunter-gathers' phylogenies based on mitochondrial DNA sequences. Data suggest that arranged marriages and brideprice/bridewealth likely go back at least to the first modern human migrations out of Africa and that early ancestral human societies probably had low levels of polygyny.

This article examines whether intergenerational wealth transmission perpetuates inequality among hunter-gatherers. The authors consider three types of wealth: embodied, material, and relational. Empirical analysis of wealth transmission in five cultures suggests that, in many cases, a parent’s wealth is associated with a child’s life chances. Gini coefficients suggest that hunter-gatherer cultures have low to moderate wealth inequality overall: very low by current world standards but not non-existent.

This article examines marital residence and sibling coresidence among horticulturalists in the South American lowlands. The authors reject a hypothesis that patrilocality is the defining trait of Amazonian tropical forest culture. Results on horticulturalists are compared with findings on hunter-gatherers: horticulturalists tend to be more uxorilocal. Empirical analysis also suggests that women tend to live with more kin later in life, and in large villages headmen live with more kin than nonheadmen.

This article presents the results of economic behavior experiments conducted on members of 15 small scale societies. Although three different economic experiments were conducted, findings focus on the results of the "Ultimatum Game." The authors found that no society adhered to behavior predicted by the "selfishness axiom" which suggests that individuals will behave in a way that maximizes their own gain. Authors also discuss possible predictors of behavioral variation within and between groups.

This article explains the variation in inequality using a model in which a population's inequality depends on the extent to which its most important forms of wealth are transmitted within families across generations. Results suggest that economic systems differ substantially in the intergenerational transmission of wealth.

In this article, the authors reconsider the polygyny threshold model in order to account for the "polygyny paradox." This paradox, as the authors define it, is the trend away from polygyny as societies adopt stratified agricultural economies. This is despite an increase in both the importance of material wealth and greater leaves of wealth inequality both of which would otherwise suggest increased polygyny. The authors develop a new model that does account for this paradox.