Grooming of conspecifics is thought to play an important social role among nonhuman primates, but the function and relative importance of such grooming among humans is unknown. Here the authors compare time spent grooming and conversing among six small-scale societies with grooming data from 69 nonhuman primate species. They test the hypothesis that conversation evolved among humans as an alternative way to obtain the social benefits (such as building and maintaining social alliances) of grooming in large groups.

While it is widely accepted that there are a multitude of variables that contribute to a society’s level of democracy, the authors of this study argue that the prevalence of consanguinity is one that is often overlooked. Using a sample of 70 nations, they tested the relationship between consanguinity (defined as marriage and subsequent mating between second cousins or closer relatives) and level of democracy (defined by both the Polity IV scale and the EIU Index) and found a significant negative relationship. Similarly, when controlled for a host of different variables in multiple regression analysis, the significant relationship between consanguinity and level of democracy held true.

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 study explores predictors of variation in two dimensions of marital residence patterns among hunter-gatherers: 1) the tendency toward patrilocality versus matrilocality and 2) the tendency toward unilocality versus bilocality.

The present research investigates food sharing and labor sharing practices of 98 nonindustrial societies. The aims are to: 1) document the frequency and scope of sharing, and 2) test the theory that greater sharing is adaptive in societies subject to more resource stress (including natural hazards).

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.

This article uses the Standard Cross-Cultural Samples to test the relationship between disease and economic growth among sub-Saharan African societies. The authors suggest that a higher disease prevalence limits social integration and economic development since pre-colonial times. The variable measuring economic growth is the complexity of large or impressive structures. The hypotheses are that 1) pathogen stress is negatively correlated to the presence of complex buildings, and 2) pathogen stress is positively correlated to increased ethnic diversity. The results support both hypotheses, and there are additional results, like 1) the negative correlation between pathogen stress and current income per capita and 2) the negative correlation between the increased ethnic diversity and current income per capita. Overall, this article shows the robust relationship between disease and economic development.

This study relates the type of games present in a society to the level of cultural complexity. Authors use a "game-type combination scale" that categorizes societies as having: 1) games of physical skill only; 2) games of physical skill and games of chance; and 3) games of physical skill, games of chance, and games of strategy. Results show a relationship between the game-type combination scale and indicators of cultural complexity.

This article considers the consequences of modernization. Factor analysis is used to identify four stages of modernization: 1) changes in education, government, and trade; 2) changes in health, technology, and transportation; 3) changes in family, religion, and toilet; and 4) changes in behavior. The authors then consider five trends they expect to be associated with modernization and test whether they develop over the course of the four stages. Results indicate that these 5 trends—increased cultural complexity, female status, pacification, suicide, and social stress—are associated with only the first and fourth stages.

This article investigates a cultural patterning of altered states of consciousness. The authors use an ordinal variable for a society's trance type; its four levels are 1) trance, 2) trance and possession trance, 3) possession trance, and 4) neither type. Results suggest that trance type is associated with measures of societal complexity and subsistence economy. Regional differences and the effects of diffusion are also examined.