The study builds on a previous study with the Maasai suggesting that matrilineal descent will close that gap of competitive behavior between men and women. The author conducted a lab experiment consisting of 614 individuals representative of 27 ethnic groups in the Democratic Republic of the Congo. In the experiment, the participants completed a timed matching game. First, they played alone with the goal to complete 5 games within 5 minutes to win money. Next, they competed against an undisclosed opponent to complete the most games and to keep all of the winnings. Finally, the participants were able to choose which pay they preferred based solely on the results from the first round. This was designed to reflect competition preference and results indicated that women were less likely to engage in competition regardless of kinship system.

Lowes and Nunn test the theory that the transatlantic and Indian Ocean slave trades of the thirteenth to nineteenth centuries prompted a shift towards matrilineal kinship systems throughout sub-Saharan Africa. Controlling for ecological variables commonly thought to affect kinship structure (including ruggedness of terrain, suitability for agriculture, etc.), the authors find a significant correlation between the number of people enslaved from a given ethnic group, and the tendency of that group towards a matrilineal kinship system. Polygyny was also identified as a statistically significant characteristic of communities most impacted by the slave trade.

This article examines the effect of infant care on women's contribution to subsistence. Results suggest that women who begin supplementary feeding of their infants early participate in subsistence activities to a greater degree than women who begin supplementary feedings later.

This article examines variation in kinship terminology. The authors develop a new typology of kinds of kinship terminologies, and they propose that terminologies will distinguish siblings of the same and opposite gender when there is a cultural emphasis on cross-sex relations. Empirical analysis supports that a prolonged post-partum sex taboo (rather than sibling avoidance) predicts the presence of a primary cross-parallel component in sibling terminology.

The authors compare language phylogenies and spatial distributions with folktale frequencies of Indo-European peoples in order to reconstruct their cultural transmission. A stronger association is found between folktale frequency and language phylogeny than has been proposed in earlier literature studies, indicating that vertical transmission is more influential on folktale distribution than horizontal transmission through spatial proximity. Finally, the frequencies of certain folktales appear to trace the ancestral divergences of Indo-European languages to a much deeper level than previously though, suggesting that folktales are representative of broader features of culture, rather than recent literary inventions.

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 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.